ARISTOTLE ON SPONTANEITY

by

Alessandro Bonello

A thesis submitted in conformity with the requirements

For the degree of Doctor of Philosophy

Department of Philosophy

University of Toronto

© Copyright by Alessandro Bonello, 2015

ii

ARISTOTLE ON SPONTANEITY

Alessandro Bonello

Doctor of Philosophy

Department of Philosophy

University of Toronto

2015

Abstract

Ordinary living beings, according to Aristotle, are generated by parents of the same kind. They are

exemplary instances of substances, and their generation is a paradigmatic application of his theory

of causality. Yet Aristotle believes that numerous organisms are not generated by parents of the

same kind, but are spontaneously generated. Many commentators tend to dismiss these cases as

phenomena that fall beyond what in nature occurs ‘always or for the most part’. I argue that this is

incorrect: spontaneous generation is as regular, common, frequent, and predictable as the generation

of living beings by parents of their own kind. Some authors have claimed that the regularity of

spontaneous generation is such as to threaten Aristotle’s general theory of causality and the

metaphysical principles on which it rests. I show the fallacies behind this position, and argue that

Aristotle emphasizes the ontological peculiarity of spontaneously generated creatures and provides

appropriate principles to justify their existence in the natural world. Other authors have argued that

the account of spontaneity presented in Historia Animalium and De Generatione Animalium is

inconsistent with the analysis of spontaneity offered in the Physics and the Metaphysics. I argue that

this view rests on the mistaken assumption that the Physics and the Metaphysics present a univocal

account of τὸ αὐτόματον. I then read Physics B 4-6 and Metaphysics Z 7-9 independently of one

another, and show that τὸ αὐτόματον is, in Aristotelian terms, an equivocal phenomenon. I argue

that while the Metaphysics offers an account of the spontaneous generation of individual organisms,

which Aristotle endorses in his biological works, the Physics presents an account of the chance

generation of entire species of organisms, which he rejects.

iii

Acknowledgements

It is a great pleasure for me to acknowledge the people who helped me to write this thesis. I have

been very fortunate to receive the support and guidance of a committee of extraordinary scholars:

Jennifer Whiting, Brad Inwood, and Denis Walsh. Thanks to Denis Walsh for stimulating my early

thinking about some of the issues I developed in this dissertation, and for being amenable to the

many changes that the thesis has gone through. Towards Brad Inwood I feel sincere gratitude and

deep admiration and respect. His sharp comments made me see with clarity both the promising and

the hopeless parts of my work. His invaluable advice helped me to stay grounded. He is an inspiring

figure, and I owe to his teachings my deep love for ancient Greek language. Jennifer Whiting, my

supervisor, deserves my heartiest gratitude. I benefitted from her vision, which helped me to find

the right project for my dissertation, and to see the underlying structure of my ideas. I thank her for

teaching me the virtues of intellectual dedication, tenacity, and rigor. Above all, I want to express

my deep gratitude for her unfailing commitment to my education. As a teacher and mentor, she did

something truly wondrous: she motivated and challenged me to think independently. I am very

grateful to Lloyd Gerson, my internal examiner, for showing me how relevant and important ancient

philosophy is. As his teaching assistant for five years, I have learned a lot from him. I would like to

thank Hendrik Lorenz, my external examiner, for his written and oral comments, which helped me

to clarify and refine my ideas. His advice and encouragement meant a lot to me. As a student of

ancient philosophy, I am privileged to have worked and learned from a group of such remarkable

teachers. I would also like express my sincere gratitude to David Bronstein, whose brilliant

comments on the first paper I wrote on this subject crystallized the problem that motivated this

whole thesis. It was an authentic honor to share part of my graduate studies with him. Lastly, I want

to express my deep gratitude to my family and friends for their love and support over the years. I

was blessed with the friendship of Juan Pablo Bermudez, Cameron Woloshyn, and Charles Repp,

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who helped me to see the deeper meaning of this work. A special thanks goes to Natalie Sanchez,

who patiently read and edited the last three versions of this work, who never failed to support and

help me, and who infused my days with love, goodness, and beauty. Without her this work would

not have been possible. Most of all, I want to thank my family: my father, Sergio Bonello, my

mother, Claudia Forin, and my sister, Giulia Bonello. In the absence of words to express how

important their support was in my life and my education, I dedicate this work to them.

v

Table of Contents

Part I

τὸ αὐτόματον in Historia Animalium and De Generatione Animalium

1. Introduction 2

2. Spontaneous Generation is Regular 6

3. Spontaneous Generation is Common 13

4. Spontaneous Generation is Not Contrary to Nature 19

5. Spontaneous Generation is Frequent 26

6. Spontaneous Generation is Causally Uniform 31

7. Species of Spontaneously Generated Creatures are Not Eternal 39

8. Spontaneous Generation is Not Reducible to Ordinary Causal Analysis 45

9. Spontaneous Generation Occurs κατὰ φύσιν, Not φύσει 53

10. Spontaneous Generation is Not Inconsistent with Aristotle’s Metaphysical Principles 61

Part II

τὸ αὐτόματον in the Physics and the Metaphysics

1. Introduction 70

2. Random Spontaneous Generation in Metaphysics Z 7-9: The Standard Interpretation 81

3. Regular Spontaneous Generation in Metaphysics Z 7-9: An Alternative Interpretation 93

4. Spontaneity in Physics B 4-6: The Standard Interpretation 104

5. Chance in Physics B 4-6: An Alternative Interpretation 115

6. Spontaneity is Not an Accidental Cause 131

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7. The Equivocity of τὸ αὐτόματον: Chance and Spontaneity 146

8. The Spontaneous Generation of Living Beings 158

9. The Generation of Living Beings by Chance 167

10. Conflict without Contradiction 178

BIBLIOGRAPHY

1. Aristotle’s Texts and Translations 186

2. Texts of Other Ancient Authors 187

3. Secondary Sources 188

1

Part I

τὸ αὐτόματον in Historia Animalium and De Generatione Animalium

2

1. Introduction

In the world of nature, according to Aristotle, many things are and come to be ἀπὸ τοῦ αὐτομάτου.

The generation of living beings ἀπὸ τοῦ αὐτομάτου, generally referred to as ‘spontaneous

generation’, offers perhaps the most notorious and striking example. Yet, this aspect of Aristotle’s

philosophy of nature is only marginally dealt with in general studies of his thought: while some

choose to ignore it altogether, others treat it as a topic of secondary importance. Moreover, when

this phenomenon is in fact included, it is generally mentioned as an example of the most obsolete

aspects of Aristotle’s biology, a mistake stemming from inaccurate observations and the acceptance

of ancient prejudices and popular superstitions.1 At the same time, Aristotle’s mistake is often

presented as being concerned only with an overall minor or negligible phenomenon, hence

excusable and dispensable from the scientific point of view.2 Even in most works on Aristotle’s

philosophy of nature, spontaneity – τὸ αὐτόματον – is presented as something contrary to nature,

that is, as an exception to what is generally regarded as the normal pattern of development of

organisms. Living beings generated ἀπὸ τοῦ αὐτομάτου are often counted as products of mistakes

and failures in nature, which occasionally disturb the more regular order of natural events, on par

with the occurrence of monstrosities and freaks. Hence spontaneity is often presented as something

unusual and atypical, in other words, as an accident interfering with the orderly and predictable

course of nature, therefore falling outside the boundaries of genuine scientific knowledge. What is

even more striking is that the tendency to neglect the importance of spontaneous generation and to

relegate the question of spontaneity to a marginal position affects not only general presentations of

Aristotle’s philosophy and specific studies on his natural philosophy, but also studies that stress the

centrality of biology and biological theories in his thought.3

1 Cfr. DÜRING [1966]; BYL [1980] and [1986]; BYL and SCHOULS [1990]; and JOLY [1968].

2 Cfr. BOSTOCK [2006], pp. 60-61.

3 Cfr. HANTZ [1939], p. 20; RANDALL [1960], p. 183; GRENE [1963], p. 152; and GRENE & DEPEW [2004], p. 7:

“Aristotle thinks that just because natural substances have an internal principle of change and rest, their behavior is, to

3

Although this general view may be surprising given the scope and importance which, in his

biology, Aristotle assigns to τὸ αὐτόματον in the account of the generation of living beings, such a

tendency to confine what comes to be ἀπὸ τοῦ αὐτομάτου to an accidental and exceptional aspect of

the world may be the result of some of Aristotle’s own claims. In several works throughout the

Corpus, in fact, Aristotle asserts that τὸ αὐτόματον is to be found “besides what is or comes to be

always or for the most part (παρὰ τὸ ἀεὶ καὶ τὸ ὡς ἐπὶ τὸ πολὺ ἢ ὂν ἢ γινόμενον)”.4 As is well

known, the theoretical foundation of all these claims is found in Physics B 4-6 – generally regarded

as Aristotle’s treatise on chance – in which Aristotle explains that the unusual, irregular, and

exceptional character of what comes to be ἀπὸ τοῦ αὐτομάτου stems from the fact that τὸ

αὐτόματον is an accidental cause (αἴτιον κατὰ συμβεβηκός).5 This would not only explain the

alleged infrequency and irregularity of such occurrences, but would also provide a justification for

the view that what comes to be ἀπὸ τοῦ αὐτομάτου is random (ὅπως ἂν τύχῃ),6 indeterminate

(ἀόριστον),7 obscure to the human mind, and not a proper subject of scientific understanding

(ἐπιστήμη).8 As a result, most scholars have tended to interpret the theory of the generation ἀπὸ τοῦ

αὐτομάτου of living beings exclusively in terms of the account of τὸ αὐτόματον presented in the

Physics, and, paradoxically, to disregard all other information on the subject contained in the pages

one degree or another, predictable and regular (Physics 198 b 35). What happens spontaneously or by coincidence does

not conform to this pattern. Nor does what happens by external force, which makes a natural process deviate from its

built-in pattern of motion. In other words, Aristotle denies that what happens spontaneously, coincidentally, or by force

can be regular and lawlike. He also denies that what happens spontaneously, by chance, or by force can be the object of

scientific knowledge. For scientific knowledge depends on logically necessitated demonstrations from secure first

principles, as we have already noted, and Aristotle thinks that only non-incidental changes in the objects of a science

can be necessitated in this way. For Aristotle, what is spontaneous, chancy, or forced cannot be scientifically known

(Physics 199 a 1–6).” 4 Cfr. Phys. B 5, 196b 12-13, 20, and 196b 36 – 197a 1; 197a 20, and 34-5; B 8, 198b 36; 199b 24-24; cfr. also De Gen.

et Corr. II 6, 333b 6-7; De Caelo A 12, 283a 32 – 283b 1; Eth. Eud. VII 14, 1247a 31-33; Rhet. I 10, 1396a 32-34. 5 Phys. B 5, 196b 23; 197a 5-6, 12-14, and 33; B 6, 198a 6-7; Metaph. E 2, 1026b 31-33; 1027a 7-8 and 26; Metaph.

30, 1025a 14-15; Metaph. K 8, 1065a 1-3, 28, 30, and 34. 6 Phys. B 4, 196a 22; B 5, 197a 22; Metaph. E 2, 1027a 17; Metaph. 30, 1025a 25; Metaph. K 8, 1064b 36; cfr. also

De Caelo II 5, 287b 24-25 and B 8, 289b 25-27 7 Phys. B 5, 196b 28; 197a 8, 9, and 20-21; B 6, 198a 5; Metaph. 30, 1025a 25; Metaph. K 8, 1065a 25, 32-33; cfr.

also An. Pr. A 13, 32b 10; Rhet. I 10, 1396a 32-34 8 Phys. B 4, 196b 6; B 5, 197a 10 and 18; Metaph. E 2, 1026b 3-5 and 26-27; 1027a 19-21; Metaph. K 8, 1064b 17-19,

30-32, 1065a 3-6, 33-34; cfr. also An. Post. A 30, 87b 19-21.

4

of Aristotle’s biological works, where the spontaneous generation of living beings is studied at great

length and described in great detail.

Yet this oversight severely affects our understanding of Aristotle’s account of spontaneity,

and thus ought to be rectified. The exclusive focus on the account of τὸ αὐτόματον in the Physics

and the uncritical application of this account to the spontaneous generation of living things in fact

prevents a correct appreciation of the phenomenon of spontaneity in Aristotle’s biological works,

and conceals, rather than illuminates, the authentic significance of the Physics’ account of τὸ

αὐτόματον to Aristotle's biological works. Hence, to address this shortcoming, we need to begin our

study by looking at Aristotle’s biological works, and determining the whole range of aspects that,

according to Aristotle, characterize the phenomenon of spontaneity.

Indeed, upon a close examination of the zoological treatises, we discover that Aristotle’s

observations on spontaneously generated beings do not appear as a collection of oddities, or as the

subjects of anecdotal curiosity to be contrasted with the proper scientific treatment devoted to

animals that reproduce their own kind.9 On the contrary, biological spontaneous generation appears

as a common, frequent, and regular natural phenomenon, indistinguishable in these respects from

the generation of living beings by parents of the same kind, which Aristotle treats as the

paradigmatic instance of what happens ‘always or for the most part’. Thus, in this context, the

spontaneous generation of living beings appears to be granted the same theoretical consideration as

the generation of animals that are sexually reproduced, and to evoke the same sense of curiosity and

wonder as that which inspires the observation of all other living creatures. From the point of view of

Aristotle’s biological studies, living beings generated ἀπὸ τοῦ αὐτομάτου do not appear as

9 By ‘animals that reproduce their own kind’ I mean animals that generate offspring of the same species. In other

contexts, I use the term ‘kind’ in an inclusive sense to refer to any group of organisms with shared characteristics, at

any level of generality (species, genera, and higher taxonomical ranks), thereby maintaining the same flexibility found

in the many instances of Aristotle’s use of the terms ‘γένος’ and ‘εἶδος’ (cfr. Part I, Chapter 7). In contexts where a

distinction between different levels of generality becomes relevant (cfr. especially Part II, Chapters 2 and 3), I use the

term ‘kind’ in an exclusive sense to refer to any group of organisms with shared characteristics, at a higher level of

generality than the species. In those contexts, I emphasize the distinction by contrasting ‘individual species’ and

‘general kinds’.

5

something uncommon, rare, or inscrutable to human understanding, but as an integral part of the

extraordinary variety of life forms attesting to the intrinsic complexity, order, and beauty of nature,

the contemplation of which can provide genuine insight into the way in which nature works.

Contrary to the general opinion presented in non-specialized literature, the few specialized

studies that are dedicated to spontaneous generation in Aristotle’s biological works invariably

recognize that the most striking feature of spontaneous generation is, in fact, its manifest regularity.

Scholars of different orientations who have scrupulously analyzed the generation ἀπὸ τοῦ

αὐτομάτου of living beings in the Historia Animalium and De Generatione Animalium all agree that

in one precise sense of the expression, spontaneously generated creatures belong to the class of

things that ‘are or come to be always or for the most part’. And yet, despite their underlying

agreement in this particular regard, there remains much confusion and controversy about the exact

extent of such regularity and its implications. Much of this confusion stems from the fact that

different scholars use the expression ‘regularity’ to mean different things. Here again, we should

recognize that the root of this confusion may very well be due to the fact that Aristotle himself uses

the expression ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ in different senses, and that no study, as of yet, has brought

to the surface and systematically organized the entire range of different meanings of this expression.

In order to have a complete and accurate understanding of Aristotle’s biological theory of

spontaneous generation, therefore, it is necessary investigate the different aspects of spontaneous

generation that fall within the scope of what occurs ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’, according to its

different senses. The purpose of this task is fourfold: to present relatively uncontroversial points

regarding spontaneous generation raised in Aristotle’s biological works; to rid his theory of

common misconceptions and misrepresentations; to highlight aspects of his theory that have been

ignored; and to solve the most important challenges posed by such a theory.

6

2. Spontaneous Generation is Regular

When we confront Aristotle’s major biological works, what immediately emerges as the most

noteworthy aspect of spontaneous generation is that it is a form of γένεσις that distinguishes entire

classes of living beings. Aristotle, in fact, claims that spontaneous generation is a mode of

generation that characterizes entire kinds of plants and animals, the latter of which include almost

all the different species of shellfishes, many species of insects, and a few species of fishes, like eels

and a certain variety of mullets.10

In both the Historia Animalium and the De Generatione

Animalium, spontaneity is the very first topic, which Aristotle introduces when he undertakes his

study on the different modes of generation of living beings. Thus, far from treating it as an

exception within the domain of the living, and far from restricting it to isolated one-off cases,

Aristotle presents spontaneity at the outset of his study as one of the most fundamental forms of

generation categorizing entire kinds of living beings.

In the opening lines of Historia Animalium V 1 – the first of two books in this work that

focus on the generation of living beings – spontaneity plays a privileged role. After providing a

summary of the previous books’ study on the internal and external parts of animals, their senses,

and the duality of sex, Aristotle presents an organizational plan for the study of the different modes

of generation of living creatures:

It now remains for us to discuss their modes of generation (περὶ τῶν γενέσεων αὐτῶν), beginning

first with the first (καὶ πρῶτον περὶ τῶν πρώτων). These modes are many and diverse, (εἰσὶ δὲ πολλαὶ

καὶ πολλὴν ἔχουσαι ποικιλίαν) and in some respects they are unlike (καὶ τῇ μὲν ἀνόμοιοι), whereas

in other respects they resemble each other (τῇ δὲ τρόπον τινὰ προσεοίκασιν ἀλλήλαις). Since the

kinds have already been divided (ἐπεὶ δὲ διῄρηται τὰ γένη πρότερον), we must attempt to follow the

same divisions in our present investigation; except that whereas in the former case we started with a

consideration of the parts of man, in the present case we ought to treat of man last of all because he

involves most discussion. We shall commence, then, with shellfishes (πρῶτον δ’ ἀρκτέον ἀπὸ τῶν

ὀστρακοδέρμων).11

10

For a list and a comprehensive discussion on the major kinds of creatures spontaneously generated cfr.

McCARTNEY [1920], BALME [1962], QUINN [1964], LOUIS [1968], MARTINS [1990], and LLOYD [1996]. 11

Hist. An. V 1, 539a 1-9. Unless otherwise indicated, all translations of Aristotle’s works are usually modified versions

of those that are found in The Revised Oxford Translation (BARNES [1984]).

7

In the theoretical framework of the Historia Animalium, spontaneously generated creatures – which

in this passage Aristotle alludes to by referring to shellfishes – find their precise place within the

ordered articulation of all the different kinds of living beings. This order, which Aristotle sets forth

through a method of διαίρεσις, reveals all the differences (διαφοραί) and similarities (ὁμοιότητας)

present in the ‘many and diverse (πολλαὶ καὶ πολλὴν ἔχουσαι ποικιλίαν)’ modes of generation,

which exist among the various classes (γένη) of living beings.12

Within this context, we discover

that spontaneous generation – here alluded to by the reference to the γένος of shellfishes, whose

generation is considered worthy of being studied first (πρῶτον) – is similar to other forms of

generation that do not involve copulation. In fact, in Historia Animalium V 15, where the research

on generation here announced properly begins, Aristotle claims that:

We must now proceed to treat of generation both with respect to animals that copulate and those that

do not, and we shall begin by discussing first the generation of shellfishes (καὶ πρῶτον περὶ τῶν

ὀστρακοδέρμων), for this is almost the only kind that in its totality does not reproduce by copulation

(τοῦτο γάρ ἐστιν ἀνόχευτον μόνον ὡς εἰπεῖν ὅλον τὸ γένος).13

After presenting a plan for the study of animal generation in Historia Animalium V 1, Aristotle goes

on to introduce the most basic distinction among the different modes of reproduction:

Now there is one property that animals are found to have in common (κοινόν) with plants. For some

plants are generated from the seed of other plants, whereas other plants are spontaneously generated

(τὰ δ’ αὐτόματα γίνεται) through the formation of some principle similar to a seed; and of these

some derive their nutriment from the ground, whereas others grow inside other plants (τὰ δ’ ἐν

ἑτέροις ἐγγίνεται φυτοῖς), as is mentioned in the treatise on Plants. In the same way, among animals,

some are generated from animals according to the kinship of the form (τὰ μὲν ἀπὸ ζῴων γίνεται κατὰ

συγγένειαν τῆς μορφῆς), whereas others grow spontaneously and not from kindred animals (τὰ δ’

αὐτόματα καὶ οὐκ ἀπὸ συγγενῶν); and of these some come from putrefying earth or vegetable

12

BALME [1961], pp. 211-212, arguably the first modern scholar to have shown the extensive presence of such a

diairetic methodology in the Historia Animalium, has observed that this work ought not to be considered a “collection

of simple observations”, but rather a theoretical treatise “of all the observable differentiae, collected qua differentiae;”

cfr. also BALME [1987]. Balme is certainly correct about this particular point, for it allows us to recognize, beyond the

unquestionable ‘empirical’ character of the Historia Animalium, the presence in it of a precise theoretical and

methodological structure, albeit different from the one characterizing the De Generatione Animalium, which rests on the

notion of οὐσία and on the articulation of its inner causal structures. For a more historical perspective on the

methodology of διαίρεσις in the Historia Animalium, cfr. also VEGETTI [1971], p. 102-120, and [2007a], p. 133-134. 13

Hist. An. V 15, 546b 14-18.

8

matter, as is the case with a number of insects, while others are spontaneously generated in the inside

of animals out of the secretions of their several organs.14

The distinction between classes of plants whose members are spontaneously generated and classes

of plants whose members are generated from seed is, according to Aristotle, a distinction that plants

have in common (κοινόν) with animals. The same point is made in the opening chapter of De

Generatione Animalium. After drawing a distinction between animals “generated from the union of

animals of the same kind (ὅσα μὲν ἐκ συνδυασμοῦ γίγνεται τῶν συγγενῶν ζῴων)”15

and animals

“generated not from the union of animals but from decaying earth and residues (ὅσα δὲ γίγνεται μὴ

ἐκ ζῴων συνδυαζομένων ἀλλ’ ἐκ γῆς σηπομένης καὶ περιττωμάτων),”16

Aristotle proceeds to claim

that:

The same holds good also in plants (ἔστι δὲ καὶ ἐπὶ τῶν φυτῶν τὸν αὐτὸν τρόπον), some (τὰ μὲν)

coming into being from seed and others (τὰ δ’), as it were, by the spontaneous action of nature

(ὥσπερ αὐτοματιζούσης τῆς φύσεως), arising either from decomposition of the earth or of some parts

in other plants; for some (ἔνια) are not formed separately by themselves (οὐ συνίσταται καθ’ αὑτὰ

χωρίς), but are produced upon other trees, as the mistletoe.17

That Aristotle is seeking to classify entire classes of plants and animals, and not particular

creatures, is evident from the example he use to illustrate his point, namely ‘the mistletoe,’ an entire

species of plants. Thus, the distinction between species whose members are spontaneously

generated and species whose members are reproduced from seed is said to be present not only

among animals, but also and in the same way (τὸν αὐτὸν τρόπον) among plants. Here, Aristotle

seems so intent on emphasizing the specific autonomy of spontaneously generated plants and

animals, that he even takes the liberty of coining a unique and unusual expression: plants and

animals that do not come to be from seed come to be, ‘as it were, from the spontaneous agency of

14

Hist. An. V 1, 539a 15-25. 15

De Gen. An. I 1, 715b 2-3. 16

De Gen. An. I 1, 715a 24-25; cfr. also I 1, 715b 24-25: “ὅσα δὲ μὴ ἐκ ζῴων ἀλλ’ ἐκ σηπομένης τῆς ὕλης.” 17

De Gen. An. I 1, 715b 25 – 716a 2.

9

nature (ὥσπερ αὐτοματιζούσης τῆς φύσεως)’ – an expression which, though unique, parallels his

other claim about “the spontaneous nature (ἡ φύσις αὐτόματος)”18

of shellfishes.

Another interesting case is provided by Aristotle’s discussion of the spontaneous generation

of intestinal worms, formed, as Aristotle had mentioned, in the inside of animals out of the

secretions of their organs:

Of these worms there are three kinds (ἔστι δ' αὐτῶν γένη τρία): one named the flat-worm, another the

round worm, and the third the ascarid. These intestinal worms do not in any case propagate their kind.

The flat-worm, however, in an exceptional way, clings fast to the gut, and produces a seed like that of

cucumber, by observing which indication the physician concludes that his patient is troubled with the

worm (ᾧ γινώσκουσι σημείῳ οἱ ἰατροὶ τοὺς ἔχοντας αὐτήν).19

What is important to notice in this passage is not only the claim that spontaneously generated

intestinal worms can be classified according to distinct γένη, determined according to recognizable

morphological structures, such as the flat and round shape, but also the fact that these γένη are

objects recognized and included within a scientific framework – in the present case, the peculiar

seeds that flat-worms produce, and which appear to be like a cucumber’s seeds, are read as an

empirical sign (σημεῖον) from which doctors can diagnose their presence.20

In his pioneering work on Aristotle’s biology, and in what is arguably the most influential

study on Aristotle’s theory of spontaneous generation, Balme has rightly pointed out that in both the

Historia Animalium and De Generatione Animalium:

A clear distinction is drawn between those animals which are always spontaneously generated and

the remainder, which never are. Spontaneity is therefore not unusual where it occurs; the sense of

παρὰ ὡς ἐπὶ τὸ πολύ is attached not to it but to τέρατα.21

18

De Gen. An. III 11, 761b 23-24. 19

Hist. An. V 19, 551a 8-13. 20

Cfr. LANZA & VEGETTI [1971], p. 319-320: the three worms here described are, respectively, the Taenia solium,

the Trichinella spiralis, and the Ascarides lumbricoides. The diagnosis of the presence of the Taenia is based on the

presence of its proglottids, here described as creatures resembling a cucumber seed. 21

BALME [1962], p. 97 (italics are mine); cfr. also p. 100. Arguably TORSTRICK [1875], p.465, was the first scholar

to point out that spontaneous generation occurs regularly within certain kinds of plants and animals.

10

In a similar way, Dudley, in his monograph on Aristotle’s concept of chance, has accurately

observed that in Aristotle’s biology, “spontaneous generation applies to all members of the class of

living beings that are said to be spontaneously generated and does not apply to any other living

being.”22

Following Balme, scholars have thus designated the theory of the generation ἀπὸ τοῦ

αὐτομάτου of living creatures presented in the biological works as ‘regular spontaneous

generation’.23

In speaking of the ‘regular’ spontaneous generation of living beings, we ought to be

aware of potentially misleading ways of characterizing such phenomena. Bostock, for instance, has

claimed that in the biological works, Aristotle is speaking of “the regular generation of certain

species of animals without seed”.24

Although expressions of this sort are quite common in specialized literature,25

and although

Aristotle himself often resorts to such constructions, it is important to stress the fact that the

generation of living creatures, whether spontaneously or not, is always the generation of particular

living creatures, not species. In other words, Aristotle is not attempting to make a distinction

between species that are spontaneously generated and species that are not, for strictly speaking

species of living beings are, according to Aristotle, not generated. This point is particularly

important to bear in mind, as we shall see, when it comes to understanding Aristotle’s theory of

generation ἀπὸ τοῦ αὐτομάτου and solving one of the most crucial problems often associated with

it.26

Thus, to avoid ambiguities, we ought to formally define ‘regular spontaneous generation’ as the

generation without seed of individual organisms belonging to species whose members are always

22

DUDLEY [2012], p. 193 (italics are mine). 23

Cfr. for instance JUDSON [1991], p. 74; BOSTOCK [1994], p. 139; LLOYD [1996], p.105 and 118; and DUDLEY

[2012], p. 186 ff. 24

BOSTOCK [1994], p. 139 (italics are mine). 25

Cfr. for instance HULL [1967-1968], p. 247, who speaks of Aristotle’s belief in “species which are generated

spontaneously;” LENNOX [1982], p. 220, who claims that “in the Generation and History of Animals, Aristotle argues

that entire genera are generated ἀπὸ τοῦ αὐτομάτου;” GOTTHELF [1989], p. 190, who points out that “even some

blooded animals, such as the eel and some species of river fish, are generated spontaneously;” AGUTTER &

WHEATLEY [2008], Aristotle “believed in spontaneous generation of some species”; and JOHNSON [2012], p 118,

for whom “some kinds of organisms, admittedly very lowly ones, can in fact regularly be generated spontaneously”. 26

Cfr. Part II, Chapter 9.

11

generated without seed; in the same way, when we speak of spontaneously generated creatures as

forming ‘regular kinds’, we mean to say that they form kinds whose members are regularly, indeed

always, generated without seed. It follows, then, that the distinction which Aristotle traces in the

Historia Animalium and in De Generatione Animalium is a distinction between regular kinds –

between species whose members are always generated without seed, and species whose members

are always generated from seed.

According to a famous dialectical precept of the Topics, one useful way to identify the many

senses of a particular expression is to examine whether its contrary (τὸ ἐναντίον) admits of many

senses.27

As our task is to clarify and identify the different aspects of spontaneous generation that

can be said to fall into the category of what is or comes to be ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’, it is

important to point out that scholars after Balme have drawn a distinction between the belief in

‘regular’ spontaneous generation and the belief in ‘random’ spontaneous generation. Contrary to

‘regular’ spontaneous generation, which is the generation without seed of particular organisms

belonging to species whose members are always generated without seed, ‘random’ spontaneous

generation refers to the unusual generation without seed of individual organisms belonging to

species whose members are for the most part generated from seed.28

Only in this ‘random’ form can

spontaneous generation be said to occur ‘neither always nor for the most part (οὔτε ἀεὶ οὔθ’ ὡς ἐπὶ

τὸ πολύ)’, as its occurrence would constitute an exception to the way in which creatures belonging

to a certain species normally come into being. Although several scholars argue that such a theory is

implied by Aristotle’s account of τὸ αὐτόματον in Physics B 4-6 and endorsed in Metaphysics Z 7-

9,29

random spontaneous generation is nonetheless absent from Aristotle’s Historia Animalium and

De Generatione Animalium.

27

Cfr. Top. I 15, 106a 9-17; II 6, 112b 10-12; Eth. Nic. V 1. 28

Cfr. BOSTOCK [1994], p. 138, who defines it as the “irregular and unusual generation, without seed, of animals that

are standardly generated from seed;” and JUDSON [1991], p. 74, who defines it as the “exceptional case in which an

animal normally generated from seed is generated without seed”.

Cfr. DUDLEY [2012], p. 185, 187, and 190. 29

Cfr. Part II, Chapter 1.

12

This much, therefore, can be considered as a relatively uncontroversial point about

spontaneous generation in Aristotle’s biology, a point that can serve as a solid basis for the rest of

our inquiry: Aristotle’s biological works endorse only a theory of ‘regular’ spontaneous generation,

namely the generation without seed of individual organisms belonging to species whose members

are always generated without seed. It is right to say that just as sexual generation applies to all the

specimens of the classes of living beings whose members are said to be sexually generated, with no

exceptions, so too spontaneous generation applies to all the specimens of the classes of living

beings whose members are said to be spontaneously generated, with no exceptions. In this sense,

therefore, biological spontaneous generation is a regular natural phenomenon, on a par with the

‘many and diverse’ forms of generation of living beings by parents of their own kind, which

Aristotle treat as paradigmatic instances of things which are or come to be ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’.

13

3. Spontaneous Generation is Common and Widespread

In a crucial sense of the expression ‘ὡς ἐπὶ τὸ πολύ’ – the one that conveys the notion of ‘regularity’

– spontaneously generated creatures, as Aristotle presents them in his biological treatises, are not

the sorts of things that are or come to be παρὰ ὡς ἐπὶ τὸ πολύ. As Balme has rightly pointed out, in

Aristotle’s biological works this specific sense of the expression ‘παρὰ ὡς ἐπὶ τὸ πολύ’ is not

applied to spontaneously generated creatures, but rather to τέρατα, that is, to the defective or

‘monstrous’ members of particular species, whose generations indeed constitute exceptions to the

way in which creatures belonging to a certain species normally – for the most part – come into

being.30

Yet Balme has also argued that, in a way, spontaneously generated creatures do belong to

the class of things that are or come to be ‘παρὰ ὡς ἐπὶ τὸ πολύ’ if we interpret the expression “in the

equivocal sense that the majority of animals are not spontaneous”.31

Dudley, too, has claimed that

according to Aristotle, “the vast majority of animals are not generated spontaneously”.32

In the same

way, Gotthelf has maintained that although the expression ‘οὔτε ἀεὶ οὔθ’ ὡς ἐπὶ τὸ πολύ’ does not

apply to the spontaneous generation of individual organisms within each individual species, it

nonetheless does apply “to generations as such, across the animal world”.33

And lastly, by relying

on this equivocation of the expression ‘ὡς ἐπὶ τὸ πολύ’, Johnson has claimed that Aristotle can

consistently hold that “for the most part natural things reproduce sexually […] even while

conceding (and in effect maintaining his own position), that some kinds of organisms, admittedly

very lowly ones, can in fact regularly be generated spontaneously”.34

30

Cfr. De Gen. An. I 20, 727b 28-30 and IV 4, 770b 8-17. 31

BALME [1962], p. 97. 32

DUDLEY [2012], p. 191 (italics are mine). 33

GOTTHELF [1989], p. 182 (italics are mine). 34

JOHNSON [2012], p 118 (Johnson’s italics). Johnson is admittedly trying to show that there is no contradiction

between “Aristotle’s principles in the Physics and his conclusions about spontaneously generated organisms in the

biological works” (p. 117). This seems to be the position held also by MATTHEN [2009], p. 342. However, as BALME

[1962], p. 98 had already pointed out, the Physics’ principle that things that come to be ἀπὸ τοῦ αὐτομάτου, come to be

14

To be sure, these authors are right in identifying a different use of the expression ‘οὔτε ἀεὶ

οὔθ’ ὡς ἐπὶ τὸ πολύ’ in Aristotle. Indeed, it is true that, on several occasions, Aristotle does make

an association between what happens ‘ἀεί’ and what happens ‘generally (ὅλως)’, ‘universally

(καθόλου)’, or ‘in all cases (ἐν ἅπασι)’, and between what happens ‘ὡς ἐπὶ τὸ πολύ’ and what

happens ‘in most cases (ἐν τοῖς πλείστοις)’.35

However, from the fact that the majority of species of

living creatures are not spontaneously generated, these authors have sought to justify the claim that

in Aristotle’s biology spontaneously generated creatures are uncommon and rare. This inference,

however, is clearly invalid, and the belief that in the biological works Aristotle regards

spontaneously generated creatures as ‘παρὰ ὡς ἐπὶ τὸ πολύ’ in this sense is plainly false or, at best,

completely arbitrary.

Against the widespread tendency to downplay the importance of spontaneous generation and

dismiss it as a phenomenon of minor importance, Hull had already pointed out that “roughly one

fifth of the animals mentioned by Aristotle are produced exclusively by spontaneous generation.”36

This ratio, substantially correct and not contested by any author, is introduced by Hull in an effort to

show that while the majority of animals are not spontaneously generated, nonetheless spontaneously

generated creatures exist in quite a large number and can hardly be dismissed as rare or uncommon.

We should also consider that, in accordance with Aristotle’s classification of animals according to

the different modes of generation – viviparous, oviparous, ovoviviparous, larviparous, and

spontaneous37

– spontaneous generation is clearly far more common and widespread among animals

‘οὔτε ἀεὶ οὔθ’ ὡς ἐπὶ τὸ πολύ’ can hardly be interpreted in the sense that “the majority of animals are not spontaneous”.

What it means, if anything, is that “in any given product spontaneity appears as an unusual exception”. In the same way,

GOTTHELF [1989], p. 182, points out that according to the Physics’ principle, “most of the members of species in

which there are spontaneous generations should be generated sexually” (italics are mine), but this is not the sense in

which the criterion ‘οὔτε ἀεὶ οὔθ’ ὡς ἐπὶ τὸ πολύ’ is used in the biological works. 35

Cfr. for example Top. V 1, 129a 8-9; An. Post. I 14, 79a 21-22 and De Part. An. III 2, 663b 27-29. 36

HULL [1967-1968], p. 246; cfr. also HULL [1967], p. 318. 37

Cfr. De Gen. An. II 1, 732a 25 – 732b 14.

15

than viviparous generation, and arguably more common and widespread even than larviparous

generation.38

Although in general it is correct to say that the majority (τὰ πλείστα) of animals are not

spontaneously generated, when we consider more in particular each of the major kinds (μέγιστα

γένη) of animals identified by Aristotle, it is not difficult to appreciate that the application of the

equivocal sense of ‘ὡς ἐπὶ τὸ πολύ’ is appropriate only in one case, namely with respect of fishes.

In all other instances, by contrast, the idea that the majority of animals are not spontaneously

generated is either arbitrary or plainly incorrect. This is what we learn from the opening statement

of De Generatione Animalium:

Now some animals (τῶν δὴ ζῴων τὰ μὲν) are formed as a result of the copulation of male and

female, and this is so in all those kinds in which there exist both male and female. But this is not the

case with all animals (οὐ γὰρ ἐν πᾶσίν ἐστιν). Whereas among all blooded animals (ἀλλ’ ἐν μὲν τοῖς

ἐναίμοις ἅπασι), with a few exceptions (ἔξω ὀλίγων), the individual when completely formed is

either male or female, among the bloodless animals (τῶν δ’ ἀναίμων), while some (τὰ μὲν) have both

male and female and hence generate offspring which are identical in kind with their parents, there are

others which (τὰ δὲ) generate indeed, but not offspring of the same kind. Such are the creatures

which come into being not as the result of the copulation of living animals, but out of putrescent soil

and residues.39

In the first sentence of this introductory passage, Aristotle points out that not all species of animals

are formed as a result of copulation since not all species of animals present a distinction between

male and female. This is not to say that the lack of sexual dimorphism is uncommon or rare among

animals; what Aristotle means is that we ought not to assume that sexual dimorphism is universal

among living beings. It is only when he considers the blooded kind of animals that he clearly

distinguishes the majority of species in which sexual dimorphism is present from the ‘few (ὀλίγοι)’

in which it is not. Here, Aristotle is most likely referring to species of fishes that are spontaneously

generated – the eel, a certain variety of mullets, and the so-called ‘froth’ – which are in fact the only

species of blooded animals he believes to be sexually undifferentiated. The same disparity is clearly

38

I base this ratio on the number of different species of animals reckoned by DÜRING [1966], p. 812. 39

De Gen. An .I 1, 715a 18-25 (Translation by A. L. Peck, with modifications).

16

also recognized in a passage of the Historia Animalium where Aristotle claims that “the majority of

fishes (οἱ πλεῖστοι τῶν ἰχθύων)” are born from eggs although “there are some (ἔνιοι) that are born

also from mud and sand,”40

citing as evidence their lack of sexual organs.41

This certainly gives us

reason to restrict the claim that spontaneously generated creatures come to be ‘παρὰ ὡς ἐπὶ τὸ

πολύ’ in the equivocal sense to the class of fishes (and a fortiori of blooded animals). At the same

time, however, we should note that the recognition that spontaneous generation is present also

among the blooded kind is reason to qualify the claim that spontaneously generated creatures are

present only among the lowest animals.

In contrast with what occurs among the blooded kind, it is not the case that spontaneous

generation occurs ‘παρὰ ὡς ἐπὶ τὸ πολύ’ in the equivocal sense when we consider bloodless

animals. As the passage above shows, when Aristotle considers this kind of creature, he uses the

neutral dichotomous construction τὰ μὲν… τὰ δὲ to distinguish species whose members are

spontaneously generated from species whose members are not. Hence, when applied to the

bloodless kind, the equivocal sense of ‘παρὰ ὡς ἐπὶ τὸ πολύ’ appears, at best, as an arbitrary claim.

The same can be said about one of the most important classes of bloodless animals, namely

insects, to which the above passage seems to allude. The use of the dichotomous construction in the

case of spontaneously generated insects is, in fact, quite common. In a similar passage of De

Generatione Animalium, for example, Aristotle claims that “some insects (τὰ μὲν) come into being

by copulation, like birds and vivipara and most fishes (καὶ τῶν ἰχθύων οἱ πλεῖστοι), while others (τὰ

δ’) come into being spontaneously, like some plants”.42

The contrast between insects and fishes,

stressed in both these passages, suggests that Aristotle believes the spontaneous generation of

insects to be a much more common phenomenon than the spontaneous generation of fishes. This

opinion is confirmed not only by the large number of species of insects that Aristotle considers to

40

Cfr. Hist. An. VI 15, 569a 10-13. 41

Cfr. Hist. An. IV 11, 538a 2- 17 and VI 15, 569a 10-13. 42

De Gen. An. III 9, 759a 5-7; cfr. also De Gen. An .I 16, 721a 2-10.

17

be spontaneously generated,43

but also by his explicit recognition that “many insects (πολλὰ τῶν

ἐντόμων)” come from a spontaneous generation.44

Note, too, that in this same passage, Aristotle

reminds us that spontaneous generation is something that is common (κοινόν) among both plants

and animals, a point which he stresses elsewhere in De Generatione Animalium and in Historia

Animalium.

Finally, if we look more closely at shellfishes, which constitute the other major class of

bloodless creatures, we glean that the claim that ‘the vast majority of animals are not generated

spontaneously’ is not just exaggerated or arbitrary, but altogether false. Among shellfishes, in fact,

the ratio between creatures spontaneously generated and those generated after their kind is inverted,

since Aristotle believes that either all (πάντα) shellfishes as a general rule (ὅλως) are

spontaneously generated,45

or else the vast majority of them (τὰ πλεῖστα), with the only (μόνον)

possible exception of land snails.46

Although, then, it is correct to say that most animals are not spontaneously generated, there

is nonetheless no ground to believe that spontaneous generation concerns only a negligible minority

of creatures, as some scholars have insisted. Hence it is incorrect to suggest, as Balme and others

do, that the spontaneous generation of creatures is a rare and unusual phenomenon. On the

contrary, all evidence shows that biological spontaneous generations is not only regular, but it is

also a common and widespread phenomenon, indeed as common and widespread across living

beings as any one of the ‘many and diverse’ forms of generation of living beings recognized by

Aristotle, ubiquitous among both plants and animals, and present both among blooded and

43

Cfr. Hist. An. V 19, 31 and 32. 44

Hist. An. V 1, 539a 24. 45

Hist. An. V 15, 547b 18-19: “As a general rule (ὅλως), then, all testaceans grow by spontaneous generation in mud

(πάντα τὰ ὀστρακώδη γίνεται ἐν τῇ ἰλύϊ καὶ αὐτόματα).” Cfr. the parallel passage quoted above (Hist. An. V 15, 546b

17-18), and De Gen. An. III 11, 763a 26: “all shellfishes are spontaneously constituted (συνίσταται αὐτόματα πάντα τὰ

ὀστρακόδερμα).” 46

Cfr. De Gen. An. I 16, 720b 6-9: “We cannot be certain about all of shellfishes, but that most of them do not copulate

is plain (τούτων δὲ περὶ μὲν πάντων ἄδηλον, τὰ δὲ πλεῖστα ὅτι οὐ συνδυάζεται φανερόν);” and De Gen. An. III 11 762a

32-35: “The class of land snails is the only class of such creatures that has been seen uniting, but it has never yet been

sufficiently observed whether their generation is the result of the union or not (μόνον δὲ τῶν τοιούτων συνδυαζομένων

ἑώραται τὸ τῶν κοχλιῶν γένος. εἰδ’ ἐκ τοῦ συνδυασμοῦ ἡ γένεσις αὐτῶν ἐστιν ἢ μὴ οὔπω συνῶπται ἱκανῶ).”

18

bloodless creatures. Indeed, in terms of the relative ratio of species of spontaneously generated

creatures to non-spontaneously generated ones, Aristotle’s writings show that spontaneous

generation is more common and widespread as we descend to lower forms of life, and that what can

be considered as an exception among higher animals gradually becomes the norm as we descend to

lower forms of life.

19

4. Spontaneous Generation is Not Contrary to Nature

Some authors have appealed to yet a different sense of the expressions ‘ἀεὶ’ and ‘ὡς ἐπὶ τὸ πολύ’ to

argue that, in a crucial respect, Aristotle’s spontaneous generation indeed occurs ‘παρὰ τὸ ὡς ἐπὶ τὸ

πολύ’. Depew, for instance, claims that “exceptionality, rarity, or irregularity” are not essential

features of what occurs ‘οὔτε ἀεὶ οὔθ’ ὡς ἐπὶ τὸ πολύ’, just as “frequency, statistical normalcy, or

regularity” are not an indication of what comes to be ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’.47

According to

Depew:

‘Always’ refers to an internal connection in a continuous process that moves toward a τέλος. ‘For the

most part’ introduces an ‘escape clause’ or defeasibility condition to internal connectivity that

interprets variations, whether small or large, as impediments to what would otherwise occur.48

Depew claims that although Aristotle’s spontaneously generated creatures cannot be said to be rare

or irregular, yet “they can be said to be exceptional in one important respect: they are defined by

way of privation of concepts that are predicated properly, and hence by priority, of formally

replicating, sexually reproducing substances”.49

According to his interpretation, the expression ‘ὡς

ἐπὶ τὸ πολύ,’ when correctly understood, introduces a ‘defeasibility condition’ to the internal

connectivity of natural processes that interprets phenomena occurring ‘παρὰ τὸ ὡς ἐπὶ τὸ πολύ’ as

“deviations from a properly teleological norm”.50

Dudley, for his part, arrives at the same conclusion by making a similar argument. While

recognizing that Aristotle, in his biological works, holds a theory of regular spontaneous generation

– namely, that “spontaneous generation applies to all members of the class of living beings that are

said to be spontaneously generated”51

– Dudley nonetheless claims that since the regularity that we

witness in spontaneous generations “is a regularity contrary to the regularity of most natural

47

Cfr. DEPEW [2010], p. 289. 48

DEPEW [2010], pp. 289-290. 49

DEPEW [2010], p. 295. 50

DEPEW [2010], p. 290 (italics are mine). 51

DUDLEY [2012], p. 193.

20

generations”,52

we ought to recognize that “spontaneous generation occurs contrary to the norm of

nature”.53

By stressing the fact that spontaneous generation deviates from a natural norm, both Depew

and Dudley make it clear that they identify what occurs ‘παρὰ τὸ ὡς ἐπὶ τὸ πολύ’ with what occurs

‘παρὰ φύσιν’. These authors are clearly right to point out such a use of the expression ‘ὡς ἐπὶ τὸ

πολύ’.54

Indeed, Aristotle often associates what happens ‘for the most part’ with the very ordering

of nature (κατὰ φύσιν), and conversely, what occurs ‘παρὰ τὸ ὡς ἐπὶ τὸ πολύ’ with what is contrary

to the norm of nature (παρὰ φύσιν).55

In this sense, it is correct to say that ‘ὡς ἐπὶ τὸ πολύ’ does not

carry primarily the notion of a statistical ratio, but rather that of a normative standard. And given

this distinction, it seems possible to maintain that despite being a regular and common

phenomenon, there is a sense in which spontaneous generation is not in accordance with nature.

However, Aristotle never claims that spontaneously generated creatures occur παρὰ φύσιν, nor does

he ever treat them as being παρὰ φύσιν. Indeed, there are some major problems with the idea that

spontaneous generation is ‘παρὰ τὸ ὡς ἐπὶ τὸ πολύ’ in this normative sense.

To begin with, Aristotle only uses the expression ‘παρὰ τὸ ὡς ἐπὶ τὸ πολύ’ in the normative

sense of ‘παρὰ φύσιν’ in order to identify anomalous, defective, or abnormal specimens of certain

species.56

He uses this sense of the expression paradigmatically, though not exclusively, to describe

τέρατα, that is, anomalous or ‘monstrous’ specimens of species whose members normally (ὡς ἐπὶ τὸ

πολύ) generate creatures of their own kind. Indeed, in the zoological works, he insists that these

sorts of creatures are “contrary to nature as it holds for the most part (παρὰ φύσιν τὴν ὡς ἐπὶ τὸ

πολύ)”.57

52

DUDLEY [2012], p. 192 (italics are mine). 53

DUDLEY [2012], p. 191 (italics are mine). 54

It is clearly not correct, however, to claim that this is the only sense of the expression ‘ὡς ἐπὶ τὸ πολύ’, as Depew

supposes. 55

Cfr. De Gen. An. IV 4, 770b 9-11; De Gen. An. IV 8, 777a 19-21; De Part. An. III 2, 663b 27-29; Phys. B 8, 198b 34-

36; Eth. Eud. VII 14, 1247a 31-33. 56

Cfr. De Gen. An. IV 3, 767b 5-6 and IV 4, 772a 36-37. 57

De Gen. An. IV 4, 770b 10-11.

21

The mistake that Dudley and Depew make is to improperly assimilate spontaneously

generated creatures with abnormal monstrosities.58

The only place where Aristotle appears to

associate spontaneously generated creatures with imperfect specimens of species whose members

are normally generated from creatures of their own kind is in the well-known passage of De Anima

II 4, in which he mentions that the most natural function of any living being “if perfect and not

defective (ὅσα τέλεια καὶ μὴ πηρώματα) or spontaneously generated (ἢ τὴν γένεσιν αὐτομάτην ἔχει)

is to reproduce another like itself”.59

According to Aristotle, then, creatures that are unable to reproduce other creatures of their

own kind are either imperfect specimens of species whose members normally reproduce creatures

of their own kind, or creatures that owe their existence to spontaneous generation. By stressing the

commonalities between monstrous births and spontaneously generated creatures – namely, the fact

that both are incapable of reproducing, and hence that they are both defined by way of privation of

a certain capacity – Dudley and Depew do raise a significant point. Yet it is equally important to

bear in mind that, according to Aristotle, “privation is spoken of in many ways (ἡ δὲ στέρησις

λέγεται πολλαχῶς), for it means that which does not have a certain capacity (καὶ γὰρ τὸ μὴ ἔχον),

and that which is by nature such as to have it but does not have it (καὶ τὸ πεφυκὸς ἂν μὴ ἔχῃ).”60

This distinction is important as it differentiates between the two meanings of privation,

which these authors seem to conflate. Defective specimens of species whose members normally

reproduce their own kind are incapable of reproducing in the sense that they lack a capacity that

they should have by nature – in the same sense, that is, in which we say that “a blind man is

58

Cfr. DEPEW [2010], pp. 289-290; and DUDLEY [2012], pp. 191-194. The belief that spontaneously generated

creatures are τέρατα, and that monstrous creatures are generated ἀπὸ τοῦ αὐτομάτου has very ancient roots, starting

with Themistius (In Phys. 56.15-17), and followed by Philoponus (In Phys. 269.17-22). This belief is still a widely held

position among Aristotelian scholars, such as TORSTRICK [1875], p. 465, HAMELIN [1931], pp. 137-138,

CHARLTON [1970], pp. 110-111, QUEVEDO [1989], pp. 325-333, QUARANTOTTO [2005], p. 75 ff, and ROSSI

[2011], pp. 266-286. On the other hand, those who oppose the belief that monstrosities are spontaneous events include

CLARK [1934], pp. 31-45, and ROSS [1936], p. 524 Ad Loc. 197b 32-37. 59

De An. II 4, 415a 27-28. 60

Metaph. 1,1046a 31-33. Cfr. also Metaph. 22, 1022b 22-27.

22

deprived of sight”.61

In this sense, monstrous creatures are properly described as deviations from an

inner teleological norm. Indeed, Aristotle characterizes τέρατα as instances of mistakes

(ἁμαρτήματα) occurring in nature, and mistakes, according to Aristotle, arise within processes or

actions that are directed toward the realization of a certain τέλος, but fail to achieve it.62

Spontaneously generated creatures, on the other hand, are incapable of reproducing their

own kind in that they lack a capacity that they are not by nature such as to have, as is the case when

we say that “a plant is deprived of eyes”.63

But this is hardly a deviation from an intrinsic

teleological principle, or the result of an impediment to what would otherwise occur. This explains

why Aristotle never claims that spontaneously generated creatures are παρὰ φύσιν.64

It is also important to stress that Aristotle never uses the expression ‘παρὰ φύσιν’ to describe

entire species of animals, neither when he compares them with the majority of species of their own

kind, nor when he compares them with species belonging to higher and more perfect kinds.

When Aristotle seeks to establish that the majority of species of a certain kind have a typical

characteristic, he always uses the more appropriate expression ‘ἐν τοῖς πλείστοις’, which, in such

contexts, is never associated with a normative standard, unlike the expression ὡς ἐπὶ τὸ πολύ. Such

examples are frequent in Aristotle’s zoology. In the Historia Animalium, for instance, Aristotle

claims that “most fishes (τὰ πλεῖστα) for the most part (ὡς ἐπὶ τὸ πολύ) give birth in the springtime;

while some, as has been said, do so in summer, in autumn, or in winter”.65

In this passage, Aristotle

aims to draw a distinction between the idea that most species of fishes (τὰ πλεῖστα) breed in the

springtime – an empirical, statistical observation with no normative consequence – and the idea that

the members of this species normally (ὡς ἐπὶ τὸ πολύ) breed in the springtime. The use of ὡς ἐπὶ τὸ

πολύ, in this context, refers to a tendency which is internal to each of these species, and which does

61

Metaph. 22, 1022b 24-27. 62

Cfr. Phys. B 8, 199a 33 – 199b 4. 63

Metaph. 22, 1022b 22-24. 64

In fact, as we shall see (Part II, Chapter 2), Aristotle thinks that what would indeed constitute a deviation from the

natural norm, in the case of creatures generated ἀπὸ τοῦ αὐτομάτου, would be the capacity to reproduce other creatures

like themselves. 65

Hist. An. V 11, 543b 18-20.

23

allow us to interpret particular exceptions as deviations from an internal norm. This interpretation

of ὡς ἐπὶ τὸ πολύ is confirmed by the considerations to which Aristotle alludes when he asserts that:

Most of the fishes (οἱ πλεῖστοι τῶν ἰχθύων) breed during the three months between mid-March and

mid-June. A few (ὀλίγοι) breed in autumn, as for example the saupe and the sargus, and such others

of this sort as breed shortly before the autumn equinox; likewise the electric ray and the angel-fish.

Other fishes breed even in winter and in summer, as was previously observed: in wintertime the bass,

the grey mullet, and the pipe-fish; and in summer time, between mid-June and mid-July, the female

tuna, about the time of the summer solstice.66

From these examples, it is evident that when Aristotle speaks of ‘most of the fishes’, he is referring

to species of fishes, and not individual fish – the list of ‘exceptions’, in fact, is a list of species.

These ‘exceptions’, however, are not treated as deviations from a normative standard set at a higher

level of generality – at the level of the γένος – but are simply recorded as statistical and empirical

facts. Aristotle merely states that there are only a few (ὀλίγοι) of them, without drawing any

conclusions about their ‘normality’. The few species of fishes that do not breed during the same

period as the majority of the other species have their own internal autonomy and regularity, and do

not answer to any normative standard external to their own. This is to be expected: according to

Aristotle, the γένος, understood as a generic group of species, does not have a genuine ontological

autonomy that sets it as a normative standard for each of its species, since “no animal exists apart

from the particular species of animal”.67

The very same considerations also apply to the spontaneous generation of living beings.

Aristotle claims that the spontaneous generation of fishes concerns only a few (ὀλίγα) species; but

this observation too is based on a statistical ratio of no normative consequence. Indeed, the point

made about fishes shows that even if spontaneous generation were a rare and uncommon

phenomenon, and even if the regularity of spontaneous generations were ‘a regularity contrary to

the regularity of most natural generations,’ it would not follow that spontaneous generation occurs

‘contrary to the norm of nature.’

66

Hist. An. V 11, 543b 6-12. 67

Metaph. Z 13, 1038b 30-34. Cfr. also Metaph. Z 12, 1038a 5-6.

24

Questions concerning the deviation from a natural norm have meaning only within the

context of each particular species. This is not to say that Aristotle does not also work with what can

properly be regarded as an external criterion of normality, by which he judges entire species as

defective or imperfect. However, when describing an entire class of living beings as defective or

imperfect, Aristotle works with a criterion of normality or perfection provided by ‘higher’ species

of animals; in fact, such an external criterion of normality is determined only by the unique natural

perfection of man, in comparison to which all other species of animals are seen as imperfectly

conformed. This does not mean that all other animals are imperfect within their own species; their

‘malformation’ only has a relative significance, and depends solely upon their comparison to man.68

Finally, the problem with Depew and Dudley’s view that spontaneous generation is ‘παρὰ τὸ

ὡς ἐπὶ τὸ πολύ’ in the sense of being ‘παρὰ φύσιν’ is best illustrated in a passage from Metaphysics

E, in which Aristotle seeks to show that there can be no science of the accidental.

That there is no science of the accidental is obvious; for all science is either of that which is always

or of that which is for the most part (ἢ τοῦ ἀεὶ ἢ τοῦ ὡς ἐπὶ τὸ πολύ). For how else is one to learn or

to teach another? The thing must be determined as occurring either always or for the most part (ἢ τῷ

ἀεὶ ἢ τῷ ὡς ἐπὶ τὸ πολύ), for example, that honey-water is beneficial to a patient in a fever is true for

the most part (ὡς ἐπὶ τὸ πολύ). But science cannot state when that which is contrary to this (τὸ παρὰ

τοῦτο) happens, as for example ‘on the day of new moon’; for then it will be so on the day of new

moon either always or for the most part (ἢ γὰρ ἀεὶ ἢ ὡς ἐπὶ τὸ πολὺ); but the accidental is contrary to

this.69

This argument could be applied in the same way to show that we cannot consider spontaneously

generated creatures as ‘contrary to nature’ on the ground they come to be contrary to the form of

68

Cfr. De Part. An. II 10, 656a 7-12; IV 10, 686b 2-5, 21-23, and 689b 24-28; IV 12, 695a 8-10; De Incessu 4, 706a 19.

As LLOYD [1996], p. 120 has pointed out, Aristotle believes that the paradigmatic instance of natural perfection is

actually represented only by male humans, so that he is prepared to label as ‘deformities’ all sorts of regular biological

phenomena – females, for examples, are often said to be like ‘natural deformities’ because of their inability to concoct

semen. For more on this topic, cfr. VEGETTI [19791-1996

2], pp. 127-197.

69 Metaph. E 2, 1027a 19-26. The importance and the controversial nature of this passage has been noted by many

scholars, both ancient and modern, some of whom have argued that with these remarks, Aristotle implies the view that

there is nothing which is objectively accidental. (Cfr. ROSS [1924], ad loc. p. 361; REALE [2004], ad loc. p. 989;

APOSTLE [1966], Ad Loc. pp. 320-321; and QUEVEDO [1989]). This interpretation of the passage, however, is along

the lines of the argument that Aristotle considers – and rejects – in the Physics, which states that “nothing is the

outcome of chance” since “there is a definite cause of everything which we say comes to be as an outcome of chance or

luck” (Phys. B 4, 196a 1-3). But this is not the point that Aristotle is making in the Metaphysics passage.

25

generation characteristic of most species of animal. What Aristotle is saying in this passage is that if

we can make general statements about the cases that constitute an exception to a broader law, then

the exception would still follow a law of its own and therefore would not be accidental, for ‘it

would be so either always or for the most part’. As we have seen, Aristotle believes that all blooded

animals with only a few exceptions (ἔξω ὀλίγων) always come to be from the seed of an animal of

the same species;70

however, since these exceptions fall into general cases and follow their own

distinct form of regularity – as eels, which always come to be ἀπὸ τοῦ αὐτομάτου – we cannot

conclude that what is contrary to this form of generation (παρὰ τοῦτο) is contrary to nature (παρὰ

φύσιν), for what holds true in those few cases still holds true ‘always or for the most part’.

Hence, it is not the case that spontaneous generation occurs ‘contrary to nature’ despite its

regularity. Indeed, this much can also be considered as a settled point about spontaneous generation

in Aristotle’s biology, namely that it does not occur contrary to nature precisely because it occurs

regularly.

70

Cfr. Part I, Chapter 3.

26

5. Spontaneous Generation is Frequent and Predictable

Another important issue arising from Aristotle’s regular spontaneous generation concerns its

relation to the conditions under which the creatures in question are said to be generated. Balme, for

instance, has claimed that spontaneous generation “occurs when the physical conditions happen to

be right, and so much is random and unpredictable”.71

Echoing his view, Dudley has argued that the

regularity manifested in spontaneous generation is “counterbalanced by the unpredictability of the

place and materials”72

in which different species of spontaneously generated creatures emerge, and

hence concludes that “the occurrence of spontaneous generation […] – at least for Aristotle – is not

fully regular and is unpredictable.”73

Hull, on the other hand, has taken the opposite position. After describing Aristotle’s views

on the spontaneous generation of various kinds of animals, including testaceans, acalephae,

holothurians, sponges and many insects, he observes that:

In the case just cited and in numerous others, the changes occur regularly whenever the appropriate

material is present and the conditions are right. They occur as regularly as ‘rain in winter’ and ‘heat

in the dog-days’.74

Lennox shares the same opinion as Hull, claiming that “many species of organisms are

spontaneously generated with great regularity”.75

Similarly, in criticizing the assumption of those

who take spontaneous generation as “irregular and sporadic”, he points out that “typically

spontaneous outcomes (such as flies) occur with irritating regularity”.76

It is important to note that although these authors employ the term ‘regularity’, their remarks

do not concern the sort of ‘regular spontaneous generation’ that was opposed to ‘random

71

BALME [1962], p. 98. 72

DUDLEY [2012], p. 193. 73

DUDLEY [2012], p. 193 (italics are mine). 74

HULL [1967-1968], p. 247 (italics are mine); cfr. also HULL [1967], p. 315. 75

LENNOX [1982], p. 236 (italics are mine). 76

LENNOX [1982], p. 228.

27

spontaneous generation’ at the outset of this study.77

We can avoid misunderstanding these remarks

if we take into account that there is yet another sense to the expression ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ in

Aristotle, one which makes it clear that the question at issue here is primarily a question concerning

the frequency of spontaneous generation.

This usage of the expression ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ is quite common in Aristotle, and

serves to quantify the frequency of ordered pairs of events. In this sense, the terms ‘ἀεὶ’ and ‘ὡς ἐπὶ

τὸ πολύ’ are employed to formulate what Judson calls ‘judgments of relative or conditional

frequency’, since they necessarily require the reference to a condition with respect to which a

certain event occurs ‘always’ or ‘for the most part.’78

With this meaning of the expression then,

Aristotle associates the adverb ‘ἀεί’ with what happens from necessity (ἐξ ἀνάγκης) given a

determinate event. By contrast, in the Analytics, he uses the expression ὡς ἐπὶ τὸ πολύ to convey the

idea what of is likely (εἰκός) to occur given certain conditions.79

This sense of ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ is ubiquitous in Aristotle and used to describe

phenomena of all kinds.80

Its use recurs in the description of complex and comparatively rare

meteorological and geological events, as when Aristotle claims that “comets appear frequently (ὡς

ἐπὶ τὸ πολύ) during dry and windy seasons”,81

or that “earthquakes occur frequently (ὡς ἐπὶ τὸ

πολύ) in the absence of winds”.82

Yet, as Hull’s passage above suggests, Aristotle often exemplifies

the relative conditions with respect to which certain events are said to occur frequently or

infrequently by referring to common seasonal meteorological phenomena. In the Metaphysics, for

instance, Aristotle claims that “if in the dog-days (ἐπὶ κυνί) there is wintry and cold weather, we say

this is an accident, but not if there is sultry heat (ἀλέα), because the latter is always or for the most

77

Cfr. Part I, Chapter 1. 78

Cfr. JUDSON [1991], p. 83. 79

Cfr. An. Pr. II 27, 70a 4-7; cfr. also Rhet. I 2, 1357a 26-29; in De Gen. An. IV 4, 772a 37, Aristotle claims what

occurs ὡς ἐπὶ τὸ πολύ is ‘εἰωθός (customary)’. 80

For instance, in ethics (cfr. Rhet. II 19, 1393a 4-5), productive sciences (cfr Metaph. E 2, 1027a 23-24), psychology

(cfr. De Mem. 1, 449b 7) and biology (cfr. Hist. An. II 3, 501b 22-24). 81

Meteo. I 7, 344b 26-28. 82

Meteo. II 8, 366a 6-8.

28

part so, but not the former (ὅτι τὸ μὲν ἀεὶ ἢ ὡς ἐπὶ τὸ πολὺ τὸ δ’ οὔ).”83

Similarly, in the Physics, he

says that “we do not think that it is by chance or by coincidence if it rains often (πολλάκις) during

the winter, but if it does so in the dog-days (ἀλλ’ ἐὰν ὑπὸ κύνα); nor if there is heat during the dog-

days (ὑπὸ κύνα), but only if we have it in winter,”84

the reason being, once again, that rain occurs ‘ἢ

ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ in winter just as heat occurs ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ during the dog-days.

If we now look at Aristotle’s observations on spontaneously generated creatures, it is clear

not only that Hull and Lennox are correct in arguing that spontaneous generation occurs with great

frequency, but also that Hull’s analogy with meteorological phenomena is fitting; indeed, Aristotle

consistently applies similar considerations to the particular seasonal and geographical conditions

that favor the spontaneous generation of different species of living beings. For instance, he notes the

following about the so-called ‘froth’ (ὁ καλούμενος ἀφρός) – tiny fish spontaneously generated out

of sand:

These tiny fishes are found in sheltered and marshy regions, when after a spell of fine weather the

ground is getting warmer (ὅταν εὐημερίας γενομένης ἀναθερμαίνηται ἡ γῆ), as, for instance (οἷον),

in the neighborhood of Athens, at Salamis and near the tomb of Themistocles and at Marathon; for in

these places the froth is found. It appears, then, in such places and during such weather (φαίνεται δ’

ἐν μὲν τόποις τοιούτοις καὶ εὐημερίαις τοιαύταις).85

Note that Aristotle’s reference to the particular places in which the ‘froth’ is found does not imply

that its generation is ‘random’ or ‘unpredictable’ as Balme and Dudley claim. In fact, Aristotle

takes the ‘froth’ as the kind of thing that occurs “in such places and during such weather (ἐν τόποις

τοιούτοις καὶ εὐημερίαις τοιαύταις)”, namely the sort of thing that occurs in shaded regions and

during periods of fine weather, which normally “lasts from the autumn rising of Arcturus up to the

spring-time”.86

Indeed, as a “proof (σημεῖον)” of his assertion, Aristotle offers “the fact that in cold

83

Metaph. E 2, 1026b 33-35. 84

Phys. B 8, 199a 1-3. 85

Hist. An. VI 15, 569b 9-22. 86

Hist. An. VI 15, 569b 3-4.

29

weather (ἐὰν μὲν ᾖ ψῦχος) they are not caught, and that they are caught in warm weather (ἐὰν δ’ ᾖ

εὐδία)”.87

When confronting these observations, it is also extremely important to stress the fact that the

same meticulous attention to the particular localities in which spontaneously generated creatures

appear is paid by Aristotle not only to spontaneously generated fish, but to all fish. For instance, at

the end of his extensive survey on the periods of reproduction of all the different species of fishes,

after having shown their great degree of variability and dependence on other external factors such

as location, Aristotle claims that:

In general, we must bear in mind that the same fish, if they are not in the same localities, have not

the same season for pairing, for conception, for parturition, or for flourishing. The so-called

‘coracine’, for instance, in some places spawns about wheat harvest.88

But the periods here presented

tend to approximate what happens for the most part (ἀλλὰ τοῦ ὡς ἐπὶ τὸ πολὺ γινομένου ἐστόχασται

τὰ εἰρημένα).89

In this passage, the use of the verb στοχάζεσθαι indicates that what is qualified as holding ‘ὡς ἐπὶ

τὸ πολύ’, namely the frequency of the correlation between different species of fish and their distinct

periods of reproduction, is the result of a statistical elaboration of empirical data. But this means

that all biological frequencies – whether in spontaneous or sexual generations – are

‘counterbalanced by the unpredictability of the place and materials’ in which different species of

creatures come into being. This, however, does not make spontaneous generation any more

‘random’ or ‘unpredictable’ than sexual generation.

The case of spontaneously generated insects – discussed at great length and in great detail in

Historia Animalium V 19 – provides another clear illustration of the considerable frequency with

which spontaneously generated creatures come into being:

Of insects some are derived from kindred animals (τὰ μὲν ἐκ ζῴων τῶν συγγενῶν) – as the venom-

spider from the venom-spider and the common-spider from the common-spider, and so with the

87

Hist. An. VI 15, 569b 4-6. 88

Whereas it normally spawns in the fall (cfr. Hist. An. VI 17, 570b 22). 89

Hist. An. VI 17, 571a 22-27.

30

locust, the grasshopper, and the cicada – while others are not derived from living parentage, but are

generated spontaneously (τὰ δ’ οὐκ ἐκ ζῴων ἀλλ’ αὐτόματα): some out of dew falling on leaves,

according to nature in the spring (κατὰ φύσιν μὲν ἐν τῷ ἔαρι), but often (πολλάκις) in winter too

when (ὅταν) there has been a stretch of fair weather and southerly winds; others grow in decaying

mud or dung; others in timber, green or dry; some in the hair of animals; some in the flesh of

animals.90

This passage concerning the spontaneous generation of insects, as we shall see, is remarkable in

many different respects.91

For the time being, however, it is sufficient to point out that it settles the

questions of the frequency of spontaneous generation. The spontaneous generation of living beings,

even in this sense of the expression, is clearly a phenomenon that occurs ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ.’ It

is as much a part of the orderly and predictable cycles of generations as the reproduction of living

beings from parents of the same kind, and hence, as Aristotle himself recognizes, it occurs κατὰ

φύσιν – in accordance with nature. From a purely empirical and descriptive point of view, the

cyclical and orderly frequency of the spontaneous generation of insects is no different from that of

other species of insects which, as Aristotle says, naturally copulate and breed in the spring “but

copulate and breed in the winter too, when (ὅταν) the weather is fine and south winds prevail”.92

Thus, upon a careful reading of Historia Animalium, it is at once clear that spontaneous

generation is not an unpredictable, infrequent, or sporadic phenomenon, as some scholars maintain.

In fact, the generation of creatures belonging to species whose members come to be ἀπὸ τοῦ

αὐτομάτου is as frequent, orderly, recurrent, and predictable as the generation of creatures

belonging to species whose members come from the seed of creatures of the same kind. In this

respect too, then, biological spontaneous generation is on a par with the ‘many and diverse’ forms

of generation of living beings by parents of their own kind, which Aristotle treats as paradigmatic

instances of things which are or come to be ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’.

90

Hist. An. V 19, 550b 30 – 551a 6. 91

Cfr. Part I, Chapter 6 and 9. 92

Hist. An. VI 9, 542b 27-29.

31

6. Spontaneous Generation is Causally Uniform

As our research so far has shown, spontaneous generation – just as all of the other ‘many and

diverse’ forms of generation of living beings recognized by Aristotle in his biological works – is a

natural phenomenon that falls within the category of that which occurs ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ in

that it is regular (spontaneously generated creatures belongs to species whose members are always

spontaneously generated); it is frequent (spontaneous generation occurs recurrently during the

appropriate seasons); and it is common (it concerns many species of creatures across all the major

γένη of living beings).

Lennox, however, while he recognizes that these three characteristics are fundamental to

spontaneous generation, nonetheless believes that spontaneous generation occurs ‘οὔτε ἀεὶ οὔθ’ ὡς

ἐπὶ τὸ πολύ’ in another, even more important respect. In his influential article on spontaneous

generation, Lennox writes:

Spontaneous biogenesis is outside what occurs always or usually, notwithstanding the frequency of

spontaneous production. Aristotle’s general account of spontaneous generation is that, where the

result of a process was not its goal, it is not likely always or usually to be produced in the same

manner. Thus, while many species of organisms are spontaneously generated with great regularity,

they do not come to be always or usually due to the same cause.93

Lennox’s hypothesis rests on a careful analysis of Aristotle’s account of τὸ αὐτόματον in the

Physics, and on a criticism of the way in which this text has traditionally been interpreted.

According to Lennox, although in the Physics Aristotle sometimes claims that what comes to be

ἀπὸ τοῦ αὐτομάτου comes to be ‘neither always nor for the most part (οὔτε ἀεὶ οὔθ’ ὡς ἐπὶ

τὸ πολύ)’, we ought to interpret this assertion on the basis of the more precise formulation presented

at the outset of Physics B 5, in which Aristotle states more specifically that what comes to be ἀπὸ

τοῦ αὐτομάτου, comes to be ‘neither always nor for the most part in the same way (οὔτε ἀεὶ οὔθ’ ὡς

93

LENNOX [1982], p. 236 (Lennox’s italics).

32

ἐπὶ τὸ πολύ ὡσαύτως).94

If we give due weight to the key prepositional phrase that qualifies this

claim, says Lennox, we ought to recognize that “there is nothing in such a concept that rules out the

regular occurrence of events”.95

In Lennox’s opinion, the key to understanding this distinctive feature of spontaneous

generation is to consider that τὸ αὐτόματον, according to Aristotle’s account in the Physics, is an

accidental cause (αἴτιον κατὰ συμβεβηκός), and hence that “spontaneous productions occur neither

always of necessity nor usually because incidental causes, by their very nature, cannot produce the

same effects always or usually”.96

What Lennox is suggesting, then, is that we interpret the

expression ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ so as to refer to the causal uniformity of a process. In this sense,

to say that spontaneous generation occurs ‘neither always nor for the most part in the same way’ is

to say that it occurs ‘neither always nor for the most part according to the same causes’. That is, if

something occurs ἀπὸ τοῦ αὐτομάτου, the causes must be different in the different cases of its

occurrence.

By interpreting the expression ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ as Lennox suggests, we understand

why he believes that the lack of causal uniformity does not rule out the regularity of spontaneous

generation. Indeed, spontaneously generated creatures may well belong to species whose members

are always generated without seed; yet, insofar as they are spontaneously generated, these creatures

would not come to be always or for the most part in the same way, that is, according to the same

causes.

In addition, Lennox claims that if something occurs spontaneously, then “there will be an

unlimited number of potential candidates for its actual cause, and the list of possible causes will be

94

Cfr. Phys. B 5, 196b 10-11: “Πρῶτον μὲν οὖν, ἐπειδὴ ὁρῶμεν τὰ μὲν ἀεὶ ὡσαύτως γιγνόμενα τὰ δὲ ὡς ἐπὶ τὸ πολύ,

φανερὸν ὅτι οὐδετέρου τούτων αἰτία ἡ τύχη λέγεται οὐδὲ τὸ ἀπὸ τύχης, οὔτε τοῦ ἐξ ἀνάγκης καὶ αἰεὶ οὔτε τοῦ ὡς ἐπὶ τὸ

πολύ”. We should note, however, that in this passage Aristotle is referring to what is said (λέγεται) about τύχη, not τὸ

αὐτόματον (cfr. Part II, Chapter 7). Similarly, cfr. Eth. Eud. VII 14, 1247a 31-33, the only other place in which Aristotle

uses this expression: “ἀλλὰ μὴν ἥ γε φύσις αἰτία ἢ τοῦ ἀεὶ ὡσαύτως ἢ τοῦ ὡς ἐπὶ τὸ πολύ, ἡ δὲ τύχη τοὐναντίον.” 95

LENNOX [1982], p. 238. 96

LENNOX [1982], p. 233.

33

different in every case in which that result occurs incidentally”,97

which perhaps explains why

spontaneous generation, despite lacking causal uniformity, occurs with great frequency. Hence, on

his view, although animals that come about by spontaneous generation do indeed come into being

regularly and with great frequency – as the biological observations show – the way in which they

come into being, that is, the causal explanation for their coming into existence, is not the same in

all, or most, instances, as it is in generation of creatures from parents of the same kind.

However, despite offering important insight into Aristotle’s account of τὸ αὐτόματον in the

Physics,98

Lennox’s hypothesis does not agree with Aristotle’s account of spontaneity in the

biological works, as Lennox himself has more recently recognized.99

In fact, the analysis of

spontaneous generation in Aristotle’s biological works leaves no room for doubt that spontaneously

generated creatures come to be ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ ὡσαύτως’ in the precise sense of the

expression given by Lennox; namely, they come to be according to the same causes, both with

respect to their sources of movement – the warmth of the wind and the sun – and with respect to

their distinctive material causes, which Aristotle describes in considerable detail.

The passage from the Historia Animalium mentioned in the previous section concerning the

spontaneous generation of insects provides a good starting point to engage in a causal analysis of

spontaneous generation in general. As we have seen, Aristotle claims that spontaneously generated

insects come to be “according to nature in the spring (κατὰ φύσιν μὲν ἐν τῷ ἔαρι), but often in

winter too (πολλάκις δὲ καὶ τοῦ χειμῶνος) when there has been a stretch of fair weather and

southerly winds (ὅταν εὐδία καὶ νοτία γένηται πλείω χρόνον)”.100

Now, if Lennox’s interpretation

of spontaneous generation were correct, then in looking at this passage, we would have to be able to

separate the frequency with which spontaneously generated insects come into being from the causes

by virtue of which they come into being. In other words, we would have to accept as true that

97

LENNOX [1982], p. 232. 98

Cfr. Part II, Chapter 6. 99

LENNOX [2001], p. 226. 100

Hist. An. V 19, 551a 2-4; cfr. Part I, Chapter 5.

34

although insects are frequently generated in the spring and appear often also in the winter, they

nevertheless do not come to be always or for the most part in the same way, namely, by virtue of the

same causes.

Yet, clearly, this is not what Aristotle intended to say, since shortly after describing several

different species of spontaneously generated insects, he claims that for all of them, “the principle of

their generation comes to be from the sun or the wind (ἡ ἀρχὴ γίνεται τῆς γενέσεως ὑφ’ ἡλίου ἢ ὑπὸ

πνεύματος)”.101

The account of the principle of spontaneously generated creatures, which Aristotle

presents in this passage, is consistent with his claim in De Generatione Animalium, where, after

stating that the cause of the generation of animals that come from seed is “the heat in the spermatic

residue (ἡ δὲ θερμότης ἐν τῷ σπερματικῷ περιττώματι)”102

of the male parent, he claims that “for

animals spontaneously generated (τοῖς δὲ αὐτομάτως γιγνομένοις) the cause (αἰτία) is the

movement and heat of the right season of the year (ἡ τῆς ὥρας κίνησις καὶ θερμότης)”. 103

In this

passage, the term ὥρα denotes the appropriate period of time, determined by the orderly revolutions

of the heavenly bodies (κίνησις), which are responsible for the thermal changes (θερμότης) that

cause the spontaneous generation of living creatures.104

Thus, insects are generated according to nature (κατὰ φύσιν) in the spring because of the

thermal conditions characteristic of this season, and are generated often (πολλάκις) in the winter

whenever (ὅταν) those very same conditions happen to be present. The great frequency of the

spontaneous generations of insects, therefore, does not occur despite the lack of causal uniformity,

but precisely by virtue of the underlying causal uniformity. Indeed, what Aristotle wants to show, if

101

Hist. An. V 19, 552a 10-11. For the role of the sun as ἀρχὴ γενέσεως of living beings generated from seed, cfr. Phys.

B 2, 194b 13: “Man is generated by man and by the sun (ἄνθρωπος γὰρ ἄνθρωπον γεννᾷ καὶ ἥλιος)”, and Metaph. 5,

13-17: “the cause (αἴτιον) of man is the elements in man (fire and earth as matter, and the peculiar form), and the

external cause, whatever it is, like the father, and besides these the sun and its oblique course (καὶ παρὰ ταῦτα ὁ ἥλιος

καὶ ὁ λοξὸς κύκλος), which are neither matter nor form nor privation nor of the same species with man, but moving

causes (οὔτε ὕλη ὄντα οὔτ’ εἶδος οὔτε στέρησις οὔτε ὁμοειδὲς ἀλλὰ κινοῦντα)”. For the role of the sun as ἀρχὴ

γενέσεως of spontaneous creatures, cfr. also Hist. An. V 19, 551b 27 – 552a 8: “ἕως ἂν ἥλιος ἢ πνεῦμα κινήσῃ” and

Hist. An. V 19, 552a 20-29: “καὶ κινεῖται πνεύματος ἢ ἡλίου γενομένου.” 102

De Gen. An. II 6, 743a 26-27. 103

De Gen. An. II 6, 743a 35-36. 104

Cfr. the associated passage in Metaph. Z 9, 1034a 25-26, where Aristotle claims that the cause of spontaneous

phenomena is “θερμότης ἡ ἐν τῇ κινήσει”.

35

anything, is that although spontaneously generated insects may appear to be generated during any

‘random season’ – whether spring or winter – there is nonetheless a precise causal regularity, which

provides an explanation for this margin of variation. From the point of view of the principle of

generation, then, it can be said that spontaneously generated creatures come to be ‘always or for the

most part in the same way’, that is, for the same causes.105

Moreover, spontaneously generated creatures can also be said to come to be ‘always or for

the most part in the same way’ when we consider them in relation to their material cause. Although

Aristotle often speaks in broad terms, claiming, for example, that animals arise spontaneously from

mud or decaying matter,106

in other more specific passages, he accurately distinguishes all the

different kinds of matter out of which spontaneous formations come forth. In the passage of

Historia Animalium concerning the generation of insects, for instance, Aristotle mentions a number

of different materials out of which spontaneously generated insects are formed: dew falling on

leaves, decaying mud, dung, green or dry timber, hair or flesh of animals, and excrement.

Even in this case, if Lennox’s interpretation were correct, that is, if spontaneously generated

animals were indeed regularly and frequently generated but not caused to come to be always or for

105

The passage from the Meteorologica mentioned in the previous section concerning the occurrence of earthquakes

offers, once again, an interesting parallel with the generation of insects. According to Aristotle’s theory, the cause

(αἴτιον) of earthquakes is the wind (πνεῦμα), “whenever the external exhalation happens to rush in the interior of the

earth (ὅταν εἴσω τύχῃ ῥυὲν τὸ ἔξω ἀναθυμιώμενον)” (Meteor. II 8, 366a 4-5), which explains why for the most part (ὡς

ἐπὶ τὸ πολύ) earthquakes occur during calm weather (νηνεμίας). However, he also adds immediately thereafter that

there is nothing unreasonable (οὐδὲν ἄλογον) in the fact that some earthquakes happen even when a wind is blowing,

“for we see that sometimes several winds blow simultaneously, so that whenever one of these enters the earth we get an

earthquake attended by wind” (Meteor. II 8, 366a 3-11). The above-quoted passage concerning the spontaneous

generation of insects relies on a similar explanation. Aristotle uses the expression ‘κατὰ φύσιν’ – which, on many

occasions, especially in his zoology, he uses interchangeably with ὡς ἐπὶ τὸ πολύ (cfr. De Gen. An. I 19, 727b 29-30: τὰ

δ’ ὡς ἐπὶ τὸ πολὺ γιγνόμενα μάλιστα κατὰ φύσιν ἐστίν; IV 8, 777a 20-21: τὸ κατὰ φύσιν ἐστὶ τὸ ὡς ἐπὶ τὸ πολύ; De

Part. An. III 2: ἢ γὰρ ἐν τῷ παντὶ ἢ τῷ ὡς ἐπὶ τὸ πολὺ τὸ κατὰ φύσιν ἐστίν) – to say that spontaneous insects are

generated for the most part during the spring; but, although they can also be generated during the winter, we ought not

think that this is because they can be generated by chance or according to different causes. In the Physics, as we have

seen, Aristotle claims that we do not say that it is by chance or by coincidence that there is often (πολλάκις) rain in

winter, but only if there is rain in summer, nor that it is by chance or by coincidence that there are heatwaves in

summer, but only if there are heatwaves in winter (Cfr. Phys. B 8, 198b 36 – 199a 3). It follows that, although Aristotle

may be willing to concede that it is by chance or by coincidence that there is a long stretch of fair weather during winter

– a condition which is contrary to what happens for the most part during this season – he does not think that it is by

chance or coincidence that insects are spontaneously generated also during this season: this, in fact, happens “often

(πολλάκις) […] whenever (ὅταν) there has been a stretch of fair weather and southerly winds”. From the point of view

of the principle of generation, then, it can be said that spontaneously generated creatures come to be ‘always or for the

most part in the same way’, that is, for the same causes. 106

De Gen. An. I 1, 715b 4-5.

36

the most part in the same way, we would expect insects of a determinate kind not to arise always or

for the most part from the same material source. But again, this is not what Aristotle believes.

Although he recognizes that spontaneously generated creatures “in general are found in practically

anything (καὶ ὅλως ἐν πᾶσιν ὡς εἰπεῖν), […] provided they contain the conditions of life (ὅσα ἔχει

αὐτῶν ζωήν)”,107

he nevertheless goes into considerable detail to establish specific correlations

between each species of animals spontaneously generated and the kinds of materials from which

their members arise. Thus, to cite but a few examples among insects, Aristotle claims that

butterflies are generated from caterpillars which grow on cabbage,108

the stag-beetle from grubs

generated in dry wood,109

gnats from ascarids engendered in the slime of wells,110

the tick from

couch-grass,111

the fly from grubs in the dung,112

the horse-fly from timber,113

and the cantharis

from the caterpillars that grow on fig-trees.114

Aristotle presents similar considerations for other kinds of spontaneously generated

creatures; for example, although he claims that “on the whole (ὅλως), all shellfishes are

spontaneously generated in mud (πάντα τὰ ὀστρακώδη γίνεται ἐν τῇ ἰλύϊ καὶ αὐτόματα)”, he also

makes it immediately clear that different types of shellfishes can be distinguished from one another

“according to the different kinds of mud from which they are generated (κατὰ τὴν διαφορὰν τῆς

ἰλύος ἕτερα)”.115

Thus, to cite again but a few examples, Aristotle claims that oysters are generated

in slimy soil,116

cockles in sandy bottoms,117

and limpets in stony grounds.118

The importance of

107

Cfr. Hist. An. V 32, 557b 10-12. 108

Cfr. Hist. An. V 19, 551a 13-16. 109

Cfr. Hist. An. V 19, 551b 16-18. 110

Cfr. Hist. An. V 19, 551b 27-28. 111

Cfr. Hist. An. V 19, 552a 15. 112

Cfr. Hist. An. V 19, 552a 20-29. 113

Cfr. Hist. An. V 19, 552a 29. 114

Cfr. Hist. An. V 19, 552a 31 – 552b 2. The long list of spontaneously generated insects, and their correlative material

causes, continues throughout Hist. An. V 19, 31, and 32. 115

Hist. An. V 15, 547b 18-19. 116

Cfr. Hist. An. V 15, 547b 20. 117

Cfr. Hist. An. V 15, 547b 20-21. 118

Cfr. Hist. An. V 15, 547b 20-21. Cfr. also Hist. An. V 15, 546b 19 - 547b 2 for the purpura; Hist. An. V 15, 547b 3-

11 for the trumpet-shell; Hist. An. V 15, 547b 13-17 for lagoon oysters, clams, razor-fishes, scallops, and pinnas; Hist.

An. V 15, 547b 18-32 for ascidians, barnacles, and nerites; and Hist. An. V 15, 548a 21- 548b 10 for sea-anemones and

sponges.

37

this passage cannot be underestimated, as it shows that Aristotle believes that each of the different

species of shellfish are regularly generated from determinate kinds of material, which reveals that

the regularity – like the frequency – of spontaneous generation occurs not despite the lack of causal

uniformity, but precisely by virtue of the underlying causal uniformity.119

Although spontaneously generated creatures are often described as arising “from

decomposing matter (ἐκ σηπομένης τῆς ὕλης)”,120

in De Generatione Animalium III 11, Aristotle is

eager to clarify that these creatures are not caused to come to be by a process of decomposition

(σῆψις), but by a process of concoction (πέψις), just like creatures that come to be from seed, since

“nothing comes into being by putrefying, but by concocting, and putrefaction and the thing

putrefied is only a residue of that which is concocted”.121

As we have seen, in spontaneous

generation such concoction is the result of the action of the sun, or more generally, of the heavenly

bodies, whose recurrent and orderly motions produce the sort of heat that initiates the generative

process and thereby explain the order, recurrence, and frequency of spontaneous generation. In

addition, by acting on different kinds of material, the generative heat produced by the motion of the

heavenly bodies produces creatures of different sorts according to the different kinds of materials,

whereby it explains not only the frequency but also the regularity of spontaneous generation.122

Hence, we should recognize that the frequency and regularity of spontaneous generations is

grounded in the underlying causal uniformity of these processes. Just as creatures generated from

119

In a footnote to his article, LENNOX [1982], p. 236, claims that “it is unclear how Aristotle might have reacted to

the suggestion that in cases where the identical sort of creature is produced the material conditions must, at some level,

be identical. What is clear is that such an identification would not yield a cause identical in any sense with the result of

the spontaneous process”. Lennox’s point is valid: the fact that the same cause always or for the most part yields to the

same result does not imply that the result of the process is the same – at the formal level – as the cause of the process.

But this very remark shows the very problem with Lennox’s view. The formal identity between the cause and the result

of a process is what paradigmatically characterizes sexual generation – or at any rate generation ἐκ σπέρματος – which

Lennox appropriately refers to as ‘formal replication’; but if so, then it is a truism to claim that when there is no formal

replication, the cause of a process is not identical in any sense with the result of a process. What is not justified,

however, is Lennox’s broader notion that in a process that does not exemplify formal replication, the result “is not likely

always or usually to be produced in the same manner” (ibidem). 120

De Gen. An. I 1, 715b 4-5; cfr. also De Gen. An. I 1, 715b 27-28: “ἐκ τῆς γῆς σηπομένης ἢ μορίων τινῶν ἐν τοῖς

φυτοῖς”; De Gen. An. III 11, 763a 27-28: “ἐκ σηπομένης τῆς ἰλύος”; and Hist. An. V 1, 539a 22-23: “ἐκ γῆς σηπομένης

καὶ φυτῶν”. 121

De Gen. An. III 11, 762a 13-15. 122

LLOYD [1996], p. 117 is right, then, when he says that “by assigning a determinate material cause to these instances

of spontaneously generated animals, Aristotle brings them closer to normal patterns of coming-to-be”.

38

seed come to be ‘always or for the most part in the same way’, because “it is not any random thing

that comes from a particular seed (οὐ γὰρ ὅ τι ἔτυχεν ἐκ τοῦ σπέρματος ἑκάστου γίγνεται), but an

olive-tree comes to be from one sort of seed and a man from another”,123

so too we ought to

acknowledge that creatures generated without seed come to be ‘always or for the most part in the

same way’, for it is not ‘any random thing’ that comes to be from a particular material source. Even

in this particular respect, then, creatures generated ἄνευ σπέρματος are no different from creatures

generated ἐκ σπέρματος.

123

Phys. B 4, 196a 31-33.

39

7. Species of Spontaneously Generated Creatures are Not Eternal

In a noteworthy article on spontaneous generation in Aristotle’s biology, G. E. R. Lloyd has argued

that the most important point emerging from the study of the way in which Aristotle treats

spontaneity in his zoological writings “is that the creatures ‘spontaneously generated’ are regular

kinds”.124

The findings of our investigation so far have lead us to conclude that this statement is

correct, if by ‘regular kinds’ we mean kinds whose members are always generated in the same way.

Indeed, spontaneous generation is as regular, common, frequent, and causally uniform as any of the

other ‘many and diverse’ forms of generation of living beings, and hence, in all of these respects,

creatures that are generated ἄνευ σπέρματος are indistinguishable from creatures that are generated

ἐκ σπέρματος.

There is no denying that Aristotle orders and classifies spontaneously generated creatures

according to determinate species and kinds just as he does with creatures generated from seed.

Thus, to cite but a few examples from passages already considered, Aristotle claims that shellfishes

constitute “the only γένος that almost in its totality” does not reproduce by copulation.125

Similarly,

when speaking of intestinal worms, Aristotle states that “of these worms there are three γένη: one

named the flat-worm, another the round worm, and the third the ascarid”.126

It is important to notice the flexibility of the notion of ‘γένος’, which is used in the former

passage to designate a genus of living beings, and in the latter passage to designate individual

species. This is very common in Aristotle.127

In fact, as Balme has rightly observed, in the

124

LLOYD [1996], p. 105 (Lloyd’s emphasis); cfr. also p. 118. 125

Hist. An. V 15, 546b 17-18 (translation is mine). Cfr. also De Gen. An. I 16, 720b 6-9 and De Gen. An. III 11 762a

32-35. 126

Hist. An. V 19, 551a 8-10. 127

Cfr. also Hist. An. IV 2, 525a 30 – 525b1: “With regard to the crustaceans, one kind (γένος) is that of the crayfish,

and a second, resembling the first, is that of the lobster; the lobster differing from the crayfish in having large claws,

and in a few other respects as well. Another kind is that of the carid, and another is that of the crab, and there are many

species (γένη) both of carid and of crab.”

40

biological works the notions of ‘γένος’ and ‘εἶδος’ are both used with the same flexibility.128

Although Aristotle sometimes claims that the γένος is said ‘of more things (ἐπὶ πλεῖον)’ than the

εἶδος,129

in the biological works these terms are in fact used interchangeably to indicate a generic

‘group’ or ‘class’ of things sharing a common trait at any level of generality.130

The only difference

between the use of ‘γένος’ and ‘εἶδος’ in Aristotle’s zoology, is that whereas the term ‘γένος’ is

only used to indicate a group of things, the term ‘εἶδος’ is sometimes also used in its original

meaning of ‘form’ or ‘shape’ to indicate the visible appearance of a thing, that is, its morphological

structure.131

To shed light on the importance of this meaning of the term ‘εἶδος’ to our discussion

on spontaneously generated creatures, it might be helpful to reconsider the passage of the Historia

Animalium in which Aristotle introduces the concept of spontaneous generation:

Now there is one property that animals are found to have in common (κοινὸν) with plants. For some

plants are generated from the seed of other plants, whereas other plants are spontaneously generated

(τὰ δ’ αὐτόματα γίνεται) through the formation of some principle similar to a seed; and of these

some derive their nutriment from the ground, whereas others grow inside other plants, as is

mentioned in the treatise on Plants. In the same way, among animals, some are generated from

animals according to the kinship of the form (τὰ μὲν ἀπὸ ζῴων γίνεται κατὰ συγγένειαν τῆς μορφῆς),

whereas others grow spontaneously and not from kindred animals (τὰ δ’ αὐτόματα καὶ οὐκ ἀπὸ

συγγενῶν); and of these some come from putrefying earth or vegetable matter, as is the case with a

number of insects, while others are spontaneously generated in the inside of animals out of the

secretions of their several organs. In animals where generation takes place from kindred animals

(ἀπὸ συγγενῶν ζῴων), wherever there is duality of sex generation is due to copulation. Among

fishes, however, there are some that are neither male nor female, and these, while they are identical

in kind with other fish (τῷ γένει μὲν τὰ αὐτά), they differ from them in species (τῷ εἴδει δ’ ἕτερα).132

What Aristotle is saying at the end of this passage is that within certain general kinds of fishes, there

are particular species whose members are spontaneously generated, and he describes these as being

distinct from other species of the same γένος in their morphological aspect (τῷ εἴδει δ’ ἕτερα), that

is, in their lack of sexual dimorphism. In this context, the term ‘εἶδος’ clearly refers to the visible

128

Cfr. BALME [1962a]. 129

Cfr. Cat. I 5, 3b 21-23: “ἐπὶ πλεῖον δὲ τῷ γένει ἢ τῷ εἴδει τὸν ἀφορισμὸν ποιεῖται· ὁ γὰρ ζῷον εἰπὼν ἐπὶ πλεῖον

περιλαμβάνει ἢ ὁ τὸν ἄνθρωπον.” 130

Cfr. BALME [1962a], pp. 86-88. Cfr. also VEGETTI [1971], pp. 109-111. 131

Cfr. BALME [1962a], p. 87 and VEGETTI [1971], p. 110. On ‘γένος’ (‘kind’) and ‘εἶδος’ (‘shape’ or ‘form’) cfr.

also PECK [1965], pp. lxiv ff. 132

Hist. An. V 1, 539a 15-29.

41

somatic trait of spontaneously generated fishes. This specific use of the term is confirmed by his

earlier remark concerning sexual generation, namely, that animals are generated from other animals

‘according to the kinship of the form (κατὰ συγγένειαν τῆς μορφῆς)’. Here, the term ‘μορφή’ refers

to the visible somatic structure of animals, which is identically repeated in each individual animal

that comes to be from the seed of another animal.

It is clear, therefore, that Aristotle believes that spontaneously generated creatures can be

distinguished by their identical common morphological traits, and hence classified according to

determinate species and kinds just as creatures generated from seed. In fact, this is what we should

expect given that spontaneous generation is as regular as any other form of generation. However,

when Lloyd claims that spontaneously generated creatures are members of ‘regular kinds’, he does

not simply mean that they belong to species whose members are always spontaneously generated,

but rather that they are members of ‘eternal species’. In other words, Lloyd takes the regularity of

spontaneously generated creatures as evidence that Aristotle believes in the eternity of their species.

On his view, in fact, the forms of spontaneously generated creatures “can still be said to pre-exist –

indeed they are eternal – for Aristotle no doubt believed that there have always been the creatures in

question”.133

In much the same vein, Hull too believes that the fact that generation ἀπὸ τοῦ αὐτομάτου

occurs as regularly as generation ἀπὸ συγγενῶν ζῴων entails that species of animals spontaneously

generated are just as eternal as species of animals reproduced from parents of the same kind.

According to Hull:

There are always horses because horses generally give rise to other horses. But there are also always

eels, although eels never give rise to other eels. Lower species of animals, both as essences and as

classes of organisms, are just as eternal as other species.134

133

LLOYD [1996], p. 122 (Lloyd’s emphasis). 134

LLOYD [1996], p. 122.

42

However, it is a fallacy to infer the eternity of species whose members are spontaneously generated

from the regularity with which members of these species come into being. In other words, the fact

that spontaneously generated creatures belong to species whose members are always (ἀεί)

spontaneously generated does not mean that the creatures in question exist always in the sense

assumed by Lloyd and Hull – in the sense, that is, that would make them belong to eternal species

(ἀΐδιος). To understand why Hull and Lloyd’s position ought to be rejected, it is useful to consider

the crucial passage of De Generatione Animalium in which Aristotle raises the point about the

eternity of the species of living beings whose members are reproduced from creatures of their own

kind:

These, then, are the causes of the generation of animals (διὰ ταύτας τὰς αἰτίας γένεσις ζῴων ἐστίν).

For since it is impossible that the nature of such a class of things should be eternal (ἐπεὶ γὰρ

ἀδύνατος ἡ φύσις τοῦ τοιούτου γένους ἀΐδιος εἶναι), therefore that which comes into being is eternal

in the only way possible (καθ’ ὃν ἐνδέχεται τρόπον, κατὰ τοῦτόν ἐστιν ἀΐδιον τὸ γιγνόμενον). Now it

is impossible for it to be eternal as an individual (ἀριθμῷ μὲν οὖν ἀδύνατον) – for the substance of

the things that are is in the particular; and if it were such it would be eternal – but it is possible in

form (εἴδει δ’ ἐνδέχεται). This is why there is always a γένος of men and animals and plants (διὸ

γένος ἀεὶ ἀνθρώπων καὶ ζῴων ἐστὶ καὶ φυτῶν).135

There is no doubt that this passage, which Aristotle includes at the beginning of the second book of

De Generatione Animalium, focuses exclusively on the generation of living beings ἐκ σπέρματος,

since the study of the spontaneous generation of living things “from a certain earthy and humid

coagulation (ἔκ τινος συστάσεως γεοειδοῦς καὶ ὑγρᾶς)”,136

which he mentions at the end of the first

book in connection with the generation of shellfishes, is postponed “for later discussion (ἀλλὰ περὶ

μὲν τῆς τούτων γενέσεως ὕστερον λεκτέον),”137

until the end of the third book. In addition, the

‘causes (αἰτίαι)’ of the generation of animals referred to at the beginning of this passage are the

male and female principles (ἀρχαί) of generation, which, as we shall see, Aristotle believes to be

135

De Gen. An. II 1, 731b 31 – 732a 1. 136

De Gen. An. I 23, 731b 12-13. 137

De Gen. An. I 23, 731b 13-14.

43

present in all species of living beings that reproduce themselves ἐκ σπέρματος, whether they present

sexual dimorphism or not.138

It is noteworthy that, in this passage, Aristotle uses the term ‘γένος’ twice. In the first

instance, in which Aristotle claims that ‘it is impossible that the nature of such a γένος should be

eternal,’ he is referring to the γένος of things that come to be and pass away – things, that is, that

“admit of both being and not being (ἐνδεχόμενα καὶ εἶναι καὶ μὴ εἶναι)”.139

It is clear that in this

case, ‘γένος’ is used in its generic sense of a ‘group’ or ‘class’ of things that share a common trait,

and that in this sense things that come to be and pass away cannot constitute an eternal γένος, for, as

Aristotle remarks, it is impossible (ἀδύνατος) for the nature (ἡ φύσις) of such a class (τοῦ τοιούτου

γένους) to be eternal (ἀΐδιος). Yet, Aristotle adds that it is nonetheless possible (ἐνδέχεται), in a

way (τρόπον), for things that come to be and pass away to be eternal, namely, by reproducing other

creatures of their own kind so as to be eternal in form (εἴδει); and that, he claims, is why ‘there is

always a γένος of men and animals and plants (γένος ἀεὶ ἀνθρώπων καὶ ζῴων ἐστὶ καὶ φυτῶν)’. It is

important to note that in this second instance, the term ‘γένος’ is not used in the generic sense of a

‘group’ or ‘class’ of things sharing a common attribute, but rather in a more specific sense, which

Aristotle defines in Metaphysics 28, at the beginning of a list of the different senses of ‘γένος’.

There, Aristotle claims that:

The term γένος is used, in a sense, for the continuous generation of things which have the same form

(ἡ γένεσις συνεχὴς τῶν τὸ εἶδος ἐχόντων τὸ αὐτό); for example when we say ‘as long as the γένος of

men lasts (ἕως ἂν ἀνθρώπων γένος ᾖ)’ we mean ‘as long as the generation of them goes on

continuously (ἕως ἂν ᾖ ἡ γένεσις συνεχὴς αὐτῶν).140

A few lines later, Aristotle summarizes this sense by saying that ‘γένος’ is used “in reference to

continuous generation of the same form (τὸ κατὰ γένεσιν συνεχῆ τοῦ αὐτοῦ εἴδους).”141

In a crucial

sense of the term, then, spontaneously generated creatures do not belong to γένη in the same sense 138

Cfr. Part I, Chapter 8. 139

De Gen. An. II 1, 731b 31 – 732a 1. 140

Metaph. 28, 1024a 29-31. 141

Metaph. 28, 1024b 6-7.

44

in which creatures generated from the seed of animals of the same species do, since the generation

of spontaneous creatures is not continuous but rather discrete and episodic. Hence, it is not correct

to say that just as ‘there is always a γένος of men’, in the same way ‘there is always a γένος of eels’,

as Hull suggests, for to say that there is always a γένος of men means that there is a continuous

generation of creatures that are one in form, and this is precisely what does not occur in the case of

spontaneous generation. Nor is it correct to say that spontaneously generated creatures form ‘regular

kinds’ in the sense described by Lloyd, that is, that they are ‘eternal species’, for the regularity with

which the creatures of a certain species come to be is not sufficient to make the species to which

those creatures belong eternal. What is required for a γένος of living beings to be eternal in form is

not just a regular generation, but a continuous generation of things of the same form, which can

only be guaranteed when a creature is capable of generating another creature of the same kind.

Hence, insofar as spontaneous generation is as regular as any other form of generation,

Aristotle can order and classify spontaneously generated creatures according to regular εἴδη and

γένη just as he does with creatures generated from parents of the same kind. However, the fact that

species of spontaneously generated creatures are just as regular as species of animals that reproduce

their own kind does not imply that they are also just as eternal as species of animals that reproduce

their own kind, and in this crucial respect, spontaneously generated creatures do not belong to the

same sort of εἴδη and γένη to which creatures generated from parents of the same kind belong.

45

8. Spontaneous Generation is Not Reducible to Ordinary Causal Analysis

The disambiguation of the term ‘regular’ and the distinction between ‘regular kinds’ and ‘eternal

kinds’ kinds drawn in the previous section are crucial to resolve two of the most critical problems

concerning spontaneous generation. The first relates to the role of formal and final causes in the

account of spontaneous generation.

As we have seen in our discussion of causal uniformity, Aristotle considers spontaneous

generation, just as any other form of generation, to be the product of a process of concoction

(πέψις). 142

In particular, he believes that spontaneous generation is the result of the action of the sun

(ὑφ’ ἡλίου), or more generally the heavenly bodies, whose natural revolution (κίνησις) produce the

heat (θερμότης) that causes generative motions in the appropriate materials.143

This process appears

to be accounted for only by two kinds of causes: the efficient cause, namely the sun, which Aristotle

identifies as the ‘cause (αἰτία)’ and ‘principle of the generation (ἀρχὴ τῆς γενέσεως)’144

of

spontaneous creatures; and the material cause, namely the different materials out of which

spontaneous creatures develop.

Some authors maintain that the peculiarity of spontaneous generation lies precisely in the

absence of formal and final causes. Hull, for instance, claims that in spontaneous generation formal

and final causes are “superfluous”.145

Lennox, for his part, argues that the absence of formal-final

causality is “the fundamental criterion of spontaneity”.146

In particular, he asserts that “two of

Aristotle’s four types of causal explanations will not be appropriate”147

in the case of spontaneous

generation because “explanations in terms of a form as the end for the sake of which a process is

142

Cfr. Part I, Chapter 6. 143

Cfr. De Gen. An. II 6, 743a 35-36. 144

Hist. An. V 19, 552a 10-11; cfr. also Hist. An. V 19, 551b 27 – 552a 8 and Hist. An. V 19, 552a 20-29. 145

HULL [1967-1968], p. 245. 146

LENNOX [1982], p. 238; cfr. also LENNOX [2009], p. 379. 147

LENNOX [1982], p. 225; cfr. also LENNOX [2009], p. 362.

46

taking place are applicable only where that end product is identical in form with the efficient cause

of generation.148

However, other authors, most notably Lloyd, have taken the opposite view and insist that in

the spontaneous generation of living beings, just as in the generation of living beings from seed,

“we can see that there is a role for all four causes”.149

Johnson, who endorses Lloyd’s analysis,

argues, too, that “it is possible to give a complete ‘four’ causal analysis for spontaneously generated

organisms”.150

Lloyd’s examination of spontaneous generation, along with his integrative study of the

kindred phenomenon of metamorphosis, is arguably one of the most insightful studies written on

the topic. However, upon a critical analysis of his arguments, it becomes clear that his conclusion

ought to be rejected, as none of his arguments provide support for his view that spontaneous

generation is accounted for by Aristotle’s ordinary four-fold causal analysis. He presents two

distinct arguments to make his case: one which relies on the idea that spontaneously generated

creatures form ‘regular kinds’, and another, which depends on the role of male and female

principles in spontaneous generation.

In his first argument, Lloyd claims that in spontaneous generation, “there are final causes –

the creatures produced, which, insofar as they form regular species of animals, as they do, also

represent […] the formal causes”.151

There are two errors in this argument. The first lies in Lloyd’s

identification of the ‘final causes’ with ‘the creatures produced’, that is, in his failure to distinguish

the goal of a process from its result or outcome, which is tantamount to failing to distinguish a

cause from that of which the cause is a cause. This is the same sort of confusion as that which

occurs in obliterating the difference between the form of a living being (or of an artifact), and the

individual compound of form and matter – the living being (or the artifact) itself. The form, in fact,

148

LENNOX [1982], p. 228 (italics are mine). 149

LLOYD [1996], p. 122. 150

JOHNSON [2012], p. 135. 151

LLOYD [1996], p. 122 (italics are mine).

47

is the cause of the process of generation or production of the compound, and it is not itself

generated or produced. The compound, on the other hand, is that which is generated and caused; it

is the result or outcome of the process of generation, and as such it is posterior to the cause.152

The

goal of a process of generation, according to Aristotle, is not τὸ γιγνόμενον, which is the outcome

of the process, but τὸ εἶδος τοῦ γιγνομένου, which is the form of such outcome.

The second and more crucial error in Lloyd’s argument lies in his equivocal use of the term

‘regular’. This argument rests on Lloyd’s idea that by ‘regularizing’ spontaneous generation,

Aristotle brings spontaneously generated creatures into line with ‘ordinary kinds’ of living

beings,153

and since the coming into being of creatures belonging to ordinary kinds requires formal

and final causes,154

then spontaneous generation, too, requires formal and final causes. However,

although spontaneously generated creatures do form regular kinds (if by ‘regular kinds’ we mean

species whose members come to be always in the same way); and although in this respect

spontaneous generation is indistinguishable from the many and diverse forms of generation proper

of ordinary kinds (if by ‘ordinary kinds’ we mean, as Lloyd does, species whose members are

always generated from parents of the same kind) what Lloyd nonetheless means to say here is that

spontaneously generated creatures, like creatures belonging to ordinary kinds, form eternal species,

for he believes that in spontaneously generated creatures, “the forms can still be said to pre-exist –

indeed they are eternal – for Aristotle no doubt believed that there have always been the creatures in

question”.155

Yet, as we have seen, this is not the case;156

hence, his argument is based on an

equivocation and is, therefore, invalid. Although we should accept Lloyd’s claim that the coming

152

The identification of the goal of a process with its result is widespread in literature on Aristotle. Thus, for example,

LENNOX [1982] claims that “Aristotle insists that sexually initiated biogenesis is for the sake of its outcome” (p. 221),

and again, that teleological explanations are “explanations of processes by means of their outcomes” (p. 223). Yet, in

this respect, Aristotle is precise in identifying the τέλος with the εἶδος: cfr. for example Phys. B 7, 198a 25-26 - τὸ μὲν

γὰρ τί ἐστι καὶ τὸ οὗ ἕνεκα ἕν ἐστι; and also Phys. B 7, 198b 3-4, where Aristotle claims that ‘the what it is and the

form’ is a cause of motion which is nevertheless not itself subject to motion ‘for it is the goal and that for the sake of

which (τέλος γὰρ καὶ οὗ ἕνεκα)’. 153

Cfr. LLOYD [1996], 117. 154

Cfr. LLOYD [1996], p. 105. 155

LLOYD [1996], p. 122. 156

Cfr. Part I, Chapter 7.

48

into being of creatures belonging to eternal kinds requires formal and final causes, since

spontaneously generated creatures do not belong to eternal kinds, it does not follow that their

generation, too, requires formal and final causes

This objection rests on the pivotal idea that ordinary kinds of living beings require formal

and final causes because they are eternal, not because they are regular. As we have seen, a species

of living beings is eternal only if there is a continuous generation of creatures of the same form,

which occurs only if the result of the process of generation is identical in form with the efficient

cause of generation. To be sure, Lloyd recognizes that the “anomaly” of spontaneously generated

creatures is that their form “does not also serve as the efficient cause (as male parents do)”;157

yet,

he insists that the only difference between spontaneous generation and the generation from parents

of the same kind lies not in the absence of formal causes, but rather “in the way these causes

work”.158

However, if the forms of spontaneously generated creatures do not also serve as efficient

causes, as they do in the generation of living beings from parents of the same kind, then they can

hardly be taken to be causes of generation. Nor is the argument rescued by pointing out, as Johnson

does, that the form of spontaneously generated creatures is “largely determined by the matter”,159

for insofar as the form is determined by matter, it cannot be taken to be a cause. In fact, the very

recognition that the form of spontaneously generated creatures is determined by their matter only

reinforces the conclusion that the causal uniformity of the material causes of spontaneous

generation is sufficient to account for its regularity.

In his second argument, Lloyd relies on the similarities between spontaneously generated

creatures and plants to claim that in spontaneous generation formal and final causes are not absent,

but only less distinct than in the ideal and paradigmatic cases of generation. This argument is based

on the fact that spontaneously generated creatures, just like plants, display no sexual dimorphism –

157

LLOYD [1996], p. 122. 158

LLOYD [1996], p. 122. 159

JOHNSON [2012], p. 137.

49

that is, no distinction between male and female. Lloyd correctly points out that the lack of sexual

dimorphism in plants signals a departure from the ideal and paradigmatic species of living beings,

in which the male and female are separated and given distinct roles, and hence, is a sign of the

lower position of such forms of life in the natural order. But Lloyd continues by claiming that such

a lower position in the natural order is not determined by the absence of formal and final causes, but

only by the fact that formal and final causes are not separated from material causes, and hence, are

less distinct. If that is the case, says Lloyd, then we ought to draw the same conclusions about

spontaneous generation, that is, that “spontaneous generation represents a further departure from the

ideal. The fact that mud can produce testacea can be seen as a further, indeed extreme case, of the

non-differentiation of roles.”160

However, although the similarity between spontaneously generated creatures and plants that

is mentioned by Lloyd finds evidence in the morphological treatment of sexual dimorphism in the

Historia Animalium, the causal analysis of the male and female principles developed in De

Generatione Animalium, which is most relevant to Lloyd’s argument, leads us to reject his

conclusion.

In the Historia Animalium, the general distinction between male and female is presented in

purely empirical terms and is taken as the basis of a simple dichotomous schema whereby Aristotle

distinguishes animals that present sexual dimorphism from animals that lack this trait.

Of the rest, many have, besides the parts above-mentioned, a part for the emission of the sperm (τὸ

σπέρμα); and of animals capable of generation one emits into another, and the other into itself. The

latter is termed ‘female’, and the former ‘male’; but some animals have neither male nor female.

Consequently, the parts connected with this function differ in form (καὶ τῶν μορίων τῶν πρὸς τὴν

δημιουργίαν ταύτην διαφέρει τὸ εἶδος); for some animals have a womb and others an organ

analogous thereto.161

Note that in this passage the term εἶδος is used in the original sense of ‘visible form’ to indicate the

morphological differences between the sexual organs (τὸ εἶδος τῶν μορίων) of male and female

160

LLOYD [1996], p. 123. 161

Hist. An. I 3, 489a 8-15.

50

specimens.162

More importantly, the simple empirical and dichotomous distinction between

creatures that have both male and female and creatures that have neither male nor female leads

Aristotle to include in the same group both creatures that are capable of reproducing their own kind,

like many plants, and creatures that are not capable of reproducing their own kind, namely those

that are spontaneously generated. Hence, in Historia Animalium IV 11, Aristotle claims that among

shellfishes, “just as among plants (ὥσπερ ἐν φυτοῖς),”163

there is no duality of sex, and at the

beginning of that same chapter he states that the absence of males and females in any given species

does not so much imply the incapacity to generate (γεννᾶν), but rather, and more appropriately, the

incapacity to bear young (τίκτειν) and to be pregnant (κύειν).164

In De Generatione Animalium, on the other hand, the distinction between male and female

is the object of long and complex discussions, and is presented in causal terms. It is well known

that, in this treatise, Aristotle claims that in all animals in which the male and female are distinct,

“what the male contributes to generation is the form (εἶδος) and the efficient cause, while the

female contributes the material (τὴν ὕλην)”.165

Aristotle often reiterates the point made in Historia

Animalium that sexual dimorphism is not present in all species of living beings. However, given the

role of the male and the female as causes of generation, he does not deny the presence of male and

female principles among creatures – such as plants which come to be ἐκ σπέρματος – which lack

sexual dimorphism. What he claims, instead, is that in such cases the two principles are present yet

not separated.

In all animals which can move about, the male and the female are separated (κεχώρισται τὸ θῆλυ τοῦ

ἄρρενος), one individual being male and one female, though both are the same in species, as with

man and horse. But in plants these powers are mingled (ἐν δὲ τοῖς φυτοῖς μεμιγμέναι αὗται αἱ

162

Note too that here Aristotle holds the view that both male and females are capable of emitting sperm, and does not

distinguish their roles in causal terms. In De Generatione Animalium, Aristotle holds a different doctrine, denying the

capacity of sperm emission in females. In this passage, Aristotle is closer to the genetic theory of Chapter VII in the

Hippocratic De Genitura. This change of doctrine is not important for our present purposes. 163

Cfr. Hist. An. IV 11, 538b 31. 164

Cfr. Hist. An. IV 11, 538b 22-25. 165

De Gen. An. I 20, 729a 9-11; cfr. also I 22, 730b 14-15, IV 1, 766a 18-21, IV 4, 770b 16-17.

51

δυνάμεις εἰσί), and the female is not separated from the male (καὶ οὐ κεχώρισται τὸ θῆλυ τοῦ

ἄρρενος).166

In the theoretical framework of De Generatione Animalium, the morphological distinction between

species that have the male and the female and species that do not is invalidated but reconstructed

according to causal criteria. The male and the female principles are now seen to be present in all

living beings which are capable of reproducing their own kind, whether or not they manifest sexual

dimorphism. In this way, then, Aristotle comes to include under the same causal paradigm both

creatures that present sexual dimorphism and creatures that do not, as long as they are capable of

reproducing their own kind, and to exclude from it creatures that are incapable of reproducing their

own kind such as spontaneously generated creatures.167

Therefore, despite their common lack of

sexual dimorphism, spontaneously generated creatures, unlike plants that reproduce ἐκ σπέρματος,

do not have the male and female principles precisely because they are incapable of reproducing

their own kind.168

We should therefore reject Lloyd’s opinion that spontaneously generated creatures represent

a further case of non-differentiation of male and female principles, and instead recognize that

Aristotle allows spontaneously generated creatures to have male and female principles, if at all, only

in a metaphorical sense. Studies on spontaneous generation in Aristotle have hardly paid attention

to the fact that the causal structure for the explanation of spontaneously generated creatures in terms

of the action of the sun and other heavenly bodies on earthly materials rests on the adaptation of a

traditional religious belief reported in the first book of De Generatione Animalium, in which

Aristotle tells us that “men think of the earth as female and a mother, but address heaven and the

sun and other like entities as progenitors and fathers”.169

The belief reported by Aristotle about the

heaven and the earth, which invokes the Theogonic myth of the primordial couple Γαῖα and

166

De Gen. An. I 23, 730b 33 – 731a 14. Cfr. also De Gen. An. III 11, 762b 9-11. 167

Cfr. De Gen. An. II 1, 731b 31 – 732a 11. 168

Cfr. De Gen. An. III 11, 762a 35 - 762b 6. 169

De Gen. An. I 2, 716a 15-17.

52

Οὐρανός presented in Hesiod, while identifying quite literally the two basic principles of

spontaneous generation, also assigns to them the metaphorical role of ‘mother’ and ‘father’.170

There is therefore no ground for the belief that spontaneous generation can be reduced to

Aristotle’s ordinary four-fold causal analysis. In the Physics, Aristotle claims that “a man is

generated by man and by the sun (ἄνθρωπος γὰρ ἄνθρωπον γεννᾷ καὶ ἥλιος)”,171

and likewise in the

Metaphysics, he argues that the causes of the generation of a man are the father and “the sun and its

oblique course (καὶ παρὰ ταῦτα ὁ ἥλιος καὶ ὁ λοξὸς κύκλος), which are neither matter nor form nor

privation nor of the same species with man, but moving causes (οὔτε ὕλη ὄντα οὔτ’ εἶδος οὔτε

στέρησις οὔτε ὁμοειδὲς ἀλλὰ κινοῦντα)”.172

Spontaneously generated creatures, by contrast, are

ultimately generated only by the action of the sun and the other heavenly bodies over matter, and it

is precisely the absence of a principle of generation identical in form with the creature generated

that accounts for the fact that spontaneous generation is explained only in terms of material and

efficient causes. If, as it is, what distinguishes spontaneously generated creatures (τὰ αὐτόματα) is

that they come to be not from parents of the same kind (οὐκ ἀπὸ συγγενῶν),173

then we should

agree with Lennox that the absence of formal and final causality is the distinctive aspect of

spontaneous generation.

170

On this passage cfr. VEGETTI [2007], pp. 157-158. 171

Phys. B 2, 194b 13. 172

Metaph. 5, 1071a 13-17. 173

Cfr. Hist. An. V 1, 539a 15-25.

53

9. Spontaneous Generation Occurs κατὰ φύσιν, not φύσει.

The aspects of spontaneous generation brought to light in the previous two sections of this analysis

– namely, that spontaneously generated creatures do not form eternal species and that spontaneous

generation is accounted for only in terms of material and efficient causes – have important

implications when it comes to considering some of the metaphysical implications of this

phenomenon. Lloyd, for instance, has argued that “one thing that emerges from this study of

Aristotle’s treatment of spontaneous generation […] is the robustness of his views on nature”.174

What Lloyd means to say is that Aristotle is able to ‘regularize’ spontaneously generated creatures –

that is, on his view, to make species of spontaneously generated creatures eternal and reducible to

Aristotle’s ordinary four-fold causal analysis – on the basis of his core concept of φύσις, thereby

turning some of the problems raised by spontaneous generation to his own advantage so as to

confirm and reinforce the most fundamental metaphysical tenets of his philosophy. According to

Lloyd, “this is an instance where his leading idea, the concept of nature itself, is not so much

modified, let alone undermined, as confirmed”.175

However, Lloyd’s view that Aristotle’s ‘robust’ sense of nature grounds the regularity of

spontaneous generation ought to be rejected, along with the beliefs on which such a view rests,

namely that species of spontaneously generated creatures are eternal and reducible to Aristotle’s

ordinary four-fold causal analysis. Spontaneously generated creatures, in fact, do not have a φύσις

in the proper or ‘robust’ sense of the term. Rather, when applied to spontaneously generated

creatures, the term φύσις is used only in an improper sense, that is, in a way that is not compatible

with the way in which it is used to describe living beings belonging to species whose members

reproduce their own kind.

174

LLOYD [1996], p. 124 (italics are mine). 175

LLOYD [1996], p. 125.

54

This point can be appreciated if we consider Aristotle’s statement that ‘a man generates a

man,’ which aims at illustrating precisely what it means for something to have a φύσις, that is, an

internal – specifically internal – source of constitution.176

To have a φύσις in this proper and

‘robust’ sense, according to Aristotle, is what makes some living beings – namely, living beings that

are capable of reproducing their own kind – paradigmatic cases of substances: οὐσία, in fact, is

primarily that which is capable of existing in virtue of itself, and the capacity of some living beings

for perpetuating their own form provides a paradigm case of substantiality. For that very same

reason, Aristotle does not think that artifacts have a nature, nor does he think that they qualify as

substances, as is made clear by his remark that “man is born from man, but not bed from bed”.177

But if the incapacity of reproducing their own form is what deprives artifacts of a φύσις, then we

should, for the same reason, conclude that spontaneously generated creatures lack a proper φύσις,

for a horsefly is not born from a horsefly either. Hence to attribute φύσις in a ‘robust’ Aristotelian

sense to spontaneously generated creatures, as Lloyd does, is as improper as it is for Antiphon to

speak of the ‘φύσις’ of a bed.

This conclusion is confirmed by Aristotle’s use of the term ‘φύσις’ in relation to

spontaneously generated creatures in his biological works. As we have seen, in the only two

occasions in these works where Aristotle speaks of the ‘φύσις’ of spontaneously generated

creatures, he does so by using an oxymoronic expression, that is, by qualifying it as a ‘spontaneous

nature’.178

In one instance, Aristotle uses the expression ‘ἡ φύσις αὐτόματος’ to refer to the peculiar

constitution of shellfishes,179

and in the other, he contrasts the ‘φύσις αὐτοματιζούση’ of some

plants with the nature of those which come to be ἐκ σπέρματος.180

Such qualifications seems to

stress the fact that spontaneously generated creatures are biological entities of a peculiar ‘nature’,

176

Cfr. especially Phys. B 1 and Metaph. 3. 177

Phys. B 1, 193b 8-9. For a defense of the view that artifacts are not substances, cfr. KATAYAMA [1999] and

[2008]. 178

Cfr. Part I, Chapter 2. 179

De Gen. An. III 11, 761b 23-24. 180

De Gen. An. I 1, 715b 26-27.

55

and that a proper explanation of the regularity and order of their coming into being ought to make

appeal to principles that are different from those appropriate in describing ordinary kinds of living

beings.

Nonetheless, as we have seen, the spontaneous generation of living beings is a phenomenon

that occurs ‘either always or for the most part’ in crucial respects: it is a common, regular, frequent,

orderly and recurrent phenomenon, and as such, it is as much a part of the observed natural order as

the cyclical reproduction of living beings from parents of the same kind; therefore, as Aristotle

himself recognizes, it is a phenomenon that occurs κατὰ φύσιν – in accordance with the laws of

nature. As previously discussed, Aristotle maintains that some insects that grow spontaneously

come to be “according to nature in the spring (κατὰ φύσιν μὲν ἐν τῷ ἔαρι), but often in winter too

when (ὅταν) there has been a stretch of fair weather and southerly winds”.181

From a purely

empirical and descriptive point of view, this is no different from the way in which Aristotle

describes the periods of generation of ordinary species of insects, which copulate and breed

according to nature in the spring “but in the winter too, when (ὅταν) the weather is fine and south

winds prevail”.182

However, the fact that both forms of generation occur in definite seasons κατὰ φύσιν does

not imply that their manifest regularity, order, and frequency can be grounded on Aristotle’s

‘robust’ idea of φύσις, as Lloyd suggests. Consider, for example, the way in which in the Historia

Animalium Aristotle attempts to provide an explanation for the regular seasonal patterns of

generation of creatures that come to be through copulation:

For each kind of animal, there are definite seasons and ages for copulation. Indeed, the nature of

most of them (ἡ φύσις τῶν πλείστων) tends to dispose this intercourse at about the same period of the

year, and that is when winter is changing into summer: this is the season of spring, in which almost

all things that fly or walk or swim take to pairing. But some animals copulate and breed also (καὶ) in

autumn and in winter, as is the case with certain aquatic animals and certain birds.183

181

Hist. An. V 19, 551a 2-4. 182

Hist. An. V 9, 542b 27-29. 183

Hist. An. V 8, 542a 18-24.

56

It may be significant that Aristotle chooses to describe the order and regularity of the generation of

spontaneous creatures as happening κατὰ φύσιν, and yet not to attribute it to their φύσις, as he does

for creatures that reproduce their own kind. The use of these two different locutions seems to

suggest that the causal structure underlying the order and regularity manifested in these two cases is

dissimilar. In fact, a few lines after his remarks on the seasons of intercourse, Aristotle draws

attention to the fact that “many animals time their intercourse in the suitable season (ἐν τῇ

ἀπαρτιζούσῃ ὥρᾳ) with a view to the nurture of their young (πρὸς τὰς ἐκτροφὰς τῶν τέκνων)”.184

The teleological consideration here adduced appears to indicate that the order of the generations of

creatures that come to be from parents of the same kind can be grounded on an inherent and

autonomous principle, of which there is no equivalent in the case of creatures spontaneously

generated.

The distinction between reproduction from seed and spontaneous generation is clearly and

more conspicuously manifested in De Generatione Animalium. In the theoretical framework of this

book, in fact, the regularities attested in the cycles of generation of creatures that mate and

reproduce their own kind are clearly justified on the basis of their own inherent φύσις, where

‘φύσις’ is intended in the causally and ontologically robust sense of the term. In this context, to say

that the φύσις of most living beings disposes their intercourse in the suitable ὥρα ‘with a view to

the nurture of their young’ is to explain the regularity of their generation according to what is better

“in relation to the substance of each thing (πρὸς τὴν ἑκάστου οὐσίαν)”.185

In such cases, then, the

orderly seasonal patterns of generation of creatures that come to be through copulation is explained

by reference to an internal and teleologically determined principle, namely, the specific φύσις of

those creatures.

In the case of spontaneously generated creatures, by contrast, the suitable ὥρα of their

generation is not teleologically grounded on the φύσις of their own being, but is directly dependent

184

Hist. An. V 8, 541a 30-32. 185

Phys. B 7, 198b 9.

57

on the uniform causal conjunction of external events. As we have seen, both in the Historia

Animalium and De Generatione Animalium, Aristotle grounds the causal account of spontaneous

generation on the action of the sun and other heavenly bodies on different sorts of materials.186

In

such cases, the orderly and regular seasonal patterns of generation of spontaneous creatures are not

explained by an internal and teleologically determined principle, that is, by their φύσις; rather, their

order is explained by their causal correlation with the orderly motion of the heavenly bodies (ἡ τῆς

ὥρας κίνησις καὶ θερμότης),187

and their regularity by the differences of materials out of which they

come into being (κατὰ τὴν διαφορὰν τῆς ἰλύος ἕτερα).188

These above considerations suggest that although spontaneously generated creatures come

to be according to nature (κατὰ φύσιν), they do not come to be by nature (φύσει). Hence, although

Aristotle often uses the expressions ‘κατὰ φύσιν’ and ‘φύσει’ interchangeably, there are

nevertheless cases, especially in the biological works, in which these two expressions have different

senses.189

A general survey of the use of these two expressions by Aristotle reveals that everything that

happens φύσει can also be said to happen κατὰ φύσιν. In the Physics, for instance, Aristotle claims

that the property of fire to be carried upwards “is by nature and according to nature (φύσει καὶ κατὰ

φύσιν ἐστίν)”.190

In these contexts, the expressions ‘κατὰ φύσιν’ and ‘φύσει’ are equivalent and

used interchangeably because what Aristotle wants to say, more precisely, is that fire is carried

upwards ‘κατὰ τὴν αὑτοῦ φύσιν’191

– according to its own nature – or ‘κατὰ τὴν οἰκείαν φύσιν’192

–

186

Cfr. Part I, Chapter 6. 187

Cfr. De Gen. An. II 6, 743a 35-36. 188

Cfr. Hist. An. V 15, 547b 18-19. 189

This distinction helps to make sense of the intuition behind the difference between a ‘stronger’ and ‘weaker’ sense of

‘natural’ in STAVRIANEAS [2009], p. 303: “Both spontaneous, i.e. non-reproductive, and standard, i.e. reproductive,

generation processes are natural for Aristotle in that neither of them is contrary to nature and they both conform to some

regular pattern. However, in a stronger use of ‘natural’, only reproductive processes are natural because their end-

product is always, and from the start, their final cause.” 190

Phys. B 1, 192b 36 – 193a 1. 191

Cfr. for example Phys. A 9, 192a 18. 192

Cfr. for example Phys. E 10, 241b 1.

58

according to its appropriate nature – that is, according to a principle of change “in that to which it

belongs primarily of itself (ἐν ᾧ ὑπάρχει πρώτως καθ’ αὑτό)”.193

However, not everything that happens κατὰ φύσιν is said to happen φύσει. In its broadest

sense, the expression ‘κατὰ φύσιν’ only refers to what occurs ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ in the sense

of happening regularly, orderly, and frequently.194

Yet, many regular, frequent, and orderly

correlations recognized by Aristotle are not guaranteed a priori by the inner stability of φύσις itself

– that is, by the inner stability of the causal structures of the οὐσίαι populating the natural world –

but instead are justified a posteriori by empirical observations, as is the case with spontaneous

generation. This is not at all uncommon in Aristotle. Many phenomena concerning living creatures

occur ‘κατὰ φύσιν’ or ‘ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ’ without being causally dependent on the proper

nature of a substance. Consider, for instance, what Aristotle says about the regular periods of

menstruation:

Also the fact that menstruation occurs κατὰ φύσιν when the month is waning is due to the same

cause (διὰ τὴν αὐτὴν αἰτίαν). For this time of the month is colder and moister because of the waning

and failure of the moon; as the sun makes winter and summer in the year as a whole, so does the

moon in the month. This is not due to the turning of the moon, but it grows warmer as the light

increases and colder as it wanes.195

In this passage, Aristotle ties the period of the menstrual cycle with that of the lunar month,

insisting not so much on the equal duration of these two periods, but rather on the coincidence

between the beginnings of their phases. According to Aristotle, the cause of such a coincidence lies

in the influence of external thermal conditions, not in the inner nature of the creatures in question.

Menstruation occurs when the month is waning not because it is better for the substance of each

thing, but because it is colder as a result of the decrease in moonlight. This, then, offers not only

another example of a biological process in which order and frequency are grounded in the causal

193

Phys. B 1, 192b 22. 194

Cfr. De Part. An. III 2, 663b 27-29: “ἐν τῷ παντὶ ἢ τῷ ὡς ἐπὶ τὸ πολὺ τὸ κατὰ φύσιν ἐστίν”; De Gen. An. I 19, 727b

29-30 : “τὰ δ’ ὡς ἐπὶ τὸ πολὺ γιγνόμενα μάλιστα κατὰ φύσιν ἐστίν”; De Gen. An. IV 8, 777a 20-21 : “τὸ κατὰ φύσιν

ἐστὶ τὸ ὡς ἐπὶ τὸ πολύ”. 195

De Gen. An. IV 2, 767a 1-8. Cfr. for this passage PECK [1963] and LANZA & VEGETTI [1971] Ad. Loc.

59

uniformity of an external conjunction of events (διὰ τὴν αὐτὴν αἰτίαν), but also of a phenomenon

that occurs κατὰ φύσιν, yet not φύσει. In fact, Aristotle describes numerous other correlations of

this sort. Menstruation is but one example of many, since the very same causes mentioned at the

beginning of the passage – the influence of different environmental factors such as the northern and

southern winds – are used by Aristotle to explain the different ratio of generations of males and

females during particular periods of the year.

It is therefore an error to think that, in Aristotle’s view, all regular, orderly, and frequent

correlations of events are ultimately grounded in the inner causal structure of natural substances.196

Consider, for instance, his views on the different periods of gestation of animals:

The periods of gestation of each animal are, for the most part, determined in proportion to the length

of their life. For it is reasonable (εὔλογον) that the development of the long-lived animals should take

a longer time. Yet this is not the cause of it (οὐ μὴν τοῦτό γ’ ἐστὶν αἴτιον), but the correspondence

holds for the most part (ἀλλ’ ὡς ἐπὶ τὸ πολὺ τοῦτο συμβέβηκεν).197

This is another instance of a correlation that occurs κατὰ φύσιν, yet not φύσει. According to

Aristotle, the development of long-lived animals does not take a longer time because they are long-

lived. The correlation between the length of life and the length of development, as Aristotle claims,

is not grounded on the φύσις of animals; it is only presented as reasonable (εὔλογον) on the basis of

purely empirical regularity. Spontaneously generated creatures are treated in the same way.

Although spontaneous generation occurs κατὰ φύσιν, in the sense that it occurs always or for the

most part in the same way, when Aristotle provides a causal account of its occurrence, he never

claims that its regularity occurs φύσει – by nature – but εὐλόγως – with good reason.198

Finally, the fact that spontaneously generated creatures do not come to be φύσει becomes

even clearer if we look at one of the most general and theoretically significant statements about the

196

Cfr. for example DEPEW [2010], p. 287: “in Aristotle’s ontology, all sequences of events are, in the end, causally

grounded in the regular, properly causal behavior of natural or rational substances.” 197

De Gen. An. IV 10, 777a 32 – 777b 1. 198

The expression is used three times in De Gen. An. I 1, 715b 7-10, and two times in De Gen. An. III 11, 762a 1-8 to

refer to spontaneously generated creatures.

60

generation of ordinary living beings in De Generatione Animalium, in which Aristotle claims that

“whatever comes to be by nature (ὅσα φύσει γίγνεται) […] comes to be by a thing existing actually

out of what is potentially of that sort”.199

According to this principle, since spontaneously generated

creatures do not come to be by a thing existing actually out of what is potentially of that sort, it

follows that spontaneously generated creatures do not come to be by nature. This does not imply

that spontaneous generation is a random, rare, infrequent, or unknowable phenomenon, nor that it is

contrary to nature (παρὰ φύσιν), or that it fails to be caused ‘always or for the most part in the same

way’. In fact, spontaneous generation is a regular, common, frequent, orderly, and causally uniform

phenomenon, and as such, is consistently described by Aristotle as occurring κατὰ φύσιν. To deny

that spontaneous generation occurs φύσει only means that its regularity, frequency, order and causal

uniformity are not grounded on the inner φύσις of spontaneously generated creatures.

199

De Gen. An. II 1, 734b 21-22.

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10. Spontaneous Generation is Not Inconsistent with Aristotle’s Metaphysical Principles

If we take it as significant that Aristotle describes spontaneous generation as happening κατὰ φύσιν,

but not φύσει, then we are lead to reject Lloyd’s view that spontaneous generation is grounded in

Aristotle’ ‘robust’ idea of φύσις. However, the fact that spontaneous generation occurs κατὰ φύσιν,

but not φύσει, also leads us to reject the very opposite view, namely, that spontaneous generation

constitutes an exception to the norm set by Aristotle’s idea of φύσις. In point of fact, an exception to

the norm according to which ‘whatever comes to be by nature (ὅσα φύσει γίγνεται) comes to be by

a thing existing actually out of what is potentially of that sort’200

would be constituted by creatures

that come to be by nature (φύσει), yet not by a thing of that sort existing in actuality, for that would

imply that ‘not all things that come to be by nature come to be by a thing existing actually out of

what is potentially of that sort’. As it is, spontaneous generation does not challenge this norm since

it does not occur by nature.

Such reflections allow us to resolve one last puzzle concerning regular spontaneous

generation, namely, its alleged inconsistency with Aristotle’s own metaphysical principles. Hull is

arguably the greatest defender of the view that regular spontaneous generation is in conflict with

Aristotle’s metaphysics. According to Hull:

Central to Aristotle’s metaphysics is the view that in species of natural objects, as distinct from those

produced by art, the formal, final, and efficient causes are one. The end of any natural object is the

realization of its essence, and this same essence embodied in another individual is its efficient cause

(198a25). For example, the end of a particular horse is the realization of its essence, and this same

essence embodied in its male parent is its efficient cause.201

Hull points out that the occurrence of occasional monsters poses no real threat to this principle, as

“Aristotle says that the production of another like itself is only the most natural act”,202

which

200

Cfr. De Gen. An. II 1, 734b 21-22. 201

HULL [1967-1968], p. 246. 202

HULL [1967-1968], p. 246 (Hull’s italics).

62

allows for the possibility that “sometimes individuals might do very unnatural things”.203

Yet, the

occurrence of spontaneous generation, according to Hull, does pose a threat to Aristotle’s

metaphysics since “in the case of spontaneous generation this never happens. An individual never

successfully produces another like itself. The formal, final, and efficient causes never coincide”.204

Hull then concludes that Aristotle cannot plausibly maintain that “the only way individuals can

partake in the eternal and the divine is by like producing like,”205

since in spontaneous generation,

“there is regularity but like never produces like.”206

As we have seen, Hull maintains that “there are

always horses because horses tend to beget horses”,207

and argues that “this happens so regularly

because in these cases the efficient, formal, and final causes are one.”208

At the same time, however,

Hull claims that:

There are also always eels, although eels never give rise to other eels. Lower species of animals, both

as essences and as classes of organisms, are just as eternal as other species. The goal toward which

all things strive is to partake in the eternal and the divine. If lower animals can partake in the eternal

and divine without the help of efficient, formal, and final causes coinciding, why not all species?209

Hull also points out that Aristotle repeatedly criticizes his materialist predecessors in their attempt

to “explain the regularities present in nature just in terms of material and efficient causes.”210

And

yet, according to Hull, by allowing the regular spontaneous generation of living beings, “Aristotle

has capitulated to the materialists”.211

According to Hull, then, spontaneous generation challenges Aristotle’s metaphysics as a

recalcitrant datum, which his theory cannot account for, and poses the following dilemma: to save

the consistency of his position, Aristotle must either deny the existence of the datum, or modify

some of the basic tenets of his metaphysics. Thus, if Aristotle defends his metaphysical doctrine of

203

HULL [1967-1968], p. 246 (italics are mine). 204

HULL [1967-1968], p. 246 (Hull’s italics). 205

HULL [1967-1968], p. 247. 206

HULL [1967-1968], p. 247. 207

HULL [1967], p. 317. 208

HULL [1967], p. 317. 209

HULL [1967-1968], p. 247 (Hull’s italics). 210

HULL [1967], p. 317. 211

HULL [1967], p. 318.

63

formal and final causes, then the regular spontaneous generation of living beings ought not to be

possible; if, on the other hand, he maintains his belief in the regular spontaneous generation of

living beings, then his metaphysical doctrine of formal and final causes loses its force, and

Aristotle’s philosophy surrenders to the objections of the materialists.

This, however, is a false dilemma. We are now in a position to observe that Hull’s

accusations of inconsistency rest on the very same equivocation incurred by Lloyd in his attempt to

argue for the opposite view, namely, that spontaneous generation confirms and reinforces the most

fundamental metaphysical tenets of Aristotle’s philosophy. In both cases, in fact, the mistake

consists in conflating regularity with eternity. It is true, as Hull maintains, that ‘the only way

individuals can partake in the eternal and the divine is by like producing like;’ yet, once we

distinguish the eternity of ordinary species of living beings from the regularity of spontaneously

generated creatures, then the fact that in spontaneous generation ‘there is regularity but like never

produces like’ does not count as an exception to such a metaphysical principle. And again,

although it is true that ‘there are always horses because horses tend to beget horses’, it is not the

case that ‘this happens so regularly because in these cases the efficient, formal, and final causes are

one,’ as Hull claims. As we have seen, in fact, when Aristotle says that ‘there are always horses’, he

means to say that ‘there is a continuous generation of creatures that are one in form’, and this

happens because the efficient, formal, and final causes are one. But since in spontaneous generation

there is no continuous generation of creatures that are one in form, then it is not correct to say that

‘there are also always eels’. Indeed, the very fact that in the generation of eels the efficient, formal,

and final causes are not one explains why eels do not form eternal species.

The passage from Aristotle’s De Anima mentioned in Hull’s argument further proves the

fallacy of his reasoning. Hull is right in arguing that, on Aristotle’s view, the only way a living

being can partake in the eternal and the divine is by like producing like, that is, by the coincidence

of formal, final, and efficient causes. Yet, it is precisely because in spontaneous generation like

64

never produces like – in other words, because efficient causes do not coincide with formal and final

causes – that on Aristotle’s view spontaneously generated creatures do not participate in the eternal

and the divine. As it is, then, spontaneous generation is not inconsistent with one of Aristotle’s most

fundamental metaphysical principles, since a violation of such principle would be constituted by

animals in which like produces like without efficient, formal, and final causes coinciding, which is

precisely the materialist thesis repeatedly criticized by Aristotle, as evidenced in De Partibus

Animalium:

That is precisely why Empedocles misspoke when he said that many things are present in animals

because of how things happened during generation – for example, that the backbone is such as it is

because it happened to get broken through being twisted. He failed to understand, first, that seed (τὸ

σπέρμα) already constituted with this sort of potential must be present, and second, that its producer

was prior – not only in account but also in time. For one human being generates another (γεννᾷ γὰρ ὁ

ἄνθρωπος ἄνθρωπον); consequently, it is on account of that one being such as it is that this one’s

generation turns out a certain way.212

We are now also in a position to see that it is not the case that Aristotle criticizes his materialist

predecessors in their attempt to explain ‘the regularities present in nature just in terms of material

and efficient causes,’ contrary to what Hull claims. Once again, the passage from Aristotle’s

Physics mentioned in Hull’s argument further proves the error of his claim. As we have seen, Hull

maintains that in spontaneous generation, “the changes occur regularly whenever the appropriate

material is present and the conditions are right. They occur as regularly as ‘rain in winter’ and ‘heat

in the dog-days’”.213

Although, in this passage, Hull conflates the regularity of events with their

frequency, as we have previously noted, the reference to the causal uniformity behind both

spontaneous generation and meteorological phenomena such as rain and heat makes the refutation

of his claim all the more patent and significant. In fact, Aristotle does not criticize the materialist’s

explanation of meteorological phenomena; he agrees with the materialist that rain occurs in a

causally uniform way ‘whenever the appropriate material is present and the conditions are right’,

212

De Part. An. I 1, 640a 19-26 (translated by Lennox). 213

HULL [1967-1968], p. 247.

65

and that the causal uniformity of the relevant material and efficient causes is sufficient to explain

both its regularity and its frequency.214

But this means that Aristotle does not find fault in the

explanation of frequent and regular phenomena purely in terms of material and efficient causes.

What Aristotle does object to is his materialist opponent’s attempt to extend explanations that

appeal only to material and efficient causes, “to all things that are constituted by nature (ἐπὶ πάντων

τῶν φύσει συνισταμένων)”,215

and his failure to recognize formal and final causes “in the things that

are and come to be by nature (ἐν τοῖς φύσει γιγνομένοις καὶ οὖσιν)”.216

Finally, the distinction between ‘regular kinds’ and ‘eternal species’ allows us to solve one

last problem mentioned by Hull. He claims that one way to reconcile Aristotle’s belief in

spontaneous generation with his metaphysics is “to make the coincidence of formal, final, and

efficient causation defining species”.217

In this way, according to Hull, “if the members of a

‘species’ don’t reproduce themselves, that wasn’t a species”.218

However, Hull points out that such

a reconciliation is far from attractive and does not prevent other inconsistencies, because “if

spontaneously generated animals do not form species, then they are not the proper subject matter of

science, but Aristotle devotes considerable space to them, treating them on a par with other

animals”.219

Hull’s final quandary is resolved when we clarify that, on Aristotle’s view, the coincidence

of formal, final, and efficient causation is necessary for there to be eternal species. However,

eternal species do not exhaust the subject matter of science. Aristotle thinks that science is

concerned with what is or comes to be ‘always or for the most part’220

– namely with what is

regular, common, frequent, recurrent, orderly, and causally uniform – and in all of these respects, as

214

Although this view is supported by many scholars, it touches nonetheless a notoriously controversial issue in the

exegesis of Physics B 8; for a thorough discussion of this topic cfr. JOHNSON [2005]. 215

De Part. An. I 1, 640b 3-4; cfr. also. Phys. B 8, 198b 35. 216

Phys. B 8, 199a 7-8: “ἔστιν ἄρα τὸ ἕνεκά του ἐν τοῖς φύσει γιγνομένοις καὶ οὖσιν.” 217

HULL [1967-1968], p. 248. 218

HULL [1967-1968], p. 248. 219

HULL [1967-1968], p. 248-249. 220

Cfr. Metaph. E 2, 1027a 20-21; An. Pr. I 13 32b 18; and An. Post. I 30, 87b 20.

66

we have seen, spontaneously generated creatures are indeed on a par with creatures that reproduce

their own kind, and thus, are proper objects of scientific knowledge.

This solution holds even if we accept that only eternal species are ‘εἴδη’ in the proper and

ontologically significant sense of the term, namely that they are not just generic ‘groups’ or

‘classes’ of particular, concrete, unitary, and indivisible οὐσίαι sharing a common morphological

trait – what Aristotle describes as “the εἶδος upon the particulars (τὸ εἶδος ἐπὶ τῶν καθ’

ἕκαστον)”221

– but particular, concrete, unitary, and indivisible οὐσίαι in their own right.222

Indeed, this possibility seems to reflect Aristotle’s own convictions. The often repeated

claim ‘a man is generated by a man’ instantiates paradigmatically the very idea of a substantial

εἶδος – something that has in itself the principles of its own existence. But the incapacity of

spontaneously generated creatures to reproduce themselves, their discrete and episodic generations,

and their immediate dependence on other kinds of substances – the sun and the heavenly bodies –

appear to be in contrast with the sort of autonomy, concreteness, and unity characterizing

substantial species.223

The same conclusion is also suggested by Aristotle’s terminological choices,

as he avoids referring to spontaneously generated creatures as ‘species (εἴδη).’ Instead, as we have

seen, Aristotle tends to speak of spontaneously generated creatures as forming a group of creatures

sharing the same μορφή – the same shape – and even when he claims that spontaneously generated

creatures are ‘different τῷ εἴδει’ from other creatures, he uses the term ‘εἶδος’ in its original

221

Hist. An. II 15, 505b 31. This position is in line with the view endorsed in Cat. I 5, 3b 10-18: “Every substance

seems to signify a this (πᾶσα δὲ οὐσία δοκεῖ τόδε τι σημαίνειν). In the case of primary substances, it is indisputably true

that each of them signify a this; for what is revealed is an indivisible and is one in number (ἄτομον γὰρ καὶ ἓν ἀριθμῷ).

In the case of secondary substances, it appears from the character of the name, whenever one speaks of man or animal,

that they also signify a this. But this is not true; rather each signify a certain sort of thing (ἀλλὰ μᾶλλον ποιόν τι

σημαίνει), for the subject is not one (οὐ γὰρ ἕν τὸ ὑποκείμενον), as the primary substance is, but man and animal are

said of many things (ἀλλὰ κατὰ πολλῶν ὁ ἄνθρωπος λέγεται καὶ τὸ ζῷον)”. 222

Cfr. Metaph. Z 7, 1032b 1-2; Metaph. Z 8, 1034a 5-8; Metaph. Z 12, 1038a 19-20; Metaph. Z 17, 1041b 7-9; De

Part. An. I 2, 642b 5; De Part. An. I 3, 642b 35, 643a 7-8 and 19-20; and De Part. An. I 4, 644a 23-25 and 644a 29 –

644b 1 223

Cfr. KATAYAMA [1999], pp. 1-2, 10-11; 16-21; and 105-108.

67

etymological sense to refer to the visible somatic structure of such creatures, without suggesting

either a causal or an ontological role of such εἶδος.224

However, even if we accept that there is such an ontological difference between

spontaneously generated creatures and creatures that reproduce their own kind, such a difference

does not make spontaneously generated creatures any less proper objects of scientific knowledge.

Scientific knowledge is concerned with living beings insofar as they are and come to be ‘always or

for the most part in the same way,’ and since spontaneous generation is as regular, frequent,

common, orderly, recurrent, predictable, and causally uniform as the generation from parents of the

same kind, spontaneously generated creatures are as much in line with the laws of nature, and hence

as proper objects of scientific knowledge, as creatures born from parents of the same kind.

Thus, the ontological difference between spontaneous and ordinary creatures does not

preclude spontaneously generated creatures from being the subjects of a proper scientific – that is

causal – analysis. What the ontological difference between spontaneous and ordinary creatures does

preclude, however, is that they receive the same sort of scientific and causal analysis. In particular,

since spontaneously generated creatures do not form eternal species, since their generation is not

continuous, and since they do not possess the same sort of unity and autonomy characterizing

ordinary kinds of living creatures, the explanation of spontaneous generation need not appeal to the

sort of causes required to give a scientific explanation for those phenomena, that is, it does not need

to appeal to formal and final causes.

Spontaneously generated creatures constitute a ‘problem’ for Aristotle’s philosophy only on

the assumption that the value, strength, and goal of his philosophy reside in its capacity to bring

different and heterogeneous elements of reality back under a unitary set of general principles. Such

an assumption guides not only Hull’s critical evaluation of the way Aristotle handles spontaneous

generation, which condemns Aristotle’s philosophy as inconsistent for its incapacity to subsume

224

Cfr. Part I, Chapter 7.

68

spontaneous generation under the same causal principles that account for the generation of ordinary

creatures, but also Lloyd’s favorable assessment of it, which praises the strengths of Aristotle’s

philosophy for its capacity to bring spontaneous generation into line with his doctrine of the four

causes.

Such an assumption, however, is extraneous to Aristotle’s way of conceiving the nature of

philosophy. If we reject the idea that the strength or weakness of Aristotle’s philosophy is measured

by its capacity of subsuming the ‘many and diverse’ modes of generation present in nature under a

unitary set of principles, and recognize instead that for Aristotle, different kinds of objects require

different sorts of explanations, then we can rid ourselves of false alternatives – such as the question

of whether spontaneously generated creatures are included within the norm of φύσις or constitute an

exception to that norm – and gain more insight into Aristotle’s own way of thinking.

69

Part II

τὸ αὐτόματον in the Physics and the Metaphysics

70

1. Introduction

Arguably one of the most fertile and original fields of contemporary Aristotelian scholarship has

sprung up as a result of a renewed interest in the study of Aristotle’s biology. Most of the credit is

due to the pioneering and foundational work of David Balme, who explored Aristotle’s biological

texts with the conviction that we can find in them a fresh and precious source of material that

enables us to better understand and critically explore other areas of Aristotle’s philosophy, in

particular, his metaphysics, his philosophy of nature, and his logic. In fact, it would not be

overstated to say that as a result of Balme’s analyses, it has become indispensable for any work that

aims to provide an integrated account of some of the most central problems of Aristotle’s

philosophy to confront the details of his scientific practice as it has been developed in the biological

treatises.

Balme’s study of Aristotle’s biological account of spontaneity offers an example of the

methods employed and the results achieved by such a comparative analysis. Scholars who came

after Balme have experienced great difficulties in trying to reconcile Aristotle’s account of

spontaneous generation, as presented in the biological treatises, with the notion of τὸ αὐτόματον

that has been taken to emerge from treatises of a more theoretical nature, such as Physics B 4-6 and

Metaphysics Z 7-9. To fully understand this challenge, it might prove useful to review the two

constitutive elements of Aristotle’s definition of τὸ αὐτόματον in the Physics, and then analyze

what they entail for his biological account of spontaneity.

Firstly, in the Physics Aristotle consistently claims that τὸ αὐτόματον is a cause of things

that come to be “neither by necessity and always, nor for the most part (οὔτε τοῦ ἐξ ἀνάγκης καὶ

αἰεὶ οὔτε τοῦ ὡς ἐπὶ τὸ πολύ)”.1 This first aspect of τὸ αὐτόματον, as it has been clearly shown by

1 Phys. B 5, 196b 12-13, 20, and 196b 36 – 197a 1; 197a 20, and 34-5; B 8, 198b 36; 199b 24-24; cfr. also De Gen. et

Corr. II 6, 333b 6-7; De Caelo A 12, 283a 32 – 283b 1; Eth. Eud. VII 14, 1247a 31-33; Rhet. I 10, 1396a 32-34.

71

many scholars,2 stems from the fact that it is an accidental cause (αἴτιον κατὰ συμβεβηκός),

3 and

accidental causes are not responsible for things that come to be “either always or for the most part

in the same way (ἢ ἀεὶ ἢ ὡς ἐπὶ τὸ πολύ ὡσαύτως)”.4 This implies that its occurrences are random

(ὅπως ἂν τύχῃ),5 indeterminate (ἀόριστον),

6 obscure to the human mind (ἄδηλος ἀνθρωπίνῃ

διανοίᾳ)7 and not susceptible of scientific understanding (ἐπιστήμη οὐκ ἔστιν αὐτοῦ).

8

Secondly, Aristotle claims that τὸ αὐτόματον brings about the same sort of results that are

normally produced by a teleological process, being responsible for things “such as might come to

be for the sake of something (ὅσ’ ἂν γένοιτο ἕνεκά του)”.9 Aristotle explains that the things that

‘might come to be for the sake of something’ are the sort of things “which might have come to be as

the result of thought or nature (ὅσα τε ἀπὸ διανοίας ἂν πραχθείη καὶ ὅσα ἀπὸ φύσεως).”10

Together,

these two elements allow Aristotle to define τὸ αὐτόματον as the accidental cause “of things for

which mind or nature could be responsible (ὧν ἂν ἢ νοῦς γένοιτο αἴτιος ἢ φύσις)”.11

According to

this definition, then, whenever something which is normally or usually brought about by a

teleological process – that is, by nature or by a deliberate action – comes to be as the result of an

accidental cause, we say that it comes to be ἀπὸ τοῦ αὐτομάτου.

2 Cfr. LENNOX [1982], pp. 230-232; JUDSON [1991], pp. 76-79.

3 Phys. B 5, 196b 23; 197a 5-6, 12-14, and 33; B 6, 198a 6-7; Metaph. E 2, 1026b 31-33; 1027a 7-8 and 26; Metaph.

30, 1025a 14-15; Metaph. K 8, 1065a 1-3, 28, 30, and 34. 4 Cfr. Phys. B 5, 196b 10-11: “Πρῶτον μὲν οὖν, ἐπειδὴ ὁρῶμεν τὰ μὲν ἀεὶ ὡσαύτως γιγνόμενα τὰ δὲ ὡς ἐπὶ τὸ πολύ,

φανερὸν ὅτι οὐδετέρου τούτων αἰτία ἡ τύχη λέγεται οὐδὲ τὸ ἀπὸ τύχης, οὔτε τοῦ ἐξ ἀνάγκης καὶ αἰεὶ οὔτε τοῦ ὡς ἐπὶ τὸ

πολύ”. To be precise, in this passage Aristotle is referring to what is said (λέγεται) about τύχη, not τὸ αὐτόματον (cfr.

Part II, Chapter 7). Similarly, cfr. Eth. Eud. VII 14, 1247a 31-33, the only other occasion in which Aristotle makes use

of this expression: “ἀλλὰ μὴν ἥ γε φύσις αἰτία ἢ τοῦ ἀεὶ ὡσαύτως ἢ τοῦ ὡς ἐπὶ τὸ πολύ, ἡ δὲ τύχη τοὐναντίον.” 5 Phys. B 4, 196a 22; B 5, 197a 22; Metaph. E 2, 1027a 17; Metaph. 30, 1025a 25; Metaph. K 8, 1064b 36; cfr. also

De Caelo B 5, 287b 24-25 and B 8, 289b 25-27. 6 Phys. B 5, 196b 28; 197a 8, 9, and 20-21; B 6, 198a 5; Metaph. 30, 1025a 25; Metaph. K 8, 1065a 25, 32-33; cfr.

also An. Pr. I 13, 32b 10; Rhet. I 10, 1396a 32-34. 7 Phys. B 4, 196b 6; cfr. also Phys. B 5, 197a 10.

8 Metaph. E 2, 1026b 26-27; cfr. also Metaph. E 2, 1026b 3-5; 1027a 19-21; Metaph. K 8, 1064b 17-19, 30-32, 1065a

3-6, 33-34; Phys. B 5, 197a 18; An. Post. I 30, 87b 19-21. 9 Phys. B 5, 197a 35; cfr. also 196b 21: “to which it belongs to be for the sake of something (περὶ ἃ ἐνδέχεται ὑπάρχειν

τὸ ἕνεκά του).” 10

Phys. B 5, 196b 22; cfr. also Metaph. K 8, 1065a 26-32: “ὸ δὲ ἕνεκά του ἐν τοῖς φύσει γιγνομένοις ἢ ἀπὸ διανοίας

ἐστίν, τύχη δέ ἐστιν ὅταν τι τούτων γένηται κατὰ συμβεβηκός· ὥσπερ γὰρ καὶ ὄν ἐστι τὸ μὲν καθ’ αὑτὸ τὸ δὲ κατὰ

συμβεβηκός, οὕτω καὶ αἴτιον. ἡ τύχη δ’ αἰτία κατὰ συμβεβηκὸς ἐν τοῖς κατὰ προαίρεσιν τῶν ἕνεκά του γιγνομένοις, διὸ

περὶ ταὐτὰ τύχη καὶ διάνοια.” 11

Phys. B 6, 198a 6.

72

A number of scholars have pointed out that the application of the Physics’ account of τὸ

αὐτόματον to the generation ἀπὸ τοῦ αὐτομάτου of living beings entails a theory of random

spontaneous generation, that is, the belief in the unusual generation without seed of creatures

belonging to species whose members for the most part are generated from seed. This seems to

conflict with the regular spontaneous generation endorsed in the biological works, that is, the belief

in the regular generation without seed of creatures belonging to species whose members are always

generated from seed. In fact, according to the definition provided in the Physics, a thing is said to

come to be ἀπὸ τοῦ αὐτομάτου only if for the most part it is brought about by a deliberate action or

by nature. Hence, when applied to nature, and in particular to the generation of living beings, the

Physics’ account appears to entail that living creatures generated ἀπὸ τοῦ αὐτομάτου should belong

to species whose members are for the most part generated from parents of the same kind. As

Lennox has put it in his analysis of τὸ αὐτόματον in the Physics:

Aristotle insists that an outcome can be labelled spontaneous only if it normally is produced

teleologically. Thus, if some sea urchins are produced spontaneously, we should expect a much

larger number to be reproduced.12

Balme is the first scholar to have clearly criticized Aristotle on the ground of inconsistency between

the account of τὸ αὐτόματον in the Physics and the description of generation ἀπὸ τοῦ αὐτομάτου

offered in the biological works. Indeed, according to Balme, whereas in the Physics Aristotle

maintains that “in any given product spontaneity appears as an unusual exception,”13

in his zoology,

by contrast, he draws a clear distinction “between those animals which are always spontaneously

generated and the remainder, which never are […], and the sense of παρὰ τὸ ὡς ἐπὶ τὸ πολύ is

attached not to it but to τέρατα”.14

Hence, according to Balme, the account of τὸ αὐτόματον

provided in the Physics is ‘inapplicable’ to the treatment of spontaneity in the Historia Animalium

12

LENNOX [1982], p. 238. 13

BALME [1962], p. 97 (italics are mine). 14

BALME [1962], p. 97 (italics are mine); cfr. also p. 100.

73

and De Generatione Animalium, since in these treatises the creatures that are said to be generated

ἀπὸ τοῦ αὐτομάτου belong to species whose members are always, without exception, spontaneously

generated.15

Although Balme recognizes that Physics B 4-6 does not directly address the phenomenon of

spontaneous generation, he nonetheless argues that the view entailed by the account of τὸ

αὐτόματον in the Physics is in fact endorsed by Aristotle in Metaphysics Z 7-9.16

The pivotal

evidence upon which Balme relies comes from a passage of Metaphysics Z 7, in which Aristotle

claims that in nature “sometimes the same things come to be both from seed and without seed (ἔνια

ταὐτὰ καὶ ἐκ σπέρματος γίγνεται καὶ ἄνευ σπέρματος)”.17

Balme interprets this passage as saying that individual organisms belonging to the same

species whose members for the most part are generated ἐκ σπέρματος can sometimes be generated

also ἄνευ σπέρματος, and he believes that both in the Physics and in the Metaphysics Aristotle

“accepts the spontaneous generation of the same animals as are also sexually generated.”18

However, as he insists that there is “no evidence of such animals in Aristotle’s biological works”,19

and that such a view is “completely at variance with the treatment of spontaneity in Aristotle’s

actual zoology,”20

Balme concludes that we should recognize in Aristotle the presence of two

conflicting accounts of spontaneous generation.

According to Balme, this conflict attests the presence of a doctrinal development in

Aristotle’s thought. On Balme's view, the Physics and the Metaphysics, which endorse a theory of

random spontaneous generation, present an earlier and more speculative account of spontaneity.

15

BALME [1962], p. 98. 16

BALME [1962], p. 96: “Spontaneity brings about the same ends as are normally caused by purposeful act or by

nature. In Phys. and An. Post. this is stated only of the products of διάνοια, such as health or safety, 197a 23, 95 a 3-5.

But in Met. it is stated of nature too.” 17

Cfr. BALME [1962], p. 96. The passage referred to is Metaph. Z 7, 1032a 30-32. 18

BALME [1962], p. 104. 19

Cfr. BALME [1962], p. 97. 20

BALME [1962], p. 97; cfr. also pp. 99-100: “The […] question remains: is there any support for Met. Z 1032a 31

ἔνια ταὐτὰ καὶ ἐκ σπέρματος γίγνεται καὶ ἄνευ σπέρματος? ROSS [1924], p. 183 Ad Loc. cites the cases of eels (H.A.

570a 7), fishes (569a 11), testaceans (547b 18, G.A. 761b 23), insects (539a 24, G.A. 732b 12). But, as has been seen,

in none of these cases does De Generatione Animalium give the generation of any one species both ἐκ σπέρματος and

ἀπ’αὐτομάτου, and in this matter the Historia Animalium presents the same view.”

74

Such a belief, according to Balme, finds its origin in a purely theoretical approach to the study of

nature, one that is not dependent on empirical research, but is mainly grounded on “popular

medicine and agriculture,” on the one hand, and abstract “logical or ontological analysis,” on the

other.21

By contrast, the Historia Animalium and De Generatione Animalium, which endorse the

notion of regular spontaneous generation, present a later and more empirically informed account of

spontaneity. This belief, according to Balme, finds its origin in a more genuinely scientific approach

to the study of nature, one which relies on factual observations, and which compelled Aristotle to

abandon his original theory.

Although not all scholars have accepted Balme’s developmental claims, most contemporary

studies on spontaneous generation are framed around Balme’s central thesis that there is an apparent

conflict between the theoretical account of spontaneous generation put forward in treatises of a

more metaphysical and speculative nature, such as the Physics and the Metaphysics, and the

biological account endorsed in more empirically informed works, such as the Historia Animalium

and De Generatione Animalium.22

Gotthelf, for instance, concurs with the view that the account of spontaneous generation of

Metaphysics Z 7-9 and Physics B 4-6 is different from that of the biological works, since according

to the account presented in the former treatises:

most of the members of species in which there are spontaneous generations should be generated

sexually, but that is precisely not so according to De Generatione Animalium III 11, which insists

that all or virtually all of the testacea, all of the eels, all of certain species of river fish, and all of

certain species of insects are generated spontaneously.23

Judson too agrees with Balme’s claim of inconsistency between the theoretical account of

spontaneity of the Physics and the Metaphysics and the biological account of the Historia

Animalium and De Generatione Animalium. Although Judson recognizes the presence of an

21

BALME [1962], p. 93. 22

Cfr. BOSTOCK [2006], p. 75: “The theory of spontaneous generation was one which he felt had to be accepted, in

the light of what he took to be the observed facts about some peculiar creatures such as shellfish”. 23

GOTTHELF [1989], p. 182.

75

equivocal use of the term ‘αὐτόματον’ in Aristotle, he does not believe that recognizing equivocal

uses can solve the apparent conflict between regular and random spontaneous generation.

In De Motu Animalium 7, Aristotle uses the term ‘αὐτόματον’ to describe the sort of

automatic devices that appear to move themselves by virtue of an internal mechanism, such as

Homer’s tripods invented by Hephaestus.24

According to Judson, although both the mechanical

αὐτόματα described in De Motu Animalium 7 and the phenomena described in Physics B 4-6 as

occurring ἀπὸ τοῦ αὐτομάτου “imitate the workings of some natural or deliberative subject,” their

resemblance does not extend further, for while mechanical αὐτόματα operate “in a regular,

repeatable, and predictable way”, things that come to be ἀπὸ τοῦ αὐτομάτου are, according to

Aristotle, “anomalous, irregular, and opaque to science”.25

Judson maintains that this difference ought not to be interpreted as exposing any real

inconsistency in Aristotle’s thought; rather, it merely shows that the term ‘αὐτόματον’ is inherently

equivocal – that Aristotle uses the same name for different phenomena – so that “the problem of

wholesale inconsistency does not arise”.26

However, Judson does not think that recognizing the

‘mechanical’ sense of τὸ αὐτόματον can resolve the apparent inconsistency between the random

spontaneous generation of the Physics and the Metaphysics, and the regular spontaneous generation

of the biological treatises:

Note, however, that generation ἀπὸ τοῦ αὐτομάτου (καὶ ἀπὸ τύχης) in Metaphysics Z seems to be

chance generation – exceptional cases in which an animal normally generated from seed is generated

without seed – and not the regular spontaneous generation discussed in the biological works.27

According to Judson, therefore, the different versions of generation ἀπὸ τοῦ αὐτομάτου of living

beings cannot be explained by appealing to a solution that relies on equivocation, unlike the use of

the term ‘τὸ αὐτόματον’ to describe both automatic mechanical devices and phenomena due to

24

Cfr. De Motu An. 7, 701b 1-10. 25

JUDSON [1991], p. 74. 26

JUDSON [1991], p. 74. 27

JUDSON [1991], p. 74.

76

chance. In other words, Judson does not believe that Aristotle uses the same name for different

phenomena. Instead, he believes that Aristotle displays different beliefs – indeed inconsistent beliefs

– about the same phenomenon, namely the generation of living beings ἄνευ σπέρματος. In

particular, Judson believes that the account of spontaneous generation endorsed in Metaphysics Z 7-

9 conforms to the definition of τὸ αὐτόματον and τύχη in Physics B 4-6 and is therefore a form of

chance generation, while the account endorsed in the biological works is a form of regular

generation, which fails to conform to the criteria of Physics B 4-6.

Bostock, for his part, confronts the same problem in his commentary on Metaphysics Z 7-9,

wherein he claims that:

[Aristotle] appears to imply that all living things spontaneously generated can also be generated from

seed, whereas De Generatione Animalium denies this. This clash could be partly avoided by

supposing that he is speaking of different phenomena in the two places, i.e. in De Generatione

Animalium of the regular generation of certain species of animals without seed, and here of the

irregular and unusual generation, without seed, of animals that are standardly generated from seed.28

Bostock’s proposal is indeed, if anything, only a partial solution to the conflict that he sees between

the Metaphysics and the biological treatises. Unlike Judson, Bostock is willing to accept the idea of

an equivocal use of τὸ αὐτόματον for different forms of generation ἄνευ σπέρματος; however, even

if we were to accept that Aristotle actually did believe that there are two distinct biological

phenomena that fall under the heading ‘generation ἀπὸ τοῦ αὐτομάτου’, what Bostock fails to

explain is why the phenomenon of regular spontaneous generation of the biological treatises is

never discussed in Aristotle’s theoretical treatises, and why the phenomenon of random

spontaneous generation is not only absent from, but also, as we shall see, outright denied by

Aristotle in his biological treatises.

More recently, Balme’s developmental solution has been defended by Dudley in his

monograph on Aristotle’s concept of chance. Dudley, too, agrees with the view that in Metaphysics

28

BOSTOCK [1994], pp. 138-139.

77

Z, “Aristotle held that some animals are generated both by means of semen and by spontaneous

generation, a theory that is sometimes referred to as that of random spontaneous generation”.29

He

claims that such a theory “fits in much better with the classification of spontaneous generation

under ταὐτόματον in the Physics”,30

and hence, he concludes that “Aristotle may well have believed

in random spontaneous generation at the time of writing the Physics”.31

Given the ‘clash’ between

the doctrine in Metaphysics Z and the views accepted in the biological works, Dudley endorses

Bostock’s suggestion that Aristotle is talking about two different phenomena in these texts, namely,

of the ‘irregular and unusual’ generation without seed of animals that are normally generated from

seed, in the first instance, and of the regular generation of certain species of animals without seed,

in the second. Yet, he also points out that such a suggestion “is likely only on the supposition that

Aristotle had originally believed in random spontaneous generation and abandoned it by the time of

writing De Generatione Animalium”.32

Despite the different attempts that have been made to explain the apparent conflict in

Aristotle’s works, the basic outline of the problem identified by Balme has become so entrenched in

Aristotelian scholarship as to frame what can be referred to as the standard interpretation of the

theory of spontaneity taken to emerge from the Physics and the Metaphysics.

According to this interpretation, in Physics B 4-6, Aristotle draws a distinction between a

generic and a specific sense of ‘τὸ αὐτόματον’. As a genus, ‘τὸ αὐτόματον’ stands for the general

phenomenon of chance, which Aristotle divides into two species, namely ‘τύχη’, which stands for

the phenomenon of luck and is the specification of chance within the human practical domain, and

‘τὸ αὐτόματον’ in the alleged specific sense, which stands for the phenomenon of spontaneity and is

the counterpart of τύχη in the natural world. Commentators who follow this line of thinking also

believe that in Physics B 4-6, Aristotle focuses mainly on the general definition of chance and the

29

DUDLEY [2012], p. 185, 187, and 190. 30

DUDLEY [2012], p. 185 and 190. 31

DUDLEY [2012], p. 193. 32

DUDLEY [2012], p. 187.

78

analysis of the specific phenomenon of luck, while leaving the analysis of the specific phenomenon

of spontaneity to Metaphysics Z 7-9. Together, Physics B 4-6 and Metaphysics Z 7-9 are believed to

present Aristotle’s ‘theoretical’ account of spontaneity, which endorses what is commonly referred

to as ‘random’ spontaneous generation, namely the unusual generation without seed of individual

organisms belonging to species whose members are for the most part generated from seed. On this

interpretation, the more speculative ‘theoretical’ account of spontaneity is believed to be in

opposition to the more empirically informed ‘biological’ account of spontaneity, that is to say, the

account defended in Historia Animalium and De Generatione Animalium, which endorses what is

referred to as ‘regular’ spontaneous generation, namely the regular generation without seed of

individual organisms belonging to species whose members are always generated without seed.

As none of the solutions proposed to resolve the apparent conflict in Aristotle’s texts is

satisfactory, and as the debate over spontaneous generation appears to have reached an impasse, it is

necessary to examine, and challenge, the very legitimacy of the standard framework on which the

identification of the problem is grounded, and the assumptions on which it rests. The basic

framework in question, which has informed all the literature on the topic that has come after it,

finds its roots in the distinction between Aristotle’s ‘theoretical’ and ‘biological’ account of

spontaneity, a distinction that conceals rather than clarifies Aristotle’s thought. An underlying and

unchallenged assumption of this interpretation is that the account of τὸ αὐτόματον presented in the

Metaphysics corresponds with and builds upon the account of τὸ αὐτόματον presented in the

Physics – hence the idea that these two works present a unitary and univocal theoretical account of

spontaneity.

Instead of relying on this problematic framework, perhaps a better approach to interpreting

Aristotle’s accounts of τὸ αὐτόματον would be to begin by gaining a careful awareness of the

different problems that Aristotle discusses in these works and the different contexts in which these

discussions take place. Hence, to test the legitimacy of the standard interpretation and offer an

79

alternative and more profitable solution to the apparent conflict, we ought to begin by approaching

the Metaphysics’ and the Physics’ accounts of τὸ αὐτόματον separately, examining each on its own

terms and with a view to highlighting their differences and peculiarities. What this analysis will

show is that the idea that the Physics implies, and Metaphysics endorses, the belief in what is now

referred to as ‘random’ spontaneous generation, is based more on the assumption of a common

account of τὸ αὐτόματον in the Physics and the Metaphysics rather than on actual textual evidence;

in fact, textual evidence reveals that the account of spontaneity in the Metaphysics is actually

consistent with and dependent upon the account in the Historia Animalium and De Generatione

Animalium, not the account in the Physics.

Once the close connection between the account of spontaneity in the Metaphysics and its

foundation in the biological works is made clear, then it is possible to recognize that the treatment

of τὸ αὐτόματον in the Physics bears only superficial similarities to that of the Metaphysics, and

that the assumption that these two treatises present a univocal ‘theoretical’ account of spontaneity is

untenable. By distinguishing the account of the Physics – with its practical model, generalizing

argument, and polemical approach, which targets hypotheses developed in the context of natural

philosophy – from that of the Metaphysics – with its productive model, analogizing argument, and

constructive approach, which rests on hypotheses developed in the context of medical science – we

can reject the old distinction between the alleged ‘generic’ and ‘specific’ sense of ‘τὸ αὐτόματον’,

and show that the two works are in fact concerned with two distinct types of phenomena. This

proposal, as we shall see, shows that there is no inconsistency in Aristotle’s account of

τὸ αὐτόματον as it reveals that the Physics and the Metaphysics are devoted to the analysis of

different and equivocal phenomena. While the Metaphysics, with its constructive approach,

provides Aristotle’s own account of the spontaneous generation of individual organisms – an

account which he endorses in his biological works – the Physics, with its polemical examination of

80

Presocratic cosmogonies and zoogonies, provides an account of the chance generation of

entire species of organism, which Aristotle rejects in his biological works.

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2. Random Spontaneous Generation in Metaphysics Z 7-9: The Standard Interpretation

In order to test the legitimacy of the standard interpretation of the apparent conflict between

Aristotle’s alleged ‘theoretical’ account of spontaneity and its ‘biological’ counterpart, we should

begin by examining its reading of the Metaphysics’ references to spontaneous generation, as

displaying Aristotle’s commitment to the existence of random spontaneous generation.

At the very heart of the Metaphysics, namely Chapters 7 to 9 of Book Z, Aristotle begins his

general inquiry on coming into being with a threefold division. He claims that “among the things

that come into being (τῶν γιγνομένων), some come into being by nature (φύσει), some by art

(τέχνῃ), and some from spontaneity (ἀπὸ ταὐτομάτου)”.33

In the first part of his inquiry, Aristotle

focuses on the things that come to be by nature (φύσει), such as “a man or a plant or one of the

things of this kind (ἄνθρωπος ἢ φυτὸν ἢ ἄλλο τι τῶν τοιούτων) which we say are substances most

of all (ἃ δὴ μάλιστα λέγομεν οὐσίας εἶναι)”.34

What characterizes each of these things, in Aristotle’s

view, is the fact that “that by which (τὸ δὲ ὑφ’ οὗ)”35

they come into being is itself “something

which exists by nature (τῶν φύσει τι ὄντων)”.36

To clarify his statement, Aristotle tells us that what

ontologically characterizes all natural generations is that the nature (ἡ φύσις) of that by which (ὑφ’

οὗ) they come into being – “nature meant according to the form (ἡ κατὰ τὸ εἶδος λεγομένη

φύσις)”37

– is “the same in form (ὁμοειδής)”38

as the nature of that which comes into being, “for

man generates man (ἄνθρωπος γὰρ ἄνθρωπον γεννᾷ)”.39

It is important to note that Aristotle makes his celebrated remark that ‘man generates man’

not only to provide an example of something which comes into being by nature, but also, and more

generally, to instantiate a paradigmatic case of something which comes into being “from something

33

Metaph. Z 7, 1032a 12-13. 34

Metaph. Z 7, 1032a 18-19. 35

Metaph. Z 7, 1032a 17-18. 36

Metaph. Z 7, 1032a 18. 37

Metaph. Z 7, 1032a 24. 38

Metaph. Z 7, 1032a 24. 39

Cfr. Metaph. Z 7, 1032a 24-25.

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synonymous (ἐκ συνωνύμου)”.40

Indeed, after characterizing natural generations (αἱ γενέσεις αἱ

φυσικαὶ) – that is, the generation of things which come to be by nature (φύσει) – Aristotle proceeds

to discuss artificial productions (αἱ ποιήσεις) – that is, the generation of things which come to be by

art (τέχνῃ). He claims that “in a way (τρόπον τινά),”41

generation from synonym extends also to

such cases, since “health comes from health and house from house (τὴν ὑγίειαν ἐξ ὑγιείας γίγνεσθαι

καὶ τὴν οἰκίαν ἐξ οἰκίας), […] for the medical art and the building art are the form of health and of

the house (ἡ γὰρ ἰατρική ἐστι καὶ ἡ οἰκοδομικὴ τὸ εἶδος τῆς ὑγιείας καὶ τῆς οἰκίας)”.42

With this, Aristotle does not intend to obscure the difference between what comes to be by

nature and what comes to be by art – after all, he is explicit in pointing out that the medical art and

the building art are “the form in the soul (τὸ εἶδός ἐστι τὸ ἐν τῇ ψυχῇ).”43

Rather, by stating that ‘in

a way (τρόπον τινά)’ products of art too come to be from synonyms, Aristotle pushes this difference

into the background so as to emphasize a more fundamental division, namely, that between what

comes to be from synonymous causation, which includes whatever comes to be either by nature

(φύσει) or by art (τέχνῃ), and what comes to be in the absence of synonymous causation, which he

identifies with what comes to be from spontaneity (ἀπὸ ταὐτομάτου). In the Metaphysics, in fact,

spontaneity (τὸ αὐτόματον) is defined primarily as a privation (στέρησις) of synonymous causation,

so that generation ἀπὸ ταὐτομάτου ought to be understood primarily in terms of absence of

isomorphism between that which comes into being (τὸ τὶ γίγνεται) and that by which it comes into

being (τὸ ὑφ’ οὗ γίγνεται).

Aristotle illustrates the possibility of coming into being ἀπὸ ταὐτομάτου by focusing on

examples of what may come to be in the absence of τέχνη, that is, in the absence of artificial

40

Metaph. 3, 1070a 5. BRENTANO [1862], pp. 50-53 and 59-60 refers to it as the “Law of Synonymy”. In Cat. 1a 6-

7, Aristotle claims that “when things have the name in common (τό τε ὄνομα κοινὸν) and the definition of being which

corresponds to the name is the same (καὶ ὁ κατὰ τοὔνομα λόγος τῆς οὐσίας ὁ αὐτός), they are called synonymous

(συνώνυμα)”. Note, however, that in the parallel passage of Metaph. Z 9, 1034a 22, Aristotle uses the expression ‘ἐξ

ὁμωνύμου;’ as ROSS [1924], p. 192 and 355 has pointed out, the two expressions are here used with no distinction in

meaning, according to the ordinary Greek usage. For an account of the relations between Metaph. Z 7-9 and 3, cfr.

JUDSON [2000], pp. 113-124, and KATAYAMA [1999], pp. 14-23. 41

Metaph. Z 7, 1032b 11. 42

Metaph. Z 7, 1032b 11-14. 43

Metaph. Z 7, 1032b 23.

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synonymous causation. Things that come to be by virtue of an art – such as a house or health –

come to be by virtue of a productive cause that has the same form as that which is produced – such

as the art of building or the art of medicine. But if ever one of these products – a house, or health –

were to come to be in the absence of an isomorphic cause, namely, without the actions of a builder

or a doctor, then we would say that such a thing came about ἀπὸ ταὐτομάτου. It is important to

stress that Aristotle is not committed to the view that anything which comes to be ἀπὸ τέχνης can

also come to be ἀπὸ ταὐτομάτου, but only that some of them (τούτων τινες) can.44

In fact, in

Metaphysics Z 9, Aristotle clearly asserts that only “some things (τὰ μὲν), such as health, come to

be both by art and from spontaneity (καὶ τέχνῃ καὶ ἀπὸ ταὐτομάτου), whereas others do not (τὰ δ’

οὔ), as for example a house”.45

According to some scholars, it seems only natural to conclude that if that which is generated

in the absence of natural synonymous causation comes to be just as that which is produced in the

absence of artificial synonymous causation, then Metaphysics Z 7-9 provides evidence that

Aristotle endorsed a theory of random spontaneous generation. They maintain that Aristotle’s

remark that ‘a man comes to be from a man’ is used to show that things that come to be by nature,

come to be in virtue of generative causes that have the same nature or form as that which is

generated. It would seem to follow, then, according to this interpretation, that if ever a man were to

come to be in the absence of synonymous causation, namely, not from something having the same

form, we would have to say that such a man came about ἀπὸ ταὐτομάτου. Again, it is important to

stress that those who interpret the Metaphysics in this way do not maintain that Aristotle commits

himself to the belief that anything which comes to be φύσει can also come to be ἀπὸ ταὐτομάτου –

indeed, as we shall see, Aristotle considers the view that ‘men and other quadrupeds’ might be

44

Metaph. Z 7, 1032a 28-29. 45

Metaph. Z 7, 1034a 9-10. The same point is reiterated in An. Post. II 11, 95a 3-5: “among the products of thought (ἐν

δὲ τοῖς ἀπὸ διανοίας), some never occur spontaneously (τὰ μὲν οὐδέ ποτεἀπὸ τοῦ αὐτομάτου ὑπάρχει), such as a house

or a statue, nor from necessity either, but with some aim; but others occur by chance too (τὰ δὲ καὶ ἀπὸ τύχης), such as

health and safety (οἷον ὑγίεια καὶ σωτηρία)”.

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generated in this way to be a mere relic of mythical beliefs.46

These scholars maintain only that

Aristotle is committed to the belief that some of the things that come to be φύσει can also come to

be ἀπὸ ταὐτομάτου. The most important and controversial passage, which has been taken as

evidence in support of this reading, is found in Metaphysics Z 7:

οὕτω μὲν οὖν γίγνεται τὰ γιγνόμενα διὰ τὴν φύσιν, αἱ δ’ ἄλλαι γενέσεις λέγονται ποιήσεις. πᾶσαι δὲ

εἰσὶν αἱ ποιήσεις ἢ ἀπὸ τέχνης ἢ ἀπὸ δυνάμεως ἢ ἀπὸ διανοίας. τούτων δέ τινες γίγνονται καὶ ἀπὸ

ταὐτομάτου καὶ ἀπὸ τύχης παραπλησίως ὥσπερ ἐν τοῖς ἀπὸ φύσεως γιγνομένοις· ἔνια γὰρ κἀκεῖ

ταὐτὰ καὶ ἐκ σπέρματος γίγνεται καὶ ἄνευ σπέρματος.47

Ross translates this passage as follows:

Thus, then, are natural products produced; all other productions are called ‘makings’. And all

makings proceed either from art or from a capacity or from thought. Some of them happen also

spontaneously or by chance just as natural products sometimes do; for there also the same things

sometimes are produced without seed as well as from seed.48

Note that those who claim that this passage offers evidence that Aristotle believed in random

spontaneous generation are making two crucial assumptions. First, by insisting that what comes to

be spontaneously in the field of natural generations occurs just as what comes to be spontaneously

in the field of artificial productions, they assume that spontaneous generations and spontaneous

productions are two specific instantiations of the same general phenomenon. In other words, they

assume that what comes to be spontaneously in the field of nature has the same structure and

follows the same principles as what comes to be spontaneously in the field of productive activities.

Second, they assume that the presence of causation ἐκ συνωνύμου guarantees the regularity of both

natural generations and artificial productions, and conversely, that the στέρησις of synonymous

46

Cfr. Part II, Chapter 9. 47

Metaph. Z 7, 1032b 25-32. 48

Cfr. Reale’s translation: “In questo modo, dunque, ha luogo il processo di generazione delle cose che si generano

secondo natura; gli altri processi di generazione, invece, si chiamano produzioni. E tutte le produzioni hanno luogo o ad

opera di un’arte o ad opera di una facoltà o ad opera del pensiero. Alcune di queste, però, si producono anche

spontaneamente e ad opera del caso, come avviene talora anche nelle generazioni naturali: infatti anche in natura, certi

esseri si generano in egual modo sia dal seme sia senza seme.” Note that both ROSS [1924], p 183 and REALE [2004],

p. 1030 believe that in this passage Aristotle is referring to the theory of spontaneous generation presented in Historia

Animalium and De Generatione Animalium.

85

causation is responsible for the randomness of both spontaneous generations and spontaneous

productions.

It is not difficult to see how the examples of artificial productions that Aristotle provides

might fit the latter assumption. According to the interpretation in question, this passage allows that

while some artificial products, like a house, are always produced by synonymous causation, and

cannot be produced in any other way, others, like health, are produced by synonymous causation

only for the most part. The presence of a regular process that holds only for the most part is taken to

allow that sometimes – that is, exceptionally and unusually – the relevant results can be produced in

the absence of synonymous causation. When this happens, as when health is produced without the

action of a doctor, we should therefore speak of health as being produced ἀπὸ ταὐτομάτου. If then

this occurs in the case of natural generations just as it does in the case of artificial productions, we

would expect to find in nature not only creatures that are always born from other creatures of the

same nature, like men, but also some creatures that are born from other creatures of the same nature

only for the most part, creatures that can however sometimes – that is, exceptionally and unusually

– be generated not from a parent of the same nature.

However, this interpretation is hardly tenable. The fact of the matter is that in his analysis of

spontaneity in Metaphysics Z 7-9, Aristotle never claims that events occurring ἀπὸ ταὐτομάτου –

that is, in the absence of synonymous causation – occur irregularly, infrequently, exceptionally, or

‘neither always nor for the most part’. The only possible support for this reading comes from a

particular – and implausible – interpretation of the concluding and explanatory sentence of the

passage we are currently considering, in which Aristotle claims that in nature ‘ἔνια ταὐτὰ καὶ ἐκ

σπέρματος γίγνεται καὶ ἄνευ σπέρματος’. According to this particular interpretation, the sentence

could be read as stating that sometimes (ἔνια) – that is, neither always nor for the most part – the

same things (ταὐτὰ) that normally come to be ἐκ σπέρματος can come to be also ἄνευ σπέρματος.

This is the way in which Irwin and Fine interpret and translate this passage:

86

Things that come to be because of nature, then, come to be in this way. The other comings to be are

called productions; these are all from either craft or potentiality or thought. Some productions also

come to be from chance or luck, similarly to the way in which things come about from chance or

luck among things that come to be from nature; for in the latter case too the same things that

usually come to be from a seed also sometimes come to be without any seed.49

The particular grammatical construction that this interpretation of the text requires is not free from

serious difficulties. By taking the term ‘ταὐτὰ’ (‘the same things’) to be the subject of the sentence,

and by translating the term ‘ἔνια’ as an adverb (‘sometimes’), this construction does away with the

comparison that Aristotle seeks to establish between that which occurs by art and that which occurs

by nature. In the preceding clause of the Metaphysics, however, Aristotle claims that some (τινες) of

the things that are produced by art can also be produced spontaneously, without making any

reference to the alleged infrequency of spontaneous productions. It would seem only natural,

therefore, to take the term ‘ἔνια’ to be the subject of the clause that follows, which would thus be

interpreted as stating that in nature too some (ἔνια) living beings can be generated from seed as well

as without seed.

However, even if we were to set this problem aside and accept such a grammatical

construction, we could hardly interpret this passage as showing Aristotle’s commitment to the belief

in what Bostock calls “irregular and unusual generation, without seed, of animals that are

standardly generated from seed”,50

unless we interpret the term ‘ἔνια’ as an adverb of frequency

qualifying only cases of generation ἄνευ σπέρματος. Indeed, to make the text fit this assumption,

Irwin and Fine need to add to this passage a second, contrasting adverb (‘<usually>’) qualifying

cases of generation ἐκ σπέρματος so as to emphasize the alleged difference between the relative

regularity of that which comes to be ἐκ συνωνύμου and the exceptionality of that which comes to

be in the absence of synonymous causation. However, the addition of this second adverb is as

unjustified as is the restriction of the use of the term ‘ἔνια’ to cases of generation ἄνευ σπέρματος

49

IRWIN & FINE [1995], p. 287. 50

BOSTOCK [1994], pp. 138-139 (italics are mine).

87

and its interpretation as an adverb of frequency, for the original sentence does not underpin such a

contrast, nor can it be derived from the comparative analysis of artificial productions. The term

‘ἔνια’, if translated as an adverb, can only have a partitive meaning, with no bearing on the

frequency of generations ἄνευ σπέρματος.

There is, therefore, no clear or solid evidence that the Metaphysics endorses the belief in the

unusual generation without seed of plants and animals that are for the most part generated from

seed. Instead, this implausible interpretation of the passage suggests that the standard interpretation

of Metaphysics Z 7-9 is compromised by the unwarranted assumption that the absence of

synonymous causation is responsible for the randomness, infrequency, or irregularity of

spontaneous occurrences. Although Balme and other scholars insist that the Metaphysics offers a

‘sense’ or a ‘feeling’ of the spontaneous as unusual, exceptional, and random, there is in fact no

indication in the Metaphysics that Aristotle considers spontaneity as a random, irregular, infrequent,

or exceptional phenomenon.

To avoid these problems, some authors have claimed that the core idea of random

spontaneous generation is that what comes to be ἀπὸ ταὐτομάτου is something of the same sort as

that which comes to be also by virtue of a genuine teleological process, where the emphasis does

not fall on the alleged irregularity, rarity, or infrequency of spontaneous outcomes, but on the fact

that what comes to be ἀπὸ ταὐτομάτου is the same in species or form (τῷ εἴδει) as that which comes

to be either by art or by nature. In this way, random spontaneous generation, in its essence, is to be

interpreted primarily as the generation without seed of individual organisms belonging to species

whose members are generated also from seed.

Thus understood, the example of the spontaneous production of health given in Metaphysics

Z 7-9 would seem to lend support to the random spontaneous generation of living beings. Health is

something which can be produced by a genuine teleological process, that is, by a craft, which

Aristotle identifies with the εἶδος of health in the mind of the craftsman. Yet, the same εἶδος that the

88

craftsman brings about in a patient can also come to be ἀπὸ ταὐτομάτου. Hence, if the spontaneous

generation of living creatures happens just as the spontaneous production of health, spontaneity

would be seen as the mode of generation responsible for the birth of individual creatures belonging

to the same species of plants and animals whose members are also generated from seed. Apostle,

who favors this interpretation, translates the Metaphysics’ passage as follows:

This is the way, then, in which things are generated through nature, and the other generations are

called “productions”. All productions are generations by art, or by a power, or by thought. However,

some of these are also generations by chance or by luck, and in this manner they resemble the

generations by nature: for, among things generated, there are some which are the same <in species>,

whether generated from seed or without seed.51

Note that in this second translation of the text, the term ‘ἔνια’ is taken as the grammatical subject of

the clause and translated by the pronoun ‘some,’ with ‘ταὐτά’ as its predicate. This construction, as

we have seen, is perhaps less problematic than the one that takes ‘ταὐτὰ’ as the subject of the

sentence and ‘ἔνια’ as an adverb. However, even in this case, it is clear that the passage can hardly

prove Aristotle’s commitment to random spontaneous generation, unless we add, as Apostle does,

the qualification – also absent from the original text – that creatures that come to be without seed

are the same in species (ταὐτὰ <τῷ εἴδει>) as creatures that come to be from seed. Yet, there are

strong independent reasons why Aristotle cannot allow spontaneously generated creatures to be the

same in species as individuals that are generated from seed. Indeed, this is a possibility that he seeks

to exclude a priori, on the basis of a logical argument.

In the first pages of De Generatione Animalium, where Aristotle presents the problem of the

spontaneous generation of certain insects, spontaneously generated animals are defined as creatures

that come to be not from animals of the same kind, but from decomposing matter (ὅσα δὲ μὴ ἐκ

51

APOSTLE [1966], p. 117. Cfr. also REALE [2004], p. 313: “Anche in natura, certi esseri si generano in egual modo

sia dal seme sia senza seme” (italics are mine). Although Reale too construes ἔνια as the subject of the sentence, he

nevertheless presents a more ambiguous translation, which does not immediately appear to align with Ross’s

interpretation; however, in his commentary on this passage (p. 1030), it is clear that he understands it in exactly the

same way as Ross.

89

ζῴων ἀλλ’ ἐκ σηπομένης τῆς ὕλης).52

In this respect, De Generatione Animalium accords with the

analysis of the Metaphysics in defining spontaneity in terms of privation of synonymous causality.

The problem with interpreting the passage of Metaphysics Z 7 as accepting the theory of random

spontaneous generation is that if any spontaneously generated organisms belonged to the same

species as organisms that come to be from seed, then they should have the same form, and hence the

same nature, capacities, and faculties, as those that reproduce their own kind. But if they had the

same nature, capacities, and faculties as those that reproduce their own kind, then they would

themselves be able to give birth to animals of their own kind. This, according to Aristotle, is

impossible, because of the very definition of such creatures:

That this is so is reasonable (καὶ τοῦτο συμβέβηκεν εὐλόγως), for if those that do not come from

animals went on to produce themselves by coupling, then if the offspring were of the same kind (εἰ

μὲν ὁμογενῆ), the original generation of the parents ought also to have been produced in this way

(καὶ τὴν ἐξ ἀρχῆς τοιαύτην ἔδει τῶν τεκνωσάντων εἶναι γένεσιν). This is a reasonable claim (τοῦτο

δ’ εὐλόγως ), for it is what we see happening in the other animals (φαίνεται γὰρ συμβαῖνον οὕτως ἐπὶ

τῶν ἄλλων ζῴων).53

In this passage, Aristotle aims to provide a logical proof in order to show the reasonableness

(εὐλόγως) of the phenomena that we observe in the natural world. What is apparent (φαίνεται) in

nature is that “all animals that come from coupling of animals of their own kind (ὅσα μὲν ἐκ

συνδυασμοῦ γίγνεται τῶν συγγενῶν ζῴων) also generate according to their kind (καὶ αὐτὰ γεννᾷ

κατὰ τὴν συγγένειαν)”.54

But this is not what we see happening with animals that are spontaneously

generated, that is, animals that do not come to be from animals of the same kind, and this is

reasonably so; for if they did, then they would give birth to animals of the same kind (ὁμογενῆ), and

this would contradict the very definition of their kind.

52

De Gen. An. I 1, 715b 4-5. 53

De Gen. An. I 1, 715b 7-12. 54

De Gen. An. I 1, 715b 2-4.

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This argument is modeled on the ἀπόδειξις λογική provided by Aristotle in De Generatione

Animalium II 8 to explain the sterility of mules.55

The argument can be summarized as follows: the

mule is by definition the product of two different species, namely the horse and the ass, which

means that it does not come to be ἐξ ὁμοειδῶν. It is therefore impossible that mules generate mules,

because in that case they would come to be ἐξ ὁμοειδῶν, which contradicts the original definition.

In the case of spontaneously generated creatures, what this argument shows is that Aristotle

is committed to the idea that animals that are spontaneously generated are different in species

(ἕτερα τῷ εἴδει) from those that are naturally reproduced. This means that, in biology, what comes

to be spontaneously is not and cannot be something of the same species as that which comes to be

by nature.

This conclusion is particularly important because it shows us that if spontaneously

generated creatures cannot be the same in form as those which come to be by nature, then we

should also reject the assumption that the spontaneous generation of living creatures occurs just as

the spontaneous production of health, in other words, we should deny that spontaneous generations

and spontaneous productions are two specific instantiations of one and the same general

phenomenon.

Indeed, Aristotle does not claim that spontaneous generations and spontaneous productions

happen in the same way, and we should remain cognizant of the fact that he does not seek to make

this point at all. Almost all translators and commentators of the passage above of the Metaphysics Z

7 have overlooked this important detail. Ross, as we have seen, translates the statement in which

Aristotle indicates the crucial junction between art and nature as saying that “among products of art

some happen also spontaneously or by chance just as natural products sometimes do”. The text,

however, makes it clear that what occurs ἀπὸ τοῦ αὐτομάτου in artificial productions does not occur

55

Cfr. De Gen. An. II 8, 747b 27 ss. For an interesting discussion on this passage and the ‘empty talk’ (κενολογεῖν) of

this mode of argumentation in biology cfr. VEGETTI [2007], pp. 145-149.

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‘just as’ it does in natural generations, but only ‘παραπλησίως ὥσπερ ἐν τοῖς ἀπὸ φύσεως

γιγνομένοις’, that is, almost or nearly like it occurs in natural generations.

The phenomenon of spontaneity in the sphere of human productions, then, is not placed at

the same level as the phenomenon of spontaneity as it appears in natural generations, for it does not

simply happen ‘just as (ὥσπερ)’ it happens for living creatures. Rather, the relationship between

spontaneity in artistic productions and spontaneity in natural generations is presented as a

resemblance or likeness (παραπλησίως ὥσπερ), in much the same way in which synonymous

causation in artistic productions is said to happen only ‘in a way (τρόπον τινά)’ as it happens in

natural generations. Indeed, such a relationship appears to be conceived in the same way as

Aristotle generally conceives the relationship between art and nature, that is, in the form of an

analogy. It is instructive to see that the expression ‘παραπλησίως ὥσπερ’ is consistently used by

Aristotle precisely with a view to illustrate the analogical relationship between nature and art. In De

Generatione Animalium, for instance, Aristotle claims that “the material secreted by the female in

the uterus is congealed by the semen of the male, which acts almost like (παραπλήσιον ὥσπερ)

rennet acts upon milk”.56

Similarly, in De Generatione et Corruptione, Aristotle claims that those

who hold that matter, by virtue of its own motions, is adequate to account for the generation of

natural beings, do not see that by omitting the formal cause from their explanations, they “proceed

almost as if (παραπλήσιον ὥσπερ) one were to treat the saw and the various instruments of

carpentry as the cause of the things that come to be”.57

It is clear, then, that the alleged endorsement of random spontaneous generation in the

Metaphysics is anything but straightforward, and depends on interpretative assumptions which are

without any textual foundation. None of the elements in Metaphysics Z 7-9 justify the assumption

that Aristotle regards spontaneity as an irregular and unusual phenomenon. In addition, Aristotle

56

De Gen. An. II 4. 57

De Gen. et Corr. II 9, 336a 7-9. Similarly, in De An. I 3, 24-25, Aristotle states that those who, like the Pythagoreans,

claim that any random soul can go into any random body, “speak nearly as if (παραπλήσιον ὥσπερ) one were to say that

the art of carpentry could embody itself in flutes”.

92

makes it clear that the spontaneous generation of living beings does not occur in the same way as

the spontaneous recovery of health, but that the two phenomena are only similar by virtue of

analogy. Finally, the belief that spontaneously generated creatures belong to the same species of

plants and animals whose members are generated from seed is regarded by Aristotle as being not

only in conflict with what he took to be empirical evidence, but also, and more importantly, as

impossible on purely logical grounds.

Hence, far from there being evidence that the biological works contradict Metaphysics Z 7-

9, a careful analysis of that text, backed by compelling evidence from the biological works, reveals

that Aristotle’s biological works contradict only the standard interpretation of Metaphysics Z 7-9,

and the particular assumption on which this interpretation rests. Therefore, if we can find an

alternative interpretation of this passage, one both in line with the claims made in Metaphysics Z 7-

9 and supported by independent evidence from Aristotle’s biological works, we can reasonably

conclude that there is no inconsistency between the account of spontaneity presented in

Metaphysics Z 7-9 and Aristotle’s treatment of spontaneously generated creatures in the biological

works.

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3. Regular Spontaneous Generation in Metaphysics Z 7-9: An Alternative Interpretation

By extending our research to the study of spontaneous generation in the Historia Animalium and De

Generatione Animalium, we find considerable evidence in support of an alternative reading of

Metaphysics Z 7, one according to which there is no incompatibility between the account of

spontaneity presented in Metaphysics Z 7-9 and the treatment of spontaneously generated creatures

in the biological works.

The crux of the problem, as we have seen, lies in the interpretation of Aristotle’s claim that

among living beings, ‘ἔνια ταὐτὰ καὶ ἐκ σπέρματος γίγνεται καὶ ἄνευ σπέρματος’. All those who

claim that in this statement Aristotle endorses a theory of random spontaneous generation assume

that the creatures which are generated ἄνευ σπέρματος are the same in species (<τῷ εἴδει> ταὐτά) as

those generated ἐκ σπέρματος. This assumption, however, contradicts what Aristotle holds in his

biological works – it is not only incompatible with what he takes to be observable facts, but also,

and more significantly, logically inconsistent on purely speculative grounds – and in the absence of

independent reasons for holding this interpretation, it ought to be rejected.

Instead, we should interpret this passage as saying that the same things that are generated

both ἐκ σπέρματος and ἄνευ σπέρματος are only ‘the same in kind (<τῷ γένει> ταὐτά)’. In this way,

the term ‘ἔνια’ – whether it is translated as a partitive adverb or, as it is more likely, as the subject

of the sentence – would single out groups of organisms that although identical in kind are different

in species (ἕτερα τῷ εἴδει) according to their mode of generation. Thus understood, the passage in

Metaphysics Z 7 finds significant support in the biological writings, where there is plenty of

evidence of precisely such a formulation of the theory of spontaneous generation, and it helps us to

ascertain that Aristotle regards the spontaneous generation of living beings as only analogous to the

spontaneous recovery of health.

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In examining the biological works, we should begin by noting that the pronoun ‘ἔνια’ is

generally used by Aristotle not to identify some individual organisms within the same species of

creatures, as it is assumed in the standard interpretation of the Metaphysics, but rather to single out

individual organisms belonging to the same general kind of creatures, yet forming separate and

distinct species. This peculiar use of the pronoun ‘ἔνια’ may be the source of some confusion. Many

scholars, as we have seen, have described the spontaneous generation of living beings in Aristotle’s

biological works as the generation without seed of entire species of animals.58

As previously noted,

this way of describing regular spontaneous generation is misleading, since Aristotle does not

believe that species can be generated: generation, whether from seed or without seed, is always the

generation of particular living creatures, not species. Although those who describe regular

spontaneous generation as the generation without seed of entire species clearly mean that it is the

individual members of the relevant species – and not the species themselves – that are generated, it

is particularly important to bear in mind their incorrect formulation of the theory of spontaneous

generation, as it will provide the key to understanding and resolving the apparent conflict in

Aristotle’s account of τὸ αὐτόματον.59

For the time being, however, we should simply note that this incorrect formulation of the

theory of regular spontaneous generation is likely derived from a misconstruction of Aristotle’s own

use of the pronoun ‘ἔνια’. The fact is that Aristotle consistently uses the pronoun ‘ἔνια’ to draw a

distinction between creatures belonging to species whose members are always spontaneously

generated and those belonging to species whose members are always generated from seed; and it is

58

Cfr. Part I, Chapter 2; for instance BOSTOCK [1994], p. 139, who claims that in De Generatione Animalium

Aristotle endorses the belief in the “the regular generation of certain species of animals without seed”; HULL [1967-

1968], p. 247, who speaks of Aristotle’s belief in “species which are generated spontaneously;” LENNOX [1982], p.

220, who claims that “in the Generation and History of Animals, Aristotle argues that entire genera are generated ἀπὸ

τοῦ αὐτομάτου;” GOTTHELF [1989], p. 190, who points out that “even some blooded animals, such as the eel and

some species of river fish, are generated spontaneously;” and JOHNSON [2012], p. 118, for whom “some kinds of

organisms, admittedly very lowly ones, can in fact regularly be generated spontaneously”. 59

Cfr. Part II, Chapter 9.

95

only through a synecdoche – that is, by using a term that denotes individual members of a certain

species to refer to the species itself – that we can speak of ‘spontaneously generated species.’

We have already encountered an example of such use of the pronoun ‘ἔνια’ in Aristotle’s

consideration of plants.60

In the opening chapter of De Generatione Animalium, right after

providing the logical argument for the observable fact that no animal that is spontaneously

generated can give birth to an animal of the same species – for if it did, that would contradict the

very definition of its species – Aristotle claims:

The same holds good also in plants (ἐπὶ τῶν φυτῶν), for some come into being from seed (τὰ μὲν γὰρ

ἐκ σπέρματος γίγνεται) and others, as it were, by the spontaneous action of nature (τὰ δ’ ὥσπερ

αὐτοματιζούσης τῆς φύσεως), arising either from decomposition of the earth or of some parts in

other plants; some (ἔνια), in fact, are not formed separately by themselves, but are produced upon

other trees, as the mistletoe.61

It is clear, from the example provided at the end of this passage, that when Aristotle says that ‘some

plants are not formed separately by themselves’, the pronoun ‘ἔνια’ is not used to refer to individual

creatures belonging to the same species of plants whose members are usually generated from seed,

for that would imply random spontaneous generation. Nor, strictly speaking, does the term ‘ἔνια’

stand for species of plants within the same kind, for that would imply the generation of entire

species of living beings. Rather, ‘ἔνια’ is used to identify individual plants that are different in

species from those which are generated from seed. Indeed, this passage is meant to confirm the fact

that no living creature spontaneously generated can possibly be the same in species (τῷ εἴδει ταὐτά)

as those that come to be from seed, for if they did share the same εἶδος, they would also share the

same φύσις, which is impossible – hence the observation that such creatures do not come to be by

nature (φύσει), but ‘as it were, from a spontaneous action of nature (ὥσπερ αὐτοματιζούσης τῆς

φύσεως)’.

60

Cfr. Part I, Chapter 2. 61

De Gen. An. I 1, 715b 25 – 716a 2.

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The same use of the term ‘ἔνια’ is again employed by Aristotle in his discussion about another

major kind of living beings in which we find creatures generated both from seed and without seed,

namely insects.

Among bloodless animals the insects produce a grub, both those that are generated by copulation and

those that themselves copulate. For among insects (τῶν ἐντόμων) there are some (ἔνια) of such sort

that they come into being by spontaneous generation, yet they are male and female, and from their

union an animal is produced, only it is imperfect.62

Once again, the fact that the pronoun ‘ἔνια’ refers to individual creatures forming distinct and

separate species within the broader kind of insects (τῶν ἐντόμων), and not to a group of individuals

within the same species of insects, is confirmed through examples that Aristotle provides in a

parallel passage from the first book of De Generatione Animalium where he presents a threefold

classification of insects:

Among insects (τῶν ἐντόμων), some (τὰ μὲν) copulate and the offspring are produced from animals

of the same name (ἐκ ζῴων συνωνύμων), just as with the blooded animals; such are the locusts,

cicadae, spiders, wasps, and ants. Others (τὰ δὲ) unite indeed and generate; but the result is not a

creature of the same kind, but only a grub (οὐχ ὁμογενῆ δ’ αὑτοῖς ἀλλὰ σκώληκας μόνον), and these

insects do not come into being from animals but from putrefying matter, liquid or solid; such are

fleas, flies, and cantharides. Others again (τὰ δ’) are neither produced from animals nor unite with

each other; such are gnats, mosquitoes, and many similar kinds.63

The intent of this classification, reiterated in many different passages of the biological treatises, is to

show that creatures belonging to one and the same γένος of living beings, namely insects, can come

to be both from parents of the same kind – that is, from synonymous causation, as it is expressed in

the Metaphysics – and from spontaneous generation – that is, in the absence of synonymous

causation – as a similar passage of De Generatione Animalium also indicates:

62

De Gen. An. II 1, 732b 10-14. Note that, as shown in the next quote, the imperfection of a creature born from

spontaneously generated insects is a matter of the offspring not being the same in kind (ὁμογενῆ) as the parents (cfr.

also Part I, Chapter 4). 63

De Gen. An. I 16, 721a 2-10.

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Insects, both those which generate a grub (καὶ γεννᾷ τὰ γεννῶντα σκώληκας) and those which come

into being spontaneously and not from copulation (καὶ τὰ γιγνόμενα μὴ δι’ ὀχείας ἀλλ’ αὐτόματα),

come to be first from a formation of this sort (ἐκ τοιαύτης γίγνεται πρῶτον συστάσεως).64

As we can see, it is very common for Aristotle to claim that some creatures, like insects, can be

generated both spontaneously and from copulation; and, just as it would be a mistake to interpret

such claims as speaking of the spontaneous generation of individual insects belonging to species

whose members can be generated also from copulation, so too it would be an error to interpret the

Metaphysics’ claim as defending the belief in the generation without seed of individual organisms

belonging to species whose members can be generated also from seed.

The most interesting biological examples of the ideas expressed in the Metaphysics,

however, come from Aristotle’s consideration of spontaneously generated fishes. These examples

are interesting not only because they are closely related to the ideas put forth in the Metaphysics and

help us to clarify the origins and the doctrines of the theory there endorsed, but also because they

are mostly taken from the Historia Animalium, which Balme considers to be scientifically,

theoretically, and doctrinally more distant from the Metaphysics than De Generatione Animalium is.

In Book VI of the Historia Animalium, for instance, Aristotle claims that:

As we have said, the greatest number of fish (οἱ μὲν οὖν πλεῖστοι τῶν ἰχθύων) is born from eggs;

however, even among those kinds that reproduce from copulation and eggs (καὶ τῶν τοιούτων γενῶν

ἃ γίνεται ἐκ συνδυασμοῦ καὶ ᾠῶν), there are some (ἔνιοι) that are generated also (καὶ) from mud and

sand.65

Taken on its own and out of context, this passage presents ambiguities almost identical to those of

Metaphysics Z 7. Here too, one may wrongly be led to believe that Aristotle is speaking of the

generation out of mud and sand of exceptional specimens (ἔνιοι) of fish belonging to the species

(τῶν τοιούτων γενῶν) whose members are for the most part (οἱ πλεῖστοι) reproduced through

copulation. This interpretation, however, betrays a deep misunderstanding of Aristotle’s meaning.

64

De Gen. An.III 9, 758b 6-9. This is important for his reflections on the possibility of spontaneous generation of

humans and other quadrupeds, which he considers in De Gen. An.III 11, 762b 29 ff. 65

Hist. An. VI 15, 569a 10-13.

98

To be sure, we have seen that the notion of ‘γένος’ has a flexible meaning in Aristotle’s

biological works: it can be used to designate either a genus or a species.66

So this passage might be

interpreted as endorsing the belief in the random spontaneous generation of fishes if ‘γένη’ were

being used here to designate species. But this interpretation ought to be rejected. The ambiguity of

the passage is resolved once we consider the examples that follow, which Aristotle uses to illustrate

his claim:

This occurs generally in marshy places, as for example in a pond which is said to have once

surrounded Cnidos. This pond became dry during the dog-days (ὑπὸ κύνα), and the mud was all

taken out; but with the first fall of the rains there was a show of water in the pond, and on the first

appearance of the water tiny fishes appeared in the pond. The fish in question was a kind of mullets

(κεστρέων τι γένος), one which does not proceed from normal pairing, about the size of a small

sprat, and none of these fishes (τούτων οὐδὲν) was provided with either egg or milt.67

It is clear, then, that in the preceding passage Aristotle uses the term ‘γένος’ not to refer to a species

of fish, as he would be if he were talking about random spontaneous generation, but to refer to a

genus of fishes; hence, he is evidently speaking of regular spontaneous generation. An example of

such γένη of fishes in fact are mullets, which Aristotle, in the passage above, claims to be composed

of different γένη, that is, of different species, one of which is such that all of its members are

spontaneously generated.68

Note that this is not the only example Aristotle provides of a γένος of

fishes whose specimens can be generated ‘both from copulation and eggs and from mud and sand’;

for, some lines further, he mentions that some specimens “of the small fry (τῆς ἀφύης)” are also

spontaneously generated, like “the so-called froth (ὁ καλούμενος ἀφρὸς), which comes out of sandy

grounds”.69

It is apparent that the individual specimens “of the small fry (τῆς ἀφύης)” which are

spontaneously generated form an independent species of fishes within a broader genus, and hence,

66

Cfr. Part I, Chapter 7. 67

Hist. An. VI 15, 569a 13-19. 68

Cfr. the very similar passage in Hist. An. IV 2, 525a 30 – 525b1: “With regard to the crustaceans, one genus (γένος) is

that of the crayfish, and a second, resembling the first, is that of the lobster; the lobster differing from the crayfish in

having large claws, and in a few other respects as well. Another kind is that of the carid, and another is that of the crab,

and there are many species (γένη) both of carid and of crab.” 69

Hist. An. VI 15, 569a 29.

99

that Aristotle is speaking of the regular spontaneous generation of fishes, even though the

ambiguity of the expressions he uses could be misinterpreted as implying random spontaneous

generation.

Therefore, when Aristotle claims that ‘even among those kinds (καὶ τῶν τοιούτων γενῶν) of

fishes that are generated from copulation and egg there are some (ἔνιοι) that are generated also (καὶ)

from mud and sand’, he means to say that there are some genera of fishes which include both (καὶ)

species whose members always reproduce from copulation and egg and (καὶ) species whose

members are always generated from mud and sand. Clearly, as we have seen, if there is any ‘sense’

or ‘feeling’ that the spontaneous generation of fishes is ‘unusual’, it is only in the equivocal sense,

that the majority of species of fishes (οἱ πλεῖστοι τῶν ἰχθύων) are such that their members

reproduce from copulation and egg, while only a few species (ὀλίγοι) are such that their members

are generated from mud and sand.70

Hence, just as it would be an error to interpret the Historia

Animalium as speaking of the unusual generation out of mud and sand of individual specimens of

fish belonging to species whose members are normally reproduced from copulation and egg, so too

it is an error to interpret the Metaphysics as speaking of the unusual generation without seed of

individual organisms belonging to species whose members are normally reproduced from seed, that

is, of random spontaneous generation.

The case of mullets is particularly relevant to understanding Aristotle’s point of view. In a

passage of Book VI of the Historia Animalium, Aristotle claims that “some mullets (ἔνιοι τῶν

κεστρέων) are not born from copulation, but grow (φύονται) from mud and sand.”71

This sentence,

taken in isolation, might lead us to think that Aristotle is speaking of the random spontaneous

generation of mullets. Again, this would be a serious misinterpretation of the text, as Aristotle

considers mullets as a genus of fishes which include different species. To fully understand the

70

Cfr. Part I, Chapter 3. 71

Hist. An. V 11, 543b 17-18. Curiously the expression here used to indicate spontaneous generation is simply the verb

φύεσθαι, ‘to spring forth’, generally used for plants. This use is quite common in Aristotle; cfr. for example Hist. An. VI

15, 569a 21-22.

100

significance of what Aristotle is saying, we need to appreciate the polemical context in which he

makes his remarks. Aristotle is in fact addressing the belief of some people, presumably fishermen,

who believed that all mullets, without exception, are spontaneously generated.

Some claim that all mullets grow spontaneously, but those who say this are incorrect; for the female

of the fish is found provided with eggs, and the male with milt. However, there is a kind of mullet

that grows out of mud and sand (ἀλλὰ γένος τί ἐστιν αὐτῶν τοιοῦτον, ὃ φύεται ἐκ τῆς ἰλύος καὶ τῆς

ἄμμου).72

Because of their insufficient observation of the internal organs of these fish, fishermen believe that

mullets form a species of fish whose specimens are all spontaneously generated. Aristotle rebuts

this claim by pointing out, on the basis of empirical evidence, that some mullets are in fact provided

with eggs and milt, while others are not, and hence concludes that only some (ἔνιοι) of them are

spontaneously generated, growing out of mud and sand.

Note that, as a result of these observations, Aristotle concludes not that the mullets that grow

out of mud and sand are spontaneously generated specimens of the same species as those that are

provided with eggs and milt and reproduce from copulation, but rather that they form a different

kind of mullets (κεστρέων τι γένος).73

This is to be expected, as the logical argument from De

Generatione Animalium shows, for if they do not come to be ἐκ ζῴων συγγενῶν – that is, if they do

not come from animals of that kind – they cannot possibly be specimens of that kind.

According to Aristotle, the different forms of generation characteristic of different

specimens of mullets provide sufficient reason to deny them a common nature, and hence to

exclude the possibility that they form a unitary species. Instead, he simply claims that they have a

set of common features, and thus, a generic unity, which is differentiated precisely by their

72

Hist. An. VI 15, 569a 21-25. 73

Hist. An. VI 15, 569a 17-19. Note that here the term γένος refers to ‘species’. This may be a typical example of the

flexible language of the Historia Animalium, as noted by BALME [1962a] and VEGETTI [1971]; alternatively,

Aristotle may be using γένος rather than εἶδος because he thinks that spontaneously generated creatures do not belong

to species in the strict sense of the term.

101

distinctive modes of generation. On these premises, then, Aristotle concludes the investigation on

the generation of fishes by stating that:

From the facts above enumerated it is clear that some fish come into existence spontaneously

(γίνεται αὐτόματα ἔνια), not being derived either from eggs or from copulation. Such fish as are

neither oviparous nor viviparous arise all either from mud or from sand and from decayed matter that

rises thence as a scum.74

Aristotle formulates the same view in another crucial passage of Book V of the Historia Animalium,

which so closely resembles the claim that he makes in the Metaphysics that it appears to provide

precisely the missing evidence in support of that claim.

In animals where generation takes place from animals of the same kind (ἀπὸ συγγενῶν ζῴων),

wherever there is male and female, generation is due to copulation. Within the kind of fishes (ἐν τῷ

τῶν ἰχθύων γένει), however, there are some (ἔνια) that are generated (γίνεται) neither male nor

female, and these, while they are identical in kind (τῷ γένει μὲν ὄντα τὰ αὐτά) with other fishes,

differ from them according to their species (τῷ εἴδει δ’ ἕτερα).75

According to this passage, animals that present sexual dimorphism come to be from animals of the

same species through the copulation of the two sexes; and yet, within the kind of fishes, there are

some (ἔνια) that, though they are the same in genus (τῷ γένει τὰ αὐτά ὄντα) as other fishes, differ

from them in species (τῷ εἴδει δ’ ἕτερα), since they do not present sexual dimorphism, and hence,

do not come to be (γίνεται) through copulation. But this means that in nature, some creatures,

though the same in all other respects, may come to be both from copulation and without copulation.

This, however, does not allow us to infer that they belong to the same species; on the contrary, this

proves that their identity is only generic (τῷ γένει τὰ αὐτά), and that they belong to different species

(τῷ εἴδει δ’ ἕτερα).

As we can see, the formulation of this passage corresponds almost literally to Aristotle’s

claim in the Metaphysics. There, too, Aristotle claims that in nature ‘ἔνια ταὐτὰ καὶ ἐκ σπέρματος

74

Hist. An. VI 15, 569a 25-28. 75

Hist. An. V 1, 539a 25-30: “Τῶν δὴ τὴν γένεσιν ἐχόντων ἀπὸ συγγενῶν ζῴων ἐνοἷς μὲν αὐτῶν ἐστι τὸ θῆλυ καὶ τὸ

ἄρρεν, ἐκ συνδυασμοῦ γίνονται· ἐν δὲ τῷ τῶν ἰχθύων γένει ἔνια γίνεται οὔτ’ ἄρρενα οὔτε θήλεα, τῷ γένει μὲν ὄντα

ἑτέροις τῶν ἰχθύων τὰ αὐτά, τῷ εἴδε δ’ ἕτερα.”

102

γίγνεται καὶ ἄνευ σπέρματος’. Balme, in his comment on this passage, states that there is no

evidence in Aristotle’s biology of the sort of spontaneously generated animals described in the

Metaphysics.76

The Historia Animalium passage, however, proves that Balme is wrong, and that his

claim depends entirely on his incorrect interpretation of the Metaphysics’ description of

spontaneously generated animals. The underlying assumption of Balme’s interpretation, and that of

the majority of scholars who agree with him, is that the creatures that come to be spontaneously

must be particular creatures, identical in species (ταὐτὰ <τῷ εἴδει>) to creatures that come to be

from seed. This, however, is a mistaken assumption, one which Aristotle believed to be in conflict

with the empirical findings of his biological research and logically inconsistent from a purely

theoretical point of view.

Far from there being any doctrinal inconsistency between the so called ‘theoretical’ analysis

of spontaneity in the Metaphysics and the ‘biological’ account of Historia Animalium and De

Generatione Animalium, all the evidence indicates instead that the account of spontaneity in the

Metaphysics derives from, and rests upon, the observation and study of spontaneous generation in

the Historia Animalium and De Generatione Animalium, which show that the assumption implicit

in the Metaphysics’ passage is that spontaneously generated creatures are same only in genus (τῷ

γένει τὰ αὐτά) to creatures that come to be from seed. Thus, based on the evidence from his

biological studies on the generation of living beings, we deduce that when Aristotle in the

Metaphysics claims that in nature ‘ἔνια ταὐτὰ καὶ ἐκ σπέρματος γίγνεται καὶ ἄνευ σπέρματος’, he

means to say that in nature ‘some things, while being the same in genus (τῷ γένει ὄντα ταὐτὰ),

come to be both from seed and without seed’.

The things that may come to be both from seed as well as without seed, therefore, are not

specimens of one and the same species of living beings – they are not τῷ εἴδει ταὐτά. In the

zoological treatises, in fact, Aristotle makes it clear that both reason and experience show that ‘the

76

Cfr. BALME [1962], p. 97.

103

same things’ that can come to be both from seed and not from seed are necessarily τῷ εἴδει ἕτερα.

This explains why in Metaphysics Z 7-9, Aristotle emphasizes the fact that what occurs ἀπὸ τοῦ

αὐτομάτου in artificial productions, occurs ‘almost as it occurs in natural generations (παραπλησίως

ὥσπερ ἐν τοῖς ἀπὸ φύσεως γιγνομένοις)’. This is because spontaneous generations are only

generically the same as natural generations, at a level which is superior to and inclusive of the

different particular species, whereas spontaneous productions are specifically the same as artificial

productions.

In studying the passages on spontaneous generation in Aristotle’s Metaphysics, and

comparing them with the numerous examples of spontaneous generation in his biological works, we

glean that the reference to spontaneous generation in the Metaphysics provides an almost verbatim

account of the beliefs expressed in Historia Animalium. Thus, it is reasonable to deduce that, far

from presenting discordant views, the biological examples of Historia Animalium V and VI are

actually the source of the account presented in Metaphysics Z 7-9,77

and hence that they provide us

with the key to understanding the challenging and controversial passage of Metaphysics Z, for

which no satisfactory interpretation has yet been proposed.

77

There is also something objectionable about Balme’s belief that the Metaphysics relies on “general knowledge” of

biology gained from “popular medicine and agriculture” (BALME [1962], p. 97.) and not on the scientific material of

‘his own biological works’. Indeed, as far as the theory of spontaneity in the biological works is concerned, Aristotle

draws his information from the ‘general knowledge’ of farmers, fishermen, and practitioners of the other arts, and none

of these sources accept random spontaneous generation (cfr. Part II, Chapter 8).

104

4. Spontaneity in Physics B 4-6: The Standard Interpretation

As we have seen, scholars who claim that Aristotle endorses a theory of random spontaneous

generation in the Metaphysics base their reasoning on interpretative assumptions that are

unwarranted and without textual foundation. There is nothing in Metaphysics Z 7-9 that justifies the

assumption that spontaneity is an irregular and unusual phenomenon, or the assumption that it is

responsible for the generation of creatures belonging to the same species of plants and animals

whose members are generated also from seed. Such assumptions are not only in conflict with what

Aristotle took to be empirical data concerning the spontaneous generation of living beings, but also

inconsistent from a purely theoretical point of view. Hence, in looking at Aristotle’s account of

spontaneity in the Metaphysics in its own merit, and his corresponding treatment of spontaneous

generation in the biological works, we should conclude that there is no inconsistency between the

so-called ‘theoretical’ and ‘biological’ accounts of spontaneous generation.

To get a better grasp of the reasons that have led so many scholars to attribute such an

inconsistency to Aristotle, we ought to examine the source of the misleading interpretative

assumptions underlying the standard interpretation of the Metaphysics. In order to supply those

assumptions, Aristotelian scholars have turned to Aristotle’s analysis of τὸ αὐτόματον and τύχη in

Physics B 4-6. Indeed, the view that Metaphysics Z 7-9 endorses a theory of random spontaneous

generation rests precisely on the unchallenged belief that Aristotle’s account of spontaneity in the

Metaphysics corresponds with and builds upon his analysis of τὸ αὐτόματον in the Physics B 4-6 –

hence the idea that these two works present a unitary and univocal ‘theoretical’ account of

spontaneity inconsistent with the ‘biological’ account in his biological works. However, given that

our closer analysis of the Metaphysics has revealed that there is no contradiction with the biological

works, the alleged correspondence between the account of spontaneity in Metaphysics Z 7-9 and the

analysis of τὸ αὐτόματον in Physics B 4-6 becomes precisely the point of dispute.

105

In order to clarify the relationship between these two texts, we must therefore consider the

analysis of τὸ αὐτόματον in Physics B 4-6 and the particular interpretation that leads commentators

to conclude that this text implies the theory of random spontaneous generation. By exposing the

assumptions behind the standard reading of Physics B 4-6 and the commonly held view of its

correspondence with Metaphysics Z 7-9, we may arrive at a diagnosis of the misreading that leads

commentators to believe in a unified ‘theoretical’ account of random spontaneous generation

incompatible with the ‘biological’ account of regular spontaneous generation in the zoological

works.

The view that the account of spontaneity in the Metaphysics corresponds with and builds

upon the analysis of τὸ αὐτόματον in the Physics rests on the widely held opinion that in Physics B

4-6, Aristotle draws a distinction between a generic and specific sense of ‘τὸ αὐτόματον’. Ross, for

instance, claims that in the Physics, “τὸ αὐτόματον has a specific usage in which it stands for

something different from τύχη, and a generic usage in which it includes both τύχη and τὸ

αὐτόματον in the specific sense”.78

Similarly, Frede and Patzig have claimed that “in Aristotelian

usage, ‘spontaneity’ is the generic term that includes both chance and spontaneity in a narrower

sense, namely the spontaneous which is not by chance”.79

The same point is made by Allen, albeit

with a different translation of the terms in question, as he claims that “‘chance’ stands in for the

genus designated αὐτόματον by Aristotle, which he divides into two species, τύχη, luck or fortune,

which is operative in the realm of practice, and its counterpart in the natural world, the automatic or

spontaneous, called like the genus, αὐτόματον”.80

This view has been summarized by Rossi in her

monograph on Aristotle’s theory of chance:

Although Aristotle does not state it explicitly, it seems clear that we should suppose that spontaneity

as a genus includes not only luck, but also everything which, being spontaneous, is not by luck. Such

78

ROSS [1936], p. 38 (italics are mine). 79

FREDE & PATZIG [1988] (vol. II), pp. 111-112: “Wie wir bereits bemerkt haben, ist nach aristotelischem

Sprachgebrauch ‘Spontaneitat’ der Oberbegriff, der sowohl den Zufall als auch die Spontaneitat in einem engeren Sinn

umfaßt, nämlich das Spontane, das nicht zufällig ist” (italics are mine). 80

ALLEN [2015] (italics are mine).

106

a complementary class, which is also called ‘spontaneity’, cannot be identified with the genus,

despite its homonymy. We can therefore speak of spontaneity in a generic sense (which corresponds

to what we have hitherto called ‘chance’ and continue to call thus to avoid confusion) and

spontaneity in a specific sense.81

Despite the widespread agreement that τὸ αὐτόματον has both a generic and a specific sense,

scholars disagree widely on the translation of the terms involved in Aristotle’s analysis.82

To avoid

any confusion, we shall use the more traditional translation ‘chance’ for the generic sense of τὸ

αὐτόματον, ‘luck’ for τύχη, and ‘spontaneity’ for what is thought to be the specific sense of τὸ

αὐτόματον. In spite of the problems and differences in translation, the key point of the alleged

genus-species homonymy of τὸ αὐτόματον is the idea that spontaneity, just as luck, is a specific

instance of the general phenomenon of chance – hence the idea that the spontaneous generation of

living beings as presented in the Metaphysics is a case of chance generation.83

We ought to begin by noting, however, that throughout Chapters 4 and 5 of Physics B,

Aristotle uses both the term ‘τύχη’ and ‘τὸ αὐτόματον’ to refer to the general phenomenon of

chance – suggesting that the term ‘τύχη,’ in a way, is also used in both a generic and a specific

sense.84

This point is particularly significant, as we shall see, to understanding Aristotle’s dialectical

survey of the most important and reputable opinions concerning the phenomenon of chance in

Chapter 4, as it provides the key to resolving the question of homonymy of the term ‘τὸ

αὐτόματον’.85

For the time being, however, we should focus on the way in which Aristotle defines

chance in Chapter 5, and how commentators have been led to distinguish between a generic and a

81

ROSSI [2011], p 238: “Si bien Aristoteles no lo afirma explícitamente, parece claro que hay que suponer que la

espontaneidad como género incluye no sólo a la fortuna, sino también a todo aquello que, siendo espontaneidad, no es

por fortuna. Esa suerte de clase complementaria, que tambien es llamada ‘espontaneidad’, no puede identificarse sin

embargo con el género, a pesar de la homonimia con el mismo. Podemos hablar, pues, de espontaneidad en sentido

genérico (la cual corresponde a lo que hasta ahora hemos llamado ‘azar’ y que seguiremos denominando de este modo

para evitar confusiones) y espontaneidad en sentido específico” (italics are mine). 82

Some authors, like ROSS [1936], p. 38, propose to translate τὸ αὐτόματον in the specific sense as ‘randomness’;

CHARLTON [1970], p. 105, fearing that ‘spontaneity’ suggests acting out of free will, uses the term ‘automatic’. For a

review of the most common translations of the terms τὸ αὐτόματον and τύχη in English, cfr. GUTHRIE [1981], pp.

235-236, and DUDLEY [2012], pp. 175-176. For a more general perspective on the different translations in modern

literature, cfr. GIARDINA [2006], pp. 187-189. 83

Cfr. JUDSON [1991], p. 74. 84

Cfr. Phys. B 4, 195b 34-35, and B 5, 196b 31-33. 85

Cfr. Part II, Chapter 7.

107

specific sense of τὸ αὐτόματον, and thereby establish correlations between Physics B 4-6 and

Metaphysics Z 7-9.

As we have seen,86

Aristotle develops his positive account of chance at the beginning of

Physics B 5 by appeal to two criteria. Firstly, he claims that τύχη and τὸ αὐτόματον are causes of

things that come to be “neither by necessity and always, nor for the most part (οὔτε τοῦ ἐξ ἀνάγκης

καὶ αἰεὶ οὔτε τοῦ ὡς ἐπὶ τὸ πολύ)”.87

Secondly, he claims that τύχη and τὸ αὐτόματον are

responsible for things “such as might come to be for the sake of something (ὅσ’ ἂν γένοιτο ἕνεκά

του)”.88

In the remainder of Chapter 5, Aristotle elaborates upon these criteria with two important

considerations. Concerning the first criterion, Aristotle explains that whatever comes to be διὰ

τύχην and διὰ τὸ αὐτόματον, comes to be ‘neither by necessity and always, nor for the most part’

because it comes to be by virtue of accident (κατὰ συμβεβηκὸς γένηται),89

and both τὸ αὐτόματον

and τύχη are causes by virtue of accident (αἴτια κατὰ συμβεβηκός).90

This, as we have pointed out

earlier, explains why chance occurrences are considered to be random (ὅπως ἂν τύχῃ),91

indeterminate (ἀόριστον),92

obscure to the human mind (ἄδηλος ἀνθρωπίνῃ διανοίᾳ)93

and not

susceptible of scientific understanding (ἐπιστήμη οὐκ ἔστιν αὐτοῦ).94

More importantly, with this

first clarification, Aristotle is now in a position to provide a general definition of the phenomenon

of chance: whenever a thing such as might come to be for the sake of something comes to be by

86

Cfr. Part II, Chapter 1. 87

Phys. B 5, 196b 12-13; cfr. also 196b 20: “in the things that come to be beside what is necessary and what occurs for

the most part (τοῖς παρὰ τὸ ἀναγκαῖον καὶ τὸ ὡς ἐπὶ τὸ πολύ)”; and 197a 34-35: “in the things that are capable of

coming to be neither simply nor for the most part (ἐν τοῖς ἐνδεχομένοις γίγνεσθαι μὴ ἁπλῶς μηδ’ ὡς ἐπὶ τὸ πολύ). 88

Phys. B 5, 197a 35; cfr. also 196b 21: “to which it belongs to be for the sake of something (περὶ ἃ ἐνδέχεται ὑπάρχειν

τὸ ἕνεκά του).” 89

Phys. B 5, 196b 23 and 197a 12-13. 90

Phys. B 5, 196b 25, 28, and 197a 13 and 32-33. 91

Phys. B 4, 196a 22; B 5, 197a 22; Metaph. E 2, 1027a 17; Metaph. 30, 1025a 25; Metaph. K 8, 1064b 36; cfr. also

De Caelo B 5, 287b 24-25 and B 8, 289b 25-27. 92

Phys. B 5, 196b 28; 197a 8, 9, and 20-21; B 6, 198a 5; Metaph. 30, 1025a 25; Metaph. K 8, 1065a 25, 32-33; cfr.

also An. Pr. A 13, 32b 10; Rhet. I 10, 1396a 32-34. 93

Phys. B 4, 196b 6; cfr. also Phys. B 5, 197a 10. 94

Metaph. E 2, 1026b 26-27; cfr. also Metaph. E 2, 1026b 3-5; 1027a 19-21; Metaph. K 8, 1064b 17-19, 30-32, 1065a

3-6, 33-34; Phys. B 5, 197a 18; An. Post. I 30, 87b 19-21.

108

virtue of accident, then we say that it happens ἀπὸ τύχης.95

Aristotle illustrates this general

definition with a famous example:

As has been said, then, whenever this happens over something which comes to be for something

(ὅταν ἐν τοῖς ἕνεκά του γιγνομένοις τοῦτο γένηται), then it is said to be ἀπὸ ταὐτομάτου or ἀπὸ

τύχης. (The difference between these two we shall have to determine later; for the moment this much

is plain, that both are to be found among things which are for something.) Thus a man would have

come for the purpose of getting back the money when his debtor was collecting contributions, if he

had known; in fact, he did not come for this purpose (ἦλθε δ’ οὐ τούτου ἕνεκα), but it just happened

that he came (ἀλλὰ συνέβη αὐτῷ ἐλθεῖν), and did what was for getting back the money. And that,

though he used to go to the place neither for the most part nor necessarily. The end, the recovery, is

not one of the causes in him, but it is an object of choice and an outcome of thought. And in this case

the man's coming is said to be ἀπὸ τύχης, whereas if he had chosen and come for this purpose, or

used to come always or for the most part, it would not be said to be ἀπὸ τύχης. Clearly, then, τύχη is

an accidental cause (αἰτία κατὰ συμβεβηκὸς) in connection with those among things for something

which are objects of choice.96

For Aristotle, this example offers a paradigmatic instance of something occurring by chance – in the

generic sense, as Aristotle explicitly suspends the judgment about the distinction between τὸ

αὐτόματον and τύχη. The man’s coming to the market and recovering his money is something ‘such

as might come to be for the sake of something’, that is, something that the man could have done as a

result of deliberate action aimed precisely at such an outcome. Yet, as it was not the purpose of his

action, as it came about by accident, the man’s coming to the market and recovering his money is

something that can be said to have occurred by chance.

Concerning the second criterion, Aristotle explains that the things ‘such as might come to be

for the sake of something’ are the sort of things “which might have come to be as the result of

thought or nature (ὅσα τε ἀπὸ διανοίας ἂν πραχθείη καὶ ὅσα ἀπὸ φύσεως)”,97

since both τὸ

αὐτόματον and τύχη are “causes of things for which mind or nature could be responsible (αἴτια ὧν

ἂν ἢ νοῦς γένοιτο αἴτιος ἢ φύσις)”.98

95

Cfr. Phys. B 5, 196b 15-24. 96

Phys. B 5, 196b 29 - 197a 6 (Charlton’s translation, with modifications). 97

Phys. B 5, 196b 22; cfr. also Metaph. K 8, 1065a 26-32: “ὸ δὲ ἕνεκά του ἐν τοῖς φύσει γιγνομένοις ἢ ἀπὸ διανοίας

ἐστίν, τύχη δέ ἐστιν ὅταν τι τούτων γένηται κατὰ συμβεβηκός· ὥσπερ γὰρ καὶ ὄν ἐστι τὸ μὲν καθ’ αὑτὸ τὸ δὲ κατὰ

συμβεβηκός, οὕτω καὶ αἴτιον. ἡ τύχη δ’ αἰτία κατὰ συμβεβηκὸς ἐν τοῖς κατὰ προαίρεσιν τῶν ἕνεκά του γιγνομένοις, διὸ

περὶ ταὐτὰ τύχη καὶ διάνοια.” 98

Phys. B 6, 198a 6.

109

Many scholars think that this second clarification enables Aristotle to draw the distinction

between the generic concept of chance on the one hand and the specific concepts of luck and

spontaneity on the other. Such a distinction is drawn as follows: whenever something that might

come to be ἕνεκά του comes to be by virtue of accident, we speak generically of something coming

to be διὰ τὸ αὐτόματον, that is to say, by chance; however, given that the things that come to be

ἕνεκά του are fundamentally of two sorts, namely, either ‘things that might have come to be as the

result of thought (ὅσα τε ἀπὸ διανοίας ἂν πραχθείη)’ or ‘things that might have come to be as the

result of nature (ὅσα ἀπὸ φύσεως)’, we ought to speak specifically of things coming to be ἀπὸ τύχης

– that is to say, by luck – only when that which comes to be by virtue of accident is something that

might have come to be ἀπὸ διανοίας, while we ought to speak specifically of things coming to be

ἀπὸ ταὐτομάτου – that is to say, spontaneously – whenever that which comes to be by virtue of

accident is something that might have come to be ἀπὸ φύσεως.99

Hence, according to this

distinction, whereas we can speak generically of chance as the cause κατὰ συμβεβηκός of the sort

of things ‘which might come to be for the sake of something (ὅσ’ ἂν γένοιτο ἕνεκά του),’ we ought

to refer more specifically to luck as the cause κατὰ συμβεβηκός of the sort of things ‘which might

have come to be as the result of thought (ὅσα ἀπὸ διανοίας ἂν πραχθείη)’, and to spontaneity as the

cause κατὰ συμβεβηκός of the sort of things ‘which might have come to be as the result of nature

(ὅσα ἀπὸ φύσεως ἂν πραχθείη)’. This distinction seems supported by Aristotle’s claim that διάνοια

and τύχη “concern the same objects (περὶ τὸ αὐτὸ)”,100

and by Aristotle’s observation that only τύχη

can be determined as either good (ἀγαθὴ) or bad (φαύλη) – that is, as either good luck (εὐτυχία) or

bad luck (δυστυχία) 101

– two categories that apply, in the proper sense, only in the sphere of human

action.102

99

Cfr. BALME [1939], p. 131. 100

Phys. B 5, 197a 6-7. 101

Cfr. Phys. B 5, 197a 25-27 and B 6, 197b 1-5. 102

Cfr. Phys. B 6, 197b 1-13: “For luck and what is from luck (ἡ μὲν γὰρ τύχη καὶ τὸ ἀπὸ τύχης) belong only to things

which can be lucky (τὸ εὐτυχῆσαι) and in general engage in rational activity. Hence luck must be concerned with things

achievable by such activity. It is an indication of this that good fortune is thought to be the same as happiness or close to

110

Such, then, is the way in which in Aristotle is thought to define the generic concept of

chance and to articulate the two specific and complementary concepts of luck and spontaneity.

Many commentators have pointed out that the example provided by Aristotle to illustrate and

corroborate his generic definition of chance corresponds to a specific case of luck, since the result

accidentally brought about by the men who went to the market is the sort of thing ‘which might

have come to be as the result of thought (ὅσα ἀπὸ διανοίας ἂν πραχθείη)’. This choice seems to be

only natural, for at least two reasons. To begin with, it is clear that the only way to instantiate a

generic concept is by means of a case corresponding to one of its infimae species, as every concrete

instance necessarily belongs to either one or the other species;103

in addition, the choice of the case

of luck befits Aristotle’s famous epistemological precept that we should always begin an

investigation by looking at what is ‘clearer and more knowable to us’ in order to reach an

understanding of what is ‘clearer and more knowable by nature.’104

As Rossi has pointed out, Aristotle does not explicitly distinguish between the generic

concept of chance and the specific concept of spontaneity. Moreover, as many scholars have

argued, Aristotle appears to offer no example in the Physics of a case corresponding to the specific

concept of spontaneity. However, such a distinction seems to be directly implied by Aristotle’s

division between ‘things that might have come to be ἀπὸ διανοίας’ and ‘things that might have

come to be ἀπὸ φύσεως’. According to Aristotle, in fact, διάνοια (or νοῦς) and φύσις are the two

καθ’ αὑτό causes of genuine teleological processes; and, the proper καθ’ αὑτό causes due to διάνοια

or φύσις explains why things due to thought or nature come to be ‘either always or for the most part

in the same way’. Conversely, then, we should think of τύχη and τὸ αὐτόματον (in the specific

it (ταὐτὸν εἶναι τῇ εὐδαιμονίᾳ ἡ εὐτυχία ἢ ἐγγύς), and happiness is a kind of rational activity: it is activity going well (ἡ

δ’ εὐδαιμονία πρᾶξίς τις· εὐπραξία γάρ). So what is incapable of such activity, can do nothing as the outcome of luck.

Hence nothing done by an inanimate object, beast, or child, is the outcome of luck, since such things are not capable of

choosing. Nor do good or bad fortune belong to them (οὐδ’ εὐτυχία οὐδ’ ἀτυχία ὑπάρχει τούτοις), unless by a

resemblance (εἰ μὴ καθ’ ὁμοιότητα), as Protarchus said that lucky are the stones from which altars are made, since they

are honored, whereas their fellows are trodden underfoot. In a way these things can undergo something as the outcome

of luck, when a person engaged in activity concerning them achieves something as an outcome of luck; but otherwise

not”. 103

ROSSI [2011], p. 168. 104

Cfr. Phys. B 1, 184a 16-18.

111

sense) as the two corresponding κατὰ συμβεβηκός causes of what could come to be, respectively,

due to thought and nature. Hence, according to this interpretation, we should think of luck and

spontaneity as the two corresponding accidental causes of what normally comes to be, respectively,

by virtue of διάνοια (or νοῦς) and φύσις.

This analysis allows us to uncover the assumptions that have led scholars to arrive at the

standard interpretation of the Metaphysics. Many in fact are of the opinion that the discussion of τὸ

αὐτόματον in Metaphysics Z 7-9 builds upon the analysis of τὸ αὐτόματον in Physics B 4-6, and

develops themes implicitly implied by such an analysis. According to this interpretation, then, the

Metaphysics’ discussion concerning that which comes to be by art (τέχνῃ) is a reiteration and

development of the Physics’ analysis of that which might comes to be from thought (ἀπὸ διανοίας).

So the Metaphysics’ example of health being restored not only by medicine but also ἀπὸ

ταὐτομάτου would have to be understood in terms of the Physics’ distinction between causes καθ’

αὑτό and causes κατὰ συμβεβηκός. The κατὰ συμβεβηκός recovery of health would thus be

interpreted as an instance of recovery of health by chance, and more particularly, by luck (ἀπὸ

τύχης), as health is the sort of thing ‘which might have come to be as the result of thought (ὅσα ἀπὸ

διανοίας ἂν πραχθείη)’.

The two contrasting examples of artificial production presented in Metaphysics Z, namely of

a house and health, appear to illustrate the Physics B analysis of τύχη and τὸ αὐτόματον. The art of

building and the art of medicine are, in fact, the καθ’ αὑτὸ causes, respectively, of a house and

health. Note, however, that while Aristotle believes that a house is always produced by

housebuilders and that it cannot be produced in any other way, this is not true for everything which

is produced καθ’ αὑτὸ, for although medicine is the καθ’ αὑτὸ cause of health, it is not the case that

health is always produced by medicine, as it can also be produced ἀπὸ ταὐτομάτου. This distinction

seems to conform to Aristotle’s claim that what comes to be through a καθ’ αὑτὸ cause, comes to be

‘either always or for the most part in the same way’. Scholars who adopt the standard interpretation

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of the Metaphysics believe that Aristotle’s point is that health is an instance of something produced

by a cause καθ’ αὑτὸ only for the most part, with the implication that sometimes – that is, κατὰ

συμβεβηκός and therefore neither always nor for the most part – health can come about without the

action of a doctor.

Note that what makes it possible to interpret the Metaphysics’ example of the recovery of

health ἀπὸ ταὐτομάτου as the unusual or exceptional production, without a doctor, of something

which is normally produced by medicine, is the assumption that in the case of the recovery of health

without medicine – that is, in the absence of synonymous causation – the recovery of health occurs

by accident. As we have in fact seen in the Physics, Aristotle explains that what comes to be either

διὰ τύχην or διὰ τὸ αὐτόματον comes to be ‘neither always nor for the most part’ because τύχη and

τὸ αὐτόματον are accidental causes. Hence, the critical assumption on which the standard

interpretation of the Metaphysics rests is the belief that the Metaphysics’ account of τὸ αὐτόματον

as the privation (στέρησις) of artificial synonymous causation corresponds to the Physics’ analysis

of τύχη as the accidental (κατὰ συμβεβηκός) cause of that which may come to be ἀπὸ διανοίας.

Just, then, as the Metaphysics’ discussion of what comes to be by art (τέχνῃ) is taken to

exemplify the Physics’ analysis of what comes to be from thought (ἀπὸ διανοίας), so, too, the

standard interpretation takes the Metaphysics’ discussion of what comes to be by nature (φύσει) as

an endorsement and development of the Physics’ analysis of what might come to be from nature

(ἀπὸ φύσεως). In fact, some believe that this correspondence between the two texts is even more

relevant, for they presume that it provides an analysis of the alleged specific sense of τὸ αὐτόματον,

which is only implied in the Physics. Those who favor this interpretation take the Metaphysics’

account of spontaneous generation to exemplify precisely the alleged specific sense of τὸ

αὐτόματον. In so doing, spontaneity is taken to be the counterpart in nature of what luck is for

products of art, on the assumption that both spontaneity and luck are two complementary species of

the general concept of chance. According to this assumption, then, the aim of Metaphysics Z 7-9 is

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to illustrate the parallel between the chance recovery of health and the chance generation of living

beings, and hence, to show that what comes to be spontaneously in the field of nature has the same

structure and follows the same principles as what comes to be by luck in the field of human

activities.105

If, therefore, we assume that spontaneity is taken to be the counterpart in nature of what luck

is for products of art, then it seems only natural to expect to find in nature not only creatures that are

always born from other creatures of the same nature, like men, but also creatures that are born from

other creatures of the same nature only for the most part, but which can sometimes – by accident

and therefore neither always nor for the most part – also be generated without a parent of the same

nature. Hence, according to this interpretation, the account of spontaneity of Metaphysics Z 7-9

would imply that just as in some cases of artificial productions the same results that for the most

part are produced by the exercise of an art can also, by accident and hence exceptionally, be

produced by luck, so too in some cases of natural generations the same animals that are normally

generated from seed can also, by accident and hence exceptionally, be generated without seed.

Even in this case, then, the critical assumption on which the standard interpretation rests is

the belief that the Metaphysics’ account of spontaneity as the privation (στέρησις) of natural

synonymous causation corresponds to the Physics’ analysis of the alleged specific sense of τὸ

αὐτόματον as the accidental (κατὰ συμβεβηκός) cause of what may come to be ἀπὸ φύσεως. In

general terms, therefore, the standard interpretation rests on the assumption that the Metaphysics’

account of causation ἐκ συνωνύμου – the sort of causation responsible for things that come to be

either φύσει or τέχνῃ – is equivalent to the Physics’ account of causation καθ’ αὑτό – the sort of

causation responsible for things that come to be either ἀπὸ φύσεως or ἀπὸ διανοίας. Conversely,

and more importantly, the standard interpretation rests on the crucial assumption that the

Metaphysics’ account of τὸ αὐτόματον as the στέρησις of synonymous causation is equivalent to the

105

Cfr. BALME [1939], p. 129 and 132.

114

Physics’ analysis of chance as the cause κατὰ συμβεβηκός of what might have come to be as a

result of thought or nature. Thus, the idea of a genus-species homonymy of τὸ αὐτόματον, the

identification of causation ἐκ συνωνύμου with καθ’ αὑτό causation, and the corresponding

identification of the στέρησις of synonymous causation with κατὰ συμβεβηκός causation, are the

crucial assumptions that have led commentators to believe that the Physics implies, and the

Metaphysics endorses, a theory of random spontaneous generation.

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5. Chance in Physics B 4-6: An Alternative Interpretation

The view that the Metaphysics endorses a theory of random spontaneous generation inconsistent

with the regular spontaneous generation of living beings rests on the assumption of a

correspondence between the account of spontaneity in the Metaphysics and a particular

interpretation of the analysis of τὸ αὐτόματον in the Physics. This view, as we have seen,

presupposes that Physics B 4-6 and Metaphysics Z 7-9 provide a univocal ‘theoretical’ account of

spontaneity that contradicts the more ‘empirical’ account of the biological works. A closer and

independent analysis of the Metaphysics’ references to spontaneous generation, however, reveals

that Metaphysics Z 7-9 actually provides an almost verbatim account of the views expressed in the

Historia Animalium and De Generatione Animalium, which suggests that the alleged inconsistency

often attributed to Aristotle is actually derived from an incorrect set of assumptions regarding the

correlation between the Physics’ analysis of τὸ αὐτόματον and the account of spontaneity in the

Metaphysics.

In order to test the errors in such assumptions, it is necessary to start by examining the

Physics’ and the Metaphysics’ accounts of τὸ αὐτόματον on their own terms, with a view to

highlight their differences and peculiarities. Such an independent analysis of both texts reveals that

the Physics’ and the Metaphysics’ treatment of τὸ αὐτόματον bear only superficial similarities, and

that these works do not in fact offer any unitary ‘theoretical’ account of spontaneity.

There are at least five major differences that challenge the assumption of an overall

correspondence between the analysis of τὸ αὐτόματον in Physics B 4-6 and the account of

spontaneity in Metaphysics Z 7-9.

The first difference concerns the role of φύσις in the account of τὸ αὐτόματον. As we have

seen, one of the presuppositions behind the standard interpretation is the belief that the

Metaphysics’ account of what comes to be by nature (φύσει) corresponds to the Physics’ analysis of

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what might come to be from nature (ἀπὸ φύσεως). Against this presupposition, however, we should

note that while in Metaphysics Z φύσις is presented as an inner principle of coming into being (τοῦ

γίγνεσθαι), in Physics B Aristotle defines φύσις as an inner principle of motion and rest (τοῦ

κινεῖσθαι καὶ ἠρεμεῖν) according to the three accidental modalities of place, quantity, and quality

(τὰ μὲν κατὰ τόπον, τὰ δὲ κατ’ αὔξησιν καὶ φθίσιν, τὰ δὲ κατ’ ἀλλοίωσιν).106

The second difference concerns the role of τέχνη and διάνοια in the account of τύχη.

According to the standard interpretation, the Metaphysics’ discussion concerning what comes to be

by art (τέχνῃ) is taken to exemplify the Physics’ analysis of what comes to be from thought (ἀπὸ

διανοίας). Against this assumption, however, we should point out that while in Metaphysics Z the

discussion of what comes to be τέχνῃ allows Aristotle to provide an account of τὸ αὐτόματον on a

model based on artificial productions (ποιήσεις), in Physics B, the discussion of what comes to be

ἀπὸ διανοίας allows Aristotle to provide an analysis of τύχη on a model based on practical actions

(πράξεις).

The third difference concerns the distinct argumentative strategies adopted in the two texts.

This difference is closely connected with the distinction between the practical model of the Physics

and the technical model of the Metaphysics, for while the analysis of luck in the domain of human

actions is used by Aristotle as the basis for a generalization leading to an account of chance in the

domain of natural motions, the analysis of τὸ αὐτόματον in the domain of human productions, by

contrast, serves as the basis for an analogy leading to an account of spontaneity in the domain of

natural generations. This runs against the assumption held by supporters of the standard

interpretation that luck and spontaneity fall within the general definition of chance.

106

Cfr. Phys. B 1, 192b 13-15 and 20-24; cfr. also Metaph. 4, 1014b 18-20 and 1015a 17-19. Note that while in

Physics both κίνησις and μεταβολή are used as names for change in general, according to all four modalities –

substance, quantity, quality, and place – in Physics Aristotle points out that the identification of κίνησις and μεταβολή

is only provisional; in fact, starting in Physics E, Aristotle argues on ontological grounds that only the term μεταβολή

ought to be used in the generic sense, while κίνησις ought to be restricted to include only growth and diminution,

alteration, and locomotion, but not γένεσις.

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The fourth difference concerns the main intentions behind the analysis of τὸ αὐτόματον in

the two texts. This difference has been generally overlooked by Aristotelian scholars, who have

failed to notice that while the Physics – with its practical model and generalizing argument – is

mainly engaged in a polemical discussion, targeting cosmogonies and zoogonies developed in the

context of natural philosophy, the Metaphysics – with its productive model and analogizing

argument – offers instead a constructive discussion, resting on hypotheses developed in the context

of medical science. This goes against the assumption, held by supporters of the standard

interpretation, that Aristotle endorses the view concerning the generation ἀπὸ τοῦ αὐτομάτου of

living beings that seems to be implied in the analysis of the Physics.

Finally, and most importantly, the fifth difference between the Physics and the Metaphysics

concerns the very definition of τὸ αὐτόματον, for while in Physics B 4-6 τὸ αὐτόματον is presented

as an accidental cause (αἴτιον κατὰ συμβεβηκός) of the sort of things that might come to be ἀπὸ

διανοίας and ἀπὸ φύσεως, in the Metaphysics τὸ αὐτόματον is instead presented as a privation

(στέρησις) of τέχνη and φύσις. This stands against the belief that Physics B 4-6 and Metaphysics Z

7-9 offer a univocal ‘theoretical’ account of spontaneity, and suggests instead that the term ‘τὸ

αὐτόματον’ is used in the two works with an equivocal meaning, which cannot be equated to its

alleged genus-species homonymy. The standard interpretation, as we have seen, holds that the

Metaphysics’ account of causation ἐκ συνωνύμου is equivalent to the Physics’ account of causation

καθ’ αὑτό, and conversely, that the Metaphysics’ account of τὸ αὐτόματον as the στέρησις of

synonymous causation is equivalent to the Physics’ analysis of chance as the cause κατὰ

συμβεβηκός of what might have come to be as a result of thought or nature. This assumption is

essential to the standard interpretation, as the alleged accidental character of spontaneity is used to

justify the claim that in the Metaphysics Aristotle endorses the belief in the ‘irregular and unusual

generation, without seed, of animals that are standardly generated from seed’.107

But, as we shall

107

BOSTOCK [1994], pp. 138-139.

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see, in the Metaphysics Aristotle expressly denies that τὸ αὐτόματον is an accidental cause, which

explains why he never claims that spontaneity is an irregular or unusual phenomenon in

Metaphysics Z 7-9.

Before we can appreciate the significance of these differences, however, it is necessary to

examine the legitimacy of the claim that the Physics implicitly distinguishes a specific sense of τὸ

αὐτόματον, which is explicitly analyzed only in the Metaphysics. As we have seen, many scholars

have insisted that Aristotle relies on the distinction between ‘what might have come to be as a result

of nature’ and ‘what might have come to be as a result of thought’ with a view to discerning, within

the scope of the generic sense of τὸ αὐτόματον (used to indicate the general phenomenon of

chance), between the specific sense of τὸ αὐτόματον (used to express the specific phenomenon of

spontaneity), and the proper sense of τύχη (used to express the specific phenomenon of luck).108

In

the alleged specific sense, τὸ αὐτόματον is thought to be the counterpart in nature of what τύχη is in

the domain of human affairs. According to this distinction, while τύχη is the accidental cause of

what, for the most part, comes to be as a result of thought, in its specific sense, τὸ αὐτόματον is the

accidental cause of what, for the most part, comes to be as a result of nature – hence the idea that

the application of this sense of τὸ αὐτόματον to the generation of living beings entails the idea of

random spontaneous generation.

And yet, no element in the Physics supports such systematization of these terms. As

Charlton, among others, has pointed out, “if that which is lucky is something which – or the

opposite of which – might have been due to thought, we might expect the automatic to be

something which (or the opposite of which) might have been due to nature. Aristotle's examples

hardly answer this expectation”.109

108

Cfr. Part II, Chapter 4. 109

CHARLTON [1970], p. 109; cfr. also ROSS [1936], p. 40; LENNOX [1982], p. 234; QUARANTOTTO [2005], p.

77, ROSSI [2011], pp. 258-263; and JOHNSON [2012], p. 144.

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Indeed, the problem pointed out by Charlton and others is not so much due to Aristotle’s

examples, but more precisely due to the expectation of finding in the Physics a specific as well as a

generic sense of τὸ αὐτόματον. In fact, when Aristotle seeks to establish the difference between

τύχη and τὸ αὐτόματον, he does not rely on the distinction between ‘what might have happened as a

result of nature’ and ‘what might have happened as a result of choice’. The only difference between

τύχη and τὸ αὐτόματον, according to Aristotle, is that τὸ αὐτόματον applies to more things than

τύχη does, for while things that occur ἀπὸ τύχης happen only to subjects capable of choice, things

that happen ἀπὸ τοῦ αὐτομάτου are said to happen also to subjects which are not capable of choice.

There is no hint, implicit or otherwise, that Aristotle distinguishes τὸ αὐτόματον and τύχη in any

other way:

They differ in that τὸ αὐτόματον applies to more things (ἐπὶ πλεῖόν), for everything which is ἀπὸ

τύχης is also ἀπὸ ταὐτομάτου, but not everything which is the latter is also ἀπὸ τύχης. For τύχη and

what is ἀπὸ τύχης belong only to things which are capable of good fortune and in general of action

(ἐστὶν ὅσοις καὶ τὸ εὐτυχῆσαι ἂν ὑπάρξειεν καὶ ὅλως πρᾶξις). Therefore τύχη must be concerned

with things achievable by such activity. It is an indication of this that good fortune (εὐτυχία) is

thought to be the same, or nearly the same, as happiness, and happiness to be a kind of action, since

it is action going well. Hence what is not capable of action (ὁπόσοις μὴ ἐνδέχεται πρᾶξαι) cannot do

anything ἀπὸ τύχης. Therefore neither an inanimate thing, nor a beast, or a child can do anything ἀπὸ

τύχης, since such things are not capable of choice (ὅτι οὐκ ἔχει προαίρεσιν). Nor do good or ill

fortune belong to them (οὐδ’ εὐτυχία οὐδ’ ἀτυχία ὑπάρχει τούτοις), unless by a similarity (εἰ μὴ καθ’

ὁμοιότητα), as Protarchus said that lucky (εὐτυχεῖς) are the stones from which altars are made, since

they are honored, while their fellows are trodden underfoot. In a way (πως) these things can undergo

something ἀπὸ τύχης, when a person engaged in activity concerning them achieves something ἀπὸ

τύχης, but otherwise not. τὸ αὐτόματον, on the other hand, is found both in animals other than man

and in many inanimate objects. Thus we say that the horse came αὐτόματος in that it was saved

because it came, but it did not come for the sake of being saved. Again, the tripod fell αὐτόματος

because it was set up for someone to sit on, but it did not fall for someone to sit on. […] And the

stone did not fall for the purpose of hitting someone; it fell, then, ἀπὸ τοῦ αὐτομάτου, in that it might

have fallen through someone's agency (ὑπὸ τινὸς) and for the purpose of hitting (τοῦ πατάξαι

ἕνεκα).110

In this passage, which presents Aristotle’s most detailed account of the difference between τύχη and

τὸ αὐτόματον, we find no trace of an alleged ‘specific’ sense of τὸ αὐτόματον, but only a distinction

in scope between τύχη and τὸ αὐτόματον. It is important to note the method used by Aristotle to

differentiate the two concepts, which consists in taking events occurring by luck (ἀπὸ τύχης) – that

110

Phys. B 6, 197a 36 – 197b 32.

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is, events relating only to agents capable of πρᾶξις and προαίρεσις – as starting points and referents

for an analysis that he then generalizes to events that are due to chance (ἀπὸ τοῦ αὐτομάτου) – that

is, events relating also to other kinds of ‘agents’, which are incapable of doing anything ἀπὸ τύχης

insofar as they are neither capable of action (ὁπόσοις μὴ ἐνδέχεται πρᾶξαι) nor capable of choice

(οὐκ ἔχει προαίρεσιν).

A crucial aspect of Aristotle’s strategy is that by generalizing the analysis of luck to the

analysis of chance, he is at once establishing that the very same structure of events occurring ἀπὸ

τύχης also defines events occurring ἀπὸ τοῦ αὐτομάτου, with the only difference being that the

latter affect not only human beings, insofar as they are agents capable of choice, but all other living

beings and inanimate objects as well. Aristotle further recognizes that ‘by virtue of similarity (καθ’

ὁμοιότητα)’, things that occur by chance to non-rational agents can ‘in a way (πως)’ be seen as

bestowing good or bad fortune to them. Note, too, that unlike the Metaphysics, in which Aristotle

restricts events that occur ἀπὸ τοῦ αὐτομάτου to some living beings, in the Physics, he generalizes

its occurrences to all living and non-living beings alike.

All of the examples provided in this passage confirm that the only distinction between τύχη

and τὸ αὐτόματον drawn by Aristotle is a distinction in scope. This is perhaps most clearly

illustrated in the final example, which involves the falling of an inanimate object, a stone, hitting

someone ἀπὸ τοῦ αὐτομάτου. Aristotle explains that the reason why we say that the stone has fallen

ἀπὸ τοῦ αὐτομάτου is that, while it did not fall to hit someone, it might have fallen by the action of

someone (ὑπὸ τινός) with the intention of hitting someone else. Clearly, then, the reason why such

an event is classified by Aristotle as happening ἀπὸ τοῦ αὐτομάτου, and not ἀπὸ τύχης, is not that

the accidental result of the falling of the stone is something ‘of which nature might be the cause,’

since hitting someone is manifestly recognized as something of the sort that might have been

brought about by virtue of a deliberate action. This example, therefore, does not fit the so-called

‘specific’ sense of τὸ αὐτόματον, and hence it is misleading to translate the passage, as most authors

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do, as saying that the stone fell and hit someone ‘spontaneously’. Rather, this case fits Aristotle’s

general account of τὸ αὐτόματον, and hence it is more appropriate to say that the stone fell and hit

someone ‘by chance’, for despite the fact that the result is something ‘of which reason might be the

cause’, it is nonetheless not brought about by a rational agent, but by an inanimate object, moving

according to its own nature.

The second example, which considers the falling of an artificial inanimate object, further

stresses Aristotle’s point: a tripod falls on its feet αὐτόματος because, though it fell in a way such as

to serve as a seat, it did not fall in order to serve as a seat. Clearly, here too the accidental result of

the falling of the tripod is something of the sort that might have been brought about by virtue of a

deliberate action, not by nature, yet Aristotle uses the category of τὸ αὐτόματον to classify an event

of this sort. There is no need to read this case as an instance of ‘spontaneity’ in the specific sense, as

many authors do, for clearly, according to Aristotle’s distinction, the only defining element that

makes it a case of an event occurring ἀπὸ τοῦ αὐτομάτου, and not ἀπὸ τύχης, is that the accidental

result is brought about by an object whose motions do not originate from reason and choice, and

hence, cannot be classified as an instance of the narrower phenomenon of luck, but rather as an

instance of the broader phenomenon of chance.

The difficulty of fitting these cases within the alleged articulation of chance in luck and

spontaneity has led some authors to classify such examples as instances of ‘mixed spontaneity’, that

is, cases in which natural processes overlap with practical results.111

However, the addition of this

extra class of phenomena is clearly unnecessary, and shows the inadequacy of the alleged existence

of a genus-species homonymy of τὸ αὐτόματον.

The first example, involving the motion of a non-rational animal, presents a very interesting

case. Simplicius, and many modern commentators after him, provide a framework to interpret this

example so that it conforms to the structure apparent in the other two cases. According to this

111

Cfr. for example ROSSI [2011], p. 262.

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interpretative framework, the horse was captured by the enemy, but being thirsty, it returned to its

stable in search of water; there, it was rescued by its owner and hence was saved (ἐσώθη).112

Just as

in the other two examples, in this case, too – if indeed this interpretation is correct – the result of

which τὸ αὐτόματον is said to be the cause is not something that might have been brought about by

nature, but rather of something that might have been brought about by action and choice – in this

case by the action and choice of the owner of the horse – despite the fact that it happened to a

subject incapable of action and choice.

However, there is another equally plausible interpretation of this example that corresponds

with Aristotle’s general account of chance. According to this different interpretation, the result of

the action could indeed be something brought about ἀπὸ φύσεως in the strict Aristotelian sense

described in the Physics, namely by an internal impulse for motion, which belongs to the animal by

virtue of itself.113

In De Anima, for instance, Aristotle claims that the first principle of the soul “is a

power (δύναμις) to preserve in existence (σώζειν) that which possesses it as such”;114

and, in De

Partibus Animalium, he claims that nature (ἡ φύσις) has endowed horses with speed for their safety

(πρὸς σωτηρίαν).115

When a horse perceives a threat or danger, it moves away from it in order to be

safe. So, we can say that the horse could have come for the sake of being saved, yet it came for

another cause, such as thirst or hunger, for example.

Read in this context, the example of the horse that came αὐτόματος might well appear to be

the only genuine case of the alleged specific sense of τὸ αὐτόματον. Yet, Aristotle does not intend

to contrast the example of the horse with that of the falling tripod as instances of two different

senses of τὸ αὐτόματον. In terms of differentiating τύχη from τὸ αὐτόματον, it is irrelevant whether

112

Simplicius, In Phys. 347. 4-8: “ὁ γὰρ ἵππος ὁ ληφθεὶς ὑπὸ τῶν πολεμίων εἶτα διψήσας καὶ ἐλθὼν ἐπὶ τοὺς προτέρους

τόπους τοῦ πιεῖν ἕνεκα καὶ ἀναληφθεὶς ὑπὸ τοῦ δεσπότου α ὐ τ ό μ α τ ο ς ἦ λ θ ε , φαμέν, τουτέστιν αὐτόματος ἐσώθη

ἐλθών, ὅτι ἐ σ ώ θ η μὲν ἐ λ θ ώ ν , ο ὐ τ ο ῦ σ ω θ ῆ ν α ι δ ὲ ἕ ν ε κ ε ν ἦ λ θ ε .” Similarly ROSS [1936], p. 522, and

CHARLTON [1970], p. 109, believe that Aristotle is perhaps referring to a horse that loses his rider or groom in a

battle. 113

Cfr. Phys. B 1, 192b 13-14: “ἐν ἑαυτῷ ἀρχὴν ἔχει κινήσεως καὶ στάσεως [...] κατὰ τόπον;” and 192b 18-19: “ὁρμὴν

ἔχει μεταβολῆς ἔμφυτον.” 114

De An. II 4, 416b 17-19. 115

De Part. An. III 2, 663a 1-4.

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the accidental result is something of which nature could have been the cause, or something of which

mind could have been the cause. What does matter in both cases, and the reason why they are both

genuine instances of events occurring by chance, not by luck, is that the accidental result –

something of which either mind or nature could have been the cause – is brought about by a being

that is incapable of deliberation and choice.

The example of the horse, just as all of Aristotle’s other examples, fall into the broader

scope of events due to chance. Indeed, it is the example that best illustrates not only how Aristotle

generalizes the structural elements found in events that occur ἀπὸ τύχης and applies them to events

that occur ἀπὸ τοῦ αὐτομάτου, but also how things that occur ἀπὸ τοῦ αὐτομάτου to non-rational

agents can ‘by virtue of similarity (καθ’ ὁμοιότητα)’ also be said to happen ἀπὸ τύχης. Note that the

very same structure present in events brought about by luck applies, more generally, to any event

brought about by chance: the man could have come to the market in order to recover his money, had

he known that his debtor was there collecting contributions, but instead he came for another reason,

and hence we say that he came and recovered his money ἀπὸ τύχης;116

similarly, the horse could

have come to save itself, had it perceived the danger, but instead it came for another purpose. The

similarity between these two cases makes it easy to see why one may say that the horse too came

and was saved ἀπὸ τύχης and was lucky; yet Aristotle tells us that strictly speaking εὐτυχία and

ἀτυχία can only affect agents capable of choice, and it is therefore more appropriate to say that the

horse came, and was saved ἀπὸ τοῦ αὐτομάτου.

Thus, it is clear that the difference between τύχη and τὸ αὐτόματον is not drawn on the basis

of the distinction between ‘what might be done by nature’ and ‘what might be done by reason’ as

two opposite and complementary species of chance occurrences. Aristotle simply specifies that τύχη

and τὸ αὐτόματον differ in that ‘τὸ αὐτόματον applies to more things’; he therefore includes in the

domain of τὸ αὐτόματον both things of which either nature or reason could be the cause, that is,

116

Cfr. Phys. B 5, 196b 33-36: “οἷον ἕνεκα τοῦ ἀπολαβεῖν τὸ ἀργύριον ἦλθεν ἂν κομιζομένου τὸν ἔρανον, εἰ ᾔδει· ἦλθε

δ’ οὐ τούτου ἕνεκα, ἀλλὰ συνέβη αὐτῷ ἐλθεῖν, καὶ ποιῆσαι τοῦτο τοῦ κομίσασθαι ἕνεκα.”

124

anything which might be done for the sake of something. The only specification that further restricts

the domain of τύχη beyond that of τὸ αὐτόματον is that what occurs ἀπὸ τύχης can only occur to

subjects capable of choice, whereas what occurs ἀπὸ τοῦ αὐτομάτου also occurs to subjects that are

not capable of choice.

Although it is not the case, as some authors have claimed, that in the Physics Aristotle

provides only examples of outcomes that ‘might have come to be as a result of thought (ἀπὸ

διανοίας)’, it is nonetheless clear that all instances of things that come to be ἀπὸ τοῦ αὐτομάτου are

in some way related to things that happen ἀπὸ τύχης. The reason for this, as we have seen, is that the

structure of events occurring ἀπὸ τύχης in the practical domain is taken by Aristotle to be the

referent for an analysis which he generalizes to events occurring ἀπὸ τοῦ αὐτομάτου. The

connection with the practical domain is particularly evident in the last two examples of the passage

of Physics B 6 quoted above, where a stone falls and hits someone by chance ‘because it might have

fallen by the action of someone (ὑπὸ τινός) with the intention of hitting someone else’, or in the

case of a tripod which falls by chance ‘because it was set up for someone to sit on, but it did not fall

for someone to sit on’. Yet the similarity with events occurring ἀπὸ τύχης is also clear from the

example of the ‘lucky’ horse, even if we interpret the accidental outcome as something ‘of which

nature might be the cause’.

Few authors have paid adequate attention to the importance and relevance of the practical

model of chance events assumed in the Physics. And yet, this aspect of Physics B 4-6 is crucial for

at least two reasons.

First, the practical model allows Aristotle to work with the notion of φύσις defined at the

outset of Physics B 1. As previously mentioned, Aristotle does not define φύσις as a principle of

coming into being (τοῦ γίγνεσθαι), as he does in the Metaphysics;117

rather, the Physics mainly

focuses on φύσις as “a principle of motion and rest (κινήσεως καὶ στάσεως), whether in respect of

117

Cfr. Metaph. Z 7, 1032a 12-13 and 15-17.

125

place (κατὰ τόπον), or growth and decay (κατ’ αὔξησιν καὶ φθίσιν), or alteration (κατ’

ἀλλοίωσιν)”,118

that is, with respect to the accidental modes of place, quantity, and quality. Hence,

as accidental causes of ‘what may be due to nature or mind’, τύχη and τὸ αὐτόματον are also

recognized by Aristotle as causes of motion, for when he considers “their ways of being a cause

(τῶν δὲ τρόπων τῆς αἰτίας)” – namely where they belong in his fourfold classification of causality –

he includes them within the causes “from which change originates (ἐν τοῖς ὅθεν ἡ ἀρχὴ τῆς

κινήσεως).”119

All of the examples presented in the Physics fit this description: just as “the man’s

coming is said to be the outcome of luck (καὶ λέγεταί γε τότε ἀπὸ τύχης ἐλθεῖν)”,120

in the same way

“we say that the horse came by chance (ὁ ἵππος αὐτόματος, φαμέν, ἦλθεν)”.121

The same pattern is

present not only in cases that Aristotle himself recognizes as happening ἀπὸ τοῦ αὐτομάτου – for

we say that “the tripod fell down by chance (ὁ τρίπους αὐτόματος κατέπεσεν)”122

and similarly that

“the stone fell down by chance (ἀπὸ τοῦ αὐτομάτου ἄρα κατέπεσεν ὁ λίθος)”123

– but also in cases

cited by other philosophers, which Aristotle does not endorse, as for example in the cosmogonies of

those who make “chance the cause of the entire cosmos,”124

and believe that “what came to be by

chance (ἀπὸ ταὐτομάτου γενέσθαι) is the vortex (τὴν δίνην) and the motion (τὴν κίνησιν) that

separated and arranged the universe in its present order”.125

This leads to the second crucial aspect of the paradigmatic practical model of the Physics.

Although Aristotle does not treat the subject of generation ἀπὸ τοῦ αὐτομάτου of living creatures in

this work, he nevertheless does make mention of such cases. In Physics B 6, in fact, he makes a

brief and passing remark about the role of τὸ αὐτόματον in natural generations, stating that τὸ

αὐτόματον “is furthest separated from what occurs by luck in the things that come to be by nature

118

Cfr. Phys. B 1, 192b 14-15. 119

Phys. B 6, 198a 1-3. 120

Phys. B 5, 197a 3. 121

Phys. B 6, 197b 15. 122

Phys. B 6, 197b 16-17. 123

Phys. B 6, 197b 31. 124

Phys. B 6, 198a 11. 125

Phys. B 4, 196a 26-28.

126

(μάλιστα δ’ ἐστὶ χωριζόμενον τοῦ ἀπὸ τύχης ἐν τοῖς φύσει γιγνομένοις)”.126

The sole purpose of

this passage is to emphasize the distinction between the cases of things being generated τὸ

αὐτόματον and the cases of things being moved ἀπὸ τοῦ αὐτομάτου, as analyzed throughout the

treatise. The parenthetical nature of this remark reveals that Aristotle merely mentions such

occurrences so as to suggest that the sense of τὸ αὐτόματον among ‘the things that come to be by

nature’ goes beyond the focus of the investigation he is undertaking.127

This clarification confirms

at once that all the cases of motion originating ἀπὸ τοῦ αὐτομάτου, though distinct from the cases of

action originating ἀπὸ τύχης, are not, in fact, much distinct from those occurring ἀπὸ τύχης, since

they both share the same structure.

Again, in the same passage, Aristotle claims that things whose generation is ἀπὸ

ταὐτομάτου are those of which we say to a greater extent that they are ἀπὸ ταὐτομάτου and not ἀπὸ

τύχης (τότε οὐκ ἀπὸ τύχης ἀλλὰ μᾶλλον ἀπὸ ταὐτομάτου γεγονέναι φαμέν);128

but, this implies that

things whose motion is ἀπὸ ταὐτομάτου, and which constitute the focus of Physics B 4-6, are those

of which we say to a lesser extent that they are ἀπὸ ταὐτομάτου and not ἀπὸ τύχης. And indeed, as

we have seen, Aristotle claims that ‘by virtue of similarity (καθ’ ὁμοιότητα)’, things that move ἀπὸ

τοῦ αὐτομάτου can ‘in a way’ be said to have a share in τύχη. All the examples of things that

happen ἀπὸ τοῦ αὐτομάτου in the Physics have some connection or bear some similarity with the

domain of πρᾶξις, and therefore they are all related to things that happen ἀπὸ τύχης. But in the case

of the generation of natural beings, according to Aristotle, the connection between τὸ αὐτόματον

and τύχη is severed.

This means that in the Physics itself Aristotle suggests that we cannot apply the very same

analysis of τὸ αὐτόματον elaborated in this particular work to the phenomenon of the generation

ἀπὸ τοῦ αὐτομάτου of living beings. Hence, if anything, the Physics appears rather to entrust to the

126

Phys. B 6, 197b 32-33. 127

This view is held by SIMPLICIUS, In Phys. 352.14 – 353.5. Similarly QUARANTOTTO [2005], p. 75-77 claims

that this case of αὐτόματον does not correspond to the definition of chance offered in Phys. B 4-6. 128

Phys. B 6, 197b 34-35.

127

Metaphysics the task of examining the phenomenon which is said to occur ἀπὸ τοῦ αὐτομάτου, but

which nonetheless falls outside the scope of the analysis of chance of the Physics, namely the

phenomenon of τὸ αὐτόματον as it appears in the generation of living beings.

This thematic shift is made clearer when we consider that instead of the practical model of

the Physics upon which the analysis of τὸ αὐτόματον is based, the Metaphysics relies instead on a

technical model. As we have seen, Aristotle begins his inquiry in Metaphysics Z 7 by claiming that

“of the things that come to be (τῶν δὲ γιγνομένων), some come to be by nature (τὰ μὲν φύσει

γίγνεται), some by art (τὰ δὲ τέχνῃ), and some ἀπὸ ταὐτομάτου”.129

Proponents of the standard

interpretation believe that Aristotle’ analysis of things due to τέχνη in the Metaphysics corresponds

to the analysis of things due to διάνοια in the Physics, and that it is used with the same intent,

namely to provide an account of τύχη.

In fact, however, Aristotle’s different choice is made with the intent to provide an analysis

of a different sort of phenomena. The focus on productions, rather than actions, allows Aristotle to

turn his attention to the generation of living beings ἀπὸ τοῦ αὐτομάτου, rather than to the motion of

natural things ἀπὸ τοῦ αὐτομάτου. In addition, and more importantly, it would appear that the shift

from a practical model to a productive one also leads to a shift in the mode of analysis of τὸ

αὐτόματον.

In the Physics, in fact, Aristotle takes events happening ἀπὸ τύχης in the practical domain as

the starting points and referents for his study, and then generalizes the structure of such occurrences

to the domain of events that happen to beings which are neither capable of action nor choice. Thus,

it is appropriate to say, in accordance with the Physics’s argument, that just as a creditor may meet

his debtor either by luck or intentionally, so too a horse may reach its safety either by chance or by

natural impulse.

129

Metaph. Z 7, 1032a 12-13.

128

In the Metaphysics, on the other hand, the starting points for Aristotle’s study are events

happening ἀπὸ τοῦ αὐτομάτου in the productive domain, not events happening ἀπὸ τύχης in the

practical one; and these are taken as referents for an analogy with the generation ἀπὸ τοῦ

αὐτομάτου of living creatures, not as the basis for a generalization. This is a crucial point: the

‘same things’ that may be brought about both by human artistry and ἀπὸ τοῦ αὐτομάτου are all

particular occurrences of the same sort of phenomenon – they are one and the same τῷ εἴδει. Thus,

the form of health may be brought about in different and particular instances either by medicine or

ἀπὸ τοῦ αὐτομάτου. Certainly, if Aristotle meant to generalize the schema revealed in artificial

productions to the domain of natural generations in the same way in which he generalizes the

schema revealed in practical actions to the domain of natural motions, then it could be correct to say

that he is committed to the belief in random spontaneous generation. If that were in fact the case,

then to say that Socrates may come to be healthy either by medicine or ἀπὸ τοῦ αὐτομάτου just as a

mullet may come to be either from seed or without seed would entail the idea that a particular

specimen of the same species of animals may come to be in either of these two ways.

Yet, as we have seen, this is not how Aristotle’s analysis proceeds, and we should remain

aware of the fact that Aristotle wants to establish only an analogy between the production ἀπὸ τοῦ

αὐτομάτου of health and the generation ἀπὸ τοῦ αὐτομάτου of living beings, thereby conceiving

such relationship in the same way as Aristotle generally conceives the relationship between art and

nature.130

130

An analogy, according to Aristotle, is a correspondence that expresses an identity of relations among four different

terms, so that “the second is related to the first as the fourth is to the third” (Poet. 21, 1457b 16-18). In addition,

Aristotle believes that the sort of unity obtained by means of an analogy is the widest form of unity. Aristotle expresses

this idea by saying that just as “things that are one in species (εἴδει) are all one in genus (γένει), while things that are

one in genus are not all one in species”, so “things that are one in genus are all one by analogy (ἀναλογίᾳ), while things

that are one by analogy are not all one in genus” (Metaph. 6, 1017a 1-3). This last element is important, because

Aristotle believes that the things that are one in γένος are those “to which the same figure of predication applies (ὧν τὸ

αὐτὸ σχῆμα τῆς κατηγορίας)” (Metaph. 6, 1016b 33-34), which entails that the only form of unity among things

which are not included under the same figure of predication is the unity of analogy. But this, then, is the only sort of

unity to be found between things that are produced by art and things that are generated by nature. The terms being

related in the two different spheres, the artificial and the natural, belong in fact to different categories of reality. The

crucial difference between the two cases is that natural beings (τά φύσει ὄντα) are substances, whereas products of art

(τά ἀπὸ τέχνης) are not (this point is stressed with particular emphasis in KATAYAMA [1999] and [2008]). This

129

The use of different models and different argumentative strategies has important

consequences, for just as it shows that the spontaneous generation of living beings cannot be

subsumed under the analysis of events occurring by chance, so, too, it suggests that the production

ἀπὸ τοῦ αὐτομάτου of health cannot be subsumed under the analysis of events occurring by luck, as

is assumed by the standard interpretation.

Such a suggestion is further strengthened by the apparent inconsistency in Aristotle’s use of

terminology. According to the alleged distinction between luck and spontaneity as two species of

chance, the recovery of a man’s health without the actions of a doctor would have to be regarded as

a paradigmatic case of something that could occur ἀπὸ τύχης, given that it is the sort of thing ‘of

which reason could be the cause’ – the art of medicine – and which could affect agents capable of

choice. However, in both the Metaphysics and the biological treatises, Aristotle insists that health is

the sort of thing that can come to be not only from medicine but also ἀπὸ τοῦ αὐτομάτου. The most

immediate explanation for this might be that Aristotle often resorts to the generic concept of chance

instead of the specific concept of luck in an effort to simplify his point. And yet, we should also be

open to the possibility that in these contexts, Aristotle is using the term τὸ αὐτόματον in a different

sense, which cannot be reduced to the analysis of chance.

This alternative is suggested by the passage of Metaphysics Z 7 in which Aristotle claims

that some of the things that come to be by art can come to be “καὶ ἀπὸ ταὐτομάτου καὶ ἀπὸ τύχης” –

both ἀπὸ ταὐτομάτου and ἀπὸ τύχης.131

Again, the most immediate explanation for this might be

that Aristotle is using this expression, somewhat redundantly, in an effort to illustrate the same sort

distinction is epitomized in the particular cases that Aristotle chooses to compare: the substantiality of natural beings, in

fact, is paradigmatically instantiated in living beings that reproduce their own kind, whereas the insubstantiality of

artistic productions is paradigmatically instantiated in a ἕξις like health. It is therefore in the gap that separates the two

distinct kinds of beings, namely the artificial and the natural, that we can measure the distance of what occurs ἀπὸ τοῦ

αὐτομάτου in each case. Hence, whereas in the artistic domain the ‘same’ things being produced both ἀπὸ τέχνης and

ἀπὸ τοῦ αὐτομάτου are the same with respect to a form (ταὐτά τῷ εἴδει), in the natural domain the ‘same’ things

generated both ἀπὸ φύσεως and ἀπὸ τοῦ αὐτομάτου are the same with respect to a genus (ταὐτά τῷ γένει). It is

important to emphasize that this analogical correspondence has a clear ontological basis: according to Aristotle, the only

‘things’ for which art is responsible are particular instances of a certain sort of work, not their εἴδη (Cfr. Metaph. A 1,

981a 16-20). But in the natural domain, and in particular, in the living world, the things for which nature is responsible

are substances, and Aristotle recognizes as substances also the εἴδη of living beings. 131

Metaph. Z 7, 1032a 28-29.

130

of phenomenon. It is more plausible to imagine, however, that Aristotle uses the term τὸ αὐτόματον

in these contexts in the sense ‘furthest separated from what occurs ἀπὸ τύχης,’ which applies

primarily to the spontaneous generation of living beings and, by analogy, to the spontaneous

production of health. But this means that the spontaneous recovery of health is something different

and not entirely reducible to the recovery of health by chance or luck. In particular, this appears to

suggest that the recovery of health by virtue of an accidental cause cannot be identified with the

recovery of health without the action of a doctor, that is, in the absence of synonymous causation.

However, this calls into question the pivotal assumption behind the standard interpretation, namely

the idea that the Metaphysics’ account of spontaneity as the στέρησις of synonymous causation is

equivalent to the Physics’ analysis of chance as the cause κατὰ συμβεβηκός of what might have

come to be as a result of thought or nature.

131

6. Spontaneity is Not an Accidental Cause

In the previous Chapter, we called into question the deeply entrenched belief that in Metaphysics Z

7-9 Aristotle endorses, elaborates upon, and applies his alleged ‘theoretical’ account of spontaneity

presented in Physics B 4-6 to the generation ἀπὸ τοῦ αὐτομάτου of living beings. In addition to

showing that such a belief rests on the mistaken view that there is a genus-species homonymy of τὸ

αὐτόματον, we also exposed three major differences between the two texts, which further confirms

our position.

To begin with, while in the Physics both φύσις and τὸ αὐτομάτον are considered as causes of

change with respect to the accidental modes of place, quantity, and quality, in the Metaphysics they

are instead considered as causes of generation, which suggests that the Metaphysics’ account of

what comes to be by nature (φύσει) is meant to stress elements that cannot be included in the

Physics’ account of what might occur from nature (ἀπὸ φύσεως).

In addition, whereas in the Physics Aristotle compares the causality of φύσις with the

operations of διάνοια or νοῦς, in the Metaphysics he compares it instead with the operations of

τέχνη. Although one might argue that what comes to be by art is but a specification of what comes

to be from reason, it is nonetheless clear that Aristotle’s choice reflects a crucial difference in the

account of τὸ αὐτόματον, for while the Physics’ account is grounded on the analysis of τὸ

αὐτόματον in the practical domain, the Metaphysics’ account is instead grounded on the analysis of

τὸ αὐτόματον in the productive domain, which suggests that the Metaphysics’ account of what

comes to be by art (τέχνῃ) is meant to highlight factors that cannot be subsumed under the Physics’

account of what might happen from reason (ἀπὸ διανοίας).

This leads us to gaining insight into a third major difference between the Physics’ and the

Metaphysics’ account of τὸ αὐτόματον, namely, that the two different models on which the analyses

are based provide starting points for different types of argumentative strategies. As we have seen,

132

whereas in the Physics the causal structure of actions occurring ἀπὸ τοῦ αὐτομάτου to agents

capable of πρᾶξις and προαίρεσις is generalized to changes occurring ἀπὸ τοῦ αὐτομάτου to things

incapable of action and choice, in the Metaphysics, by contrast, the causal structure of processes

occurring ἀπὸ τοῦ αὐτομάτου in the productive sphere is used as the basis for an analogy with the

generation ἀπὸ τοῦ αὐτομάτου of living creatures.

Thus, while the account presented in Physics B 4-6 is based on an analysis of τύχη in human

actions, which is used by Aristotle as the starting point for a generalization that aims to reveal the

causal structure of τὸ αὐτόματον in the analysis of natural motions, the account presented in

Metaphysics Z 7-9 is based on an account of τὸ αὐτόματον in technical productions, which is used

by Aristotle as the starting point of an analogy that aims to provide a causal analysis of spontaneity

in the domain of natural generations. These crucial differences suggest that the account of

spontaneity in Metaphysics Z 7-9 cannot be subsumed under the analysis of τὸ αὐτόματον in

Physics B 4-6, and therefore, that the assumptions behind the standard interpretation of the

Metaphysics are groundless.

There is, however, a fourth and more important distinction to be considered, namely, the fact

that whereas in the Physics τὸ αὐτόματον is presented as a cause κατὰ συμβεβηκός of the sort of

things that might come to be ἀπὸ διανοίας and ἀπὸ φύσεως, in the Metaphysics it is instead

presented as the στερήσεις of τέχνη and φύσις. As we have seen, the fundamental assumption

behind the standard interpretation of the Metaphysics is that the absence of synonymous causation,

which defines spontaneity in Metaphysics Z 7-9, corresponds to the accidental causation, which

defines τὸ αὐτόματον in Physics B 4-6. In order to challenge this assumption, we need to

understand the precise role that accidental causality plays in Aristotle’s account of chance. He

offers a general elucidation of the concept of accidental causality in Physics B 5:

Just as a thing is something either καθ’ αὑτὸ or κατὰ συμβεβηκός, so may it be a cause. For instance,

the art of house-building is a cause καθ’ αὑτὸ of a house, whereas the pale or the musical are causes

κατὰ συμβεβηκός. That which is a cause καθ’ αὑτὸ is determinate (ὡρισμένον), but the cause κατὰ

133

συμβεβηκός is indeterminate (ἀόριστον), for an unlimited number of things coincide in one object

(ἄπειρα γὰρ ἂν τῷ ἑνὶ συμβαίη).132

The transition from the generic concept of accidental cause to its specific role in the account of

chance is carried out in the following passage of Physics B 5, in which Aristotle – in his typical

dialectical fashion – appeals to the notion of accidental causality to prove that chance is the cause of

things that come to be ‘neither always nor for the most part’, and to show that his own theory of

chance preserves some elements of truth underlying the belief of those who think that “nothing

comes to be as an outcome of chance (οὐδὲν γίγνεσθαι ἀπὸ τύχης)”,133

as well as those who think

that chance is a cause “inscrutable to human thought (ἄδηλος ἀνθρωπίνῃ διανοίᾳ)”:134

Necessarily, then, the causes from which what is ἀπὸ τύχης might come to be are indeterminate

(ἀόριστα). That is why τύχη is thought to be an indeterminate sort of thing (τοῦ ἀορίστου εἶναι

δοκεῖ) and inscrutable to men (ἄδηλος ἀνθρώπῳ), and at the same time there is a way in which it

might be thought that nothing comes to be ἀπὸ τύχης. For all these things are rightly said, as might

be expected. There is a way in which things come to be ἀπὸ τύχης, for they come to be κατὰ

συμβεβηκὸς, and τύχη is a cause κατὰ συμβεβηκὸς. But simply, it is the cause of nothing (ὡς δ’

ἁπλῶς οὐδενός). For instance, the cause of a house is a builder, but κατὰ συμβεβηκὸς a flute player.

And the causes of the man’s coming and recovering the money, when he did not come for the sake of

that, are unlimited in number (ἄπειρα τὸ πλῆθος). He might have been hoping to see someone, or

litigating as plaintiff or defendant, or going to the theater. We account for that which is always or for

the most part (ὁ γὰρ λόγος ἢ τῶν ἀεὶ ὄντων ἢ τῶν ὡς ἐπὶ τὸ πολύ), but τύχη appears in the cases

apart from these (ἐν τοῖς γιγνομένοις παρὰ ταῦτα). So since the causes in such cases are

indeterminate, so is τύχη.135

Aristotle’s reasoning can be formalized as a simple syllogism: accidental causes are indeterminate,

and since chance is an accidental cause, chance too is something indeterminate. In order to prove

his point, Aristotle compares two different instances of causality κατὰ συμβεβηκός, one which he

classifies as an instance of τύχη – the paradigmatic case of someone who meets his debtor by luck –

and another which he does not classify as an instance of τύχη – the case of a flute-player being

accidentally a house-builder. According to Aristotle, just as an unlimited number of things may be

counted as accidental causes of a house – a flute player, a pale man, etc. – yet only a house-builder

132

Phys. B 5, 196b 24-29; cfr. Phys. B 3. 133

Phys. B 4, 196a 1. 134

Phys. B 4, 196b 5-7. 135

Phys. B 5, 197a 8-21.

134

can be the cause καθ’ αὑτὸ, so too there are infinite reasons (ἄπειρα τὸ πλῆθος) for going to the

market that may be counted as accidental causes of recovering a debt – hoping to see someone,

litigating as a plaintiff or defendant, or going to the theater – yet it is only when someone goes to

the market in order to recover his debt that one can say that the result is not due to chance.

Note that Aristotle does not mean to say that a particular event due to chance – the same

token of a general type of events, such as this particular occasion of ‘going to the market’– is due to

an unlimited number of accidental causes, for it would be manifestly absurd to say that the man who

went to the market by chance in this particular occasion did so because of an infinite number of

reasons. In any particular instance in which a man goes to the market by chance, there is one precise

accidental intention driving the action, and such accidental intention can be precisely discerned and

is not ‘inscrutable to human thought’. According to Aristotle, it is the same type of events, such the

general type ‘going to the market’, which is due to an unlimited number of accidental causes

whenever it happens to occur ἀπὸ τύχης. What he means to say, therefore, is that the accidental

reasons why a person could go to the market, when he goes to the market by chance, are potentially

unlimited (ἄπειρα) because they are logically indeterminate (ἀόριστα): a man who went to the

market and met his debtor by chance could have gone to the market for any other goal which is not

the recovery of money.

As we have seen, the consideration of chance events in the practical domain, that is to say of

actions due to luck that happen to agents capable of reason and choice, offers Aristotle an analysis

that he then generalizes to movements due to chance that happen to things that are incapable of

reason and choice, as is the case with the horse which came to the stable and was saved by chance.

It is problematic, however, to extend this analysis to the account of τὸ αὐτόματον in the

Metaphysics precisely because the phenomena described as occurring ἀπὸ τοῦ αὐτομάτου in this

work – the recovery of health without the action of a doctor, or the generation of living beings

135

without seed – do not qualify as accidental, or at any rate, do not qualify as accidental in the sense

established in the Physics.

Aristotle himself hints at this problem in a parenthetical passage of Physics B 4-6, whose

anomaly within the context of his investigation on chance has by and large been overlooked by

ancient and modern scholars alike. In the conclusion of his analysis of accidental causes,

immediately after claiming that an unlimited number of things can be the cause by accident of a

chance occurrence, he points out the following difficulty:

However, one may be puzzled about certain cases (ἐπ’ ἐνίων ἀπορήσειεν ἄν τις): could any random

thing (τὰ τυχόντα) come to be a cause of chance (αἴτι’ ἂν γένοιτο τῆς τύχης)? For instance, could the

breath of the wind or the warmth of the sun be the cause of health (οἷον ὑγιείας ἢ πνεῦμα ἢ εἵλησις),

but not having had a hair-cut (ἀλλ’ οὐ τὸ ἀποκεκάρθαι)?136

In this passing remark, Aristotle raises the question as to whether in certain cases (ἐπ’ ἐνίων) it is in

fact correct to think that ‘any random thing (τὰ τυχόντα)’ could be the cause of what comes to be by

chance. This question evidently calls into doubt the point made in the previous section, namely, that

the causes of that which occurs by chance are indeterminate. Aristotle leaves this question

unanswered, and hence, the ἀπορία he raises does not find an apparent solution in this treatise. It is

nevertheless instructive to take note of some of the peculiarities of his choice of example.

There are two reasons why this passage is atypical in the context of Physics B 4-6. To begin

with, Aristotle departs from the practical model of chance that frames his whole treatise, and

instead considers the problem that arises when we try to apply the schema of accidental causation to

the productive domain. This is, in fact, the only passage in the Physics in which Aristotle mentions

what elsewhere, and especially in the Metaphysics, he considers to be a paradigmatic instance of a

result that may occur ἀπὸ τοῦ αὐτομάτου, namely, of the production of health by the warmth of the

wind or the sun. This aspect of the passage is even more important if we consider that, in the

Metaphysics, Aristotle takes the production ἀπὸ τοῦ αὐτομάτου of health to be analogous to the

136

Phys. B 5, 197a 21-24.

136

spontaneous generation of living beings – another topic which is also mentioned only in a brief and

parenthetic remark in the Physics. As we have seen, in fact, in Physics B 6 Aristotle mentions

occurrences of τὸ αὐτόματον in natural generations as being ‘the furthest separated from what

occurs ἀπὸ τύχης’ in order to suggest that the phenomenon in question goes beyond the scope of the

investigation he is undertaking.

A second oddity of this passage is that it is the only occasion where Aristotle talks of health

as capable of being restored by τύχη. In every other passage in which he considers the possibility of

health being caused by the heat of the sun or the warmth of the wind – the same causes responsible

for the spontaneous generation of living beings – Aristotle consistently speaks of health being

restored ἀπὸ ταὐτομάτου, an expression that conforms to the language of medical literature.

A straightforward explanation for this may be that in Physics B 5, the source of the passage

in question, Aristotle simply seeks to provide a general account of chance, and he uses the terms

τύχη and τὸ αὐτόματον interchangeably, with no variation in meaning, in order to do so. In support

of this explanation, one may be tempted to call upon the passage of Metaphysics Z 7, in which

Aristotle claims that health is the sort of thing that may come to be “καὶ ἀπὸ ταὐτομάτου καὶ ἀπὸ

τύχης”.137

Yet, clearly this passage of the Metaphysics does not fit such an interpretation, for it is

hardly the case that Aristotle uses the terms τύχη and τὸ αὐτόματον interchangeably and with the

same meaning when he claims that health can be produced ‘both ἀπὸ ταὐτομάτου and ἀπὸ τύχης’.

If anything, in fact, the Metaphysics suggests that there is a difference between health being

restored ἀπὸ ταὐτομάτου and health being restored ἀπὸ τύχης, and this in turn suggests that the

problem raised by Aristotle in the Physics arises precisely because the terms τύχη and τὸ αὐτόματον

are used interchangeably, when they should instead be distinguished. Indeed, it is more plausible to

think that in the Metaphysics Aristotle uses the term τὸ αὐτόματον in a different sense, and more

precisely, in the sense ‘furthest separated from what occurs ἀπὸ τύχης,’ which applies primarily to

137

Metaph. Z 7, 1032a 28-29.

137

the generation of living beings without seed, and by analogy, to the production of health without the

actions of a doctor.

It is in fact possible to discern a significant difference between health being restored ἀπὸ

τύχης and health being restored ἀπὸ ταὐτομάτου precisely by distinguishing between causes κατὰ

συμβεβηκός and the στέρησις of synonymous causation. This distinction is actually the key to

understanding not only why the example of health in the Physics poses a difficulty for Aristotle’

analysis of chance, but also why it is only the recovery of health ἀπὸ ταὐτομάτου that is considered

analogous to the spontaneous generation of living beings. Aristotle provides evidence to this effect

in a passage of Metaphysics E 2, a chapter entirely dedicated to the analysis of ὄν κατὰ

συμβεβηκός, in which he considers the following case:

A pastry-baker, who aims at making tasty food, may make something which produces health, but he

does not so in virtue of the art of pastry-making; so we say that this occurred κατὰ συμβεβηκός, and

while there is a sense in which he makes it (καὶ ἔστιν ὡς ποιεῖ), in an unqualified sense he does not

make it (ἁπλῶς δ’ οὔ).138

The situation described above meets all the criteria of accidental causation that Aristotle sees at play

in the occurrence of events attributed to chance, and as such, offers a paradigmatic instance of a

recovery of health that strictly speaking is brought about ἀπὸ τύχης.

In this example, just as in the Physics’s example of the debtor’s lucky recovery of money,

Aristotle identifies the recovery of health ἀπὸ τύχης as the accidental outcome of the attempted

realization of a different goal, namely, that of making pleasant food. From the point of view of the

example provided in Metaphysics E, the recovery ἀπὸ τύχης of health does not pose a conundrum,

but instead offers a perfect example of Aristotle’s general account of chance as an accidental cause.

In the Physics, in fact, Aristotle points out that although “there is a way in which things come to be

by chance (ἔστιν ὡς γίγνεται ἀπὸ τύχης), for they come to be by virtue of accident (κατὰ

συμβεβηκὸς γὰρ γίγνεται), and τύχη is an accidental cause”, nonetheless “in an unqualified sense it

138

Metaph. E 2, 1027a 3-5.

138

is the cause of nothing (ὡς δ’ ἁπλῶς οὐδενός)”.139

But this is the very same point that the example

of the Metaphysics is meant to show, when Aristotle says that although “there is a way in which the

pastry-baker does make something healthy (ἔστιν ὡς ποιεῖ)”, for he makes it by virtue of accident,

nonetheless “in an unqualified sense a pastry-maker does not make healthy things (ἁπλῶς δ’

οὔ)”.140

This explains why pastry-baking produces health ‘neither always nor for the most part’ and

why occurrences of this sort are unpredictable, unaccountable, and inscrutable to human thought.

Furthermore, and again as Aristotle claims in the Physics, for the same reasons that accidental

causes of the recovery of health are logically indeterminate, they are also potentially unlimited, so

that any other art which is not medicine has the potential of becoming the accidental cause of

health. This is precisely what Aristotle claims in the Metaphysics. In a different passage of

Metaphysics E 2, Aristotle explains that this is so because the accidental attributes that come into

being with the proper products of a certain art are potentially infinite:

He who produces a house does not produce all the attributes that come into being along with the

house; for these are innumerable (ἄπειρα γάρ ἐστιν); the house that is made may be pleasant for

some people, harmful to some, and beneficial to others, and different – to put it shortly – from all

things that are; but the art of building does not aim at producing any of these attributes.141

It is clear, then, that had Aristotle considered the example of a pastry-baker healing someone

accidentally, the case of the recovery of health by chance in the Physics would not have posed a

particular challenge to his general theory. Indeed, there seems to be no particular difficulty in

saying that virtually ‘any random thing (τὰ τυχόντα)’ could come to be the accidental cause of

health. In principle, there is no more reason to suspect that a barber, who aims at cutting hair, is less

likely to be the accidental cause of health than a pastry-baker, who aims at making pleasant food, or

a house-builder, who aims at building houses, ‘for an unlimited number of things coincide in one

139

Cfr. Phys. B 5, 197a 12-14. 140

Cfr. Metaph. E 2, 1027a 3-5. 141

Metaph. E 2, 1026b 6-10. Cfr. the discussion of this passage in FREDE [1992], pp. 41-43.

139

(ἄπειρα γὰρ ἂν τῷ ἑνὶ συμβαίη)’.142

In fact, virtually any other art, which is not medicine, could

come to be the accidental cause of health. But Aristotle did not do that. Instead, he considered cases

in which the recovery of health is due to the heat of the sun or the warmth of the wind, as he

regularly does when he discusses the recovery of health ἀπὸ ταὐτομάτου.

Even if, in both examples, what is identified as the cause of health is not medicine, and

hence, even if in both cases there is absence of synonymous causation, nonetheless in the example

of Metaphysics E health is said to be produced by another art, which in itself does not have any

power to heal. In the example of the Physics, by contrast, health is said to be produced by the heat

of the sun or the wind – the same cause directly responsible for the spontaneous generation of living

beings – a δύναμις which is indeed productive of health.

In Metaphysics Z 7, in which Aristotle points out the analogy between the production of

health without the action of a doctor and the generation of living beings without seed, the difference

is framed in the following terms:

What is healthy comes into being when the producer has had the following sort of thought (γίγνεται

δὲ τὸ ὑγιὲς νοήσαντος οὕτως): since health is this, then if something is to be healthy, it must have

this – for instance, a uniform condition of the body – and if it is to have this, it must have heat

(θερμότητα). This is how he thinks at each stage, until he leads the process back to the last thing,

which is what he can produce himself, and then the motion from here on toward health is called

production (εἶτα ἤδη ἡ ἀπὸ τούτου κίνησις ποίησις καλεῖται, ἡ ἐπὶ τὸ ὑγιαίνειν). […] Of generations

and movements, then, there are two moments: one part is called thought (ἡ μὲν νόησις καλεῖται) and

the other production (ἡ δὲ ποίησις). That which proceeds from the starting point, that is the form, is

thought (ἡ μὲν ἀπὸ τῆς ἀρχῆς καὶ τοῦ εἴδους νόησις), and that which proceeds from the final step of

the thinking is production (ἡ δ’ ἀπὸ τοῦ τελευταίου τῆς νοήσεως ποίησις). […] The productive

principle, then, and the starting-point for the process of becoming healthy (τὸ δὴ ποιοῦν καὶ ὅθεν

ἄρχεται ἡ κίνησις τοῦ ὑγιαίνειν), if it happens by art (ἂν μὲν ἀπὸ τέχνης), is the form in the soul (τὸ

εἶδός ἐστι τὸ ἐν τῇ ψυχῇ), but if it happens ἀπὸ ταὐτομάτου, it comes from whatever is the principle

of the production for one who produces by art (ἀπὸ τούτου ὅ ποτε τοῦ ποιεῖν ἄρχει τῷ ποιοῦντι ἀπὸ

τέχνης). In medical treatment, for instance, the principle is presumably from warming (ὥσπερ καὶ ἐν

τῷ ἰατρεύειν ἴσως ἀπὸ τοῦ θερμαίνειν ἡ ἀρχή), which the doctor produces by rubbing.143

In what ought properly to be called the production of health ἀπὸ τύχης, therefore, the accidental

cause of health is another art. Accordingly, as we have seen in such cases, although ‘there is a sense

142

Phys. B 5, 196b 29. 143

Metaph. Z 7, 1032b 15-26.

140

in which such an art produces health (ἔστιν ὡς ποιεῖ)’, since it produces it by accident, in an

unqualified sense (ἁπλῶς), it does not produce anything, and this explains why pastry-bakers,

house-builders, or barbers produce health ‘neither always nor for the most part’. But in the case of

the production of health that is more aptly described as occurring spontaneously – in analogy with

the generation of living beings without seed – as when someone is healed by the heat of the sun

(εἵλησις), the cause of health ‘comes from whatever is the principle of the production for the one

who produces it by art (ἀπὸ τούτου ὅ ποτε τοῦ ποιεῖν ἄρχει τῷ ποιοῦντι ἀπὸ τέχνης)’. We are not

here referring to an accidental cause – at least, not in the same sense in which pastry-baking or

house-building is an accidental cause – for we cannot say that the heat of the sun produces health

only ‘in a way’, but in an unqualified sense, it does not produce health. Rather, heat is the proper

starting point (ἀρχή) for the production (ποίησις) of health; it is the active principle and that from

which the process of becoming healthy begins (τὸ δὴ ποιοῦν καὶ ὅθεν ἄρχεται ἡ κίνησις τοῦ

ὑγιαίνειν). Doctors know that such a δύναμις always or for the most part produces health in certain

patients, and therefore, may recommend it in order to treat certain ailments.

The same point can also be made by expanding upon Aristotle’s pastry-baking example of

Metaphysics E 2. We say that if a pastry-baker heals someone who happens to have a fever by

offering him some honey-water in order to please him, then the pastry-baker can be said to have

healed that person by chance. However we cannot say that honey-water healed that person by

chance, since “for the most part honey-water is beneficial to a patient with a fever”.144

Had the

pastry-maker known that, he would not have healed the person by chance since in that case he

would have healed him using a form of medical skill.

We can see, then, that the difficulty that Aristotle seeks to draw to our attention in his

account of chance in the Physics originates in the fact that the example he considers is not a case of

recovery of health by chance at all, that is, it does not fit the Physics’ account of τύχη and τὸ

144

Metaph. E 2, 1027a 23-24.

141

αὐτόματον because it is not a case of health being caused κατὰ συμβεβηκός, but rather only in the

absence of synonymous causation, which shows that the two cases are not equivalent. The tentative

tone of the parenthetic passage of the Physics reveals that the ἀπορία concerning the recovery of

health by the heat of the sun or the warmth of the wind is not yet fully developed and resolved. Had

Aristotle considered the accidental production of health through the actions of a practitioner of

another art in the pursuit of another goal – a genuine cause κατὰ συμβεβηκός of health – he would

have had no problem admitting that health can be produced by an unlimited number of causes, and

hence, by virtually ‘any random thing.’

Instead, the example of health being restored by virtue of the heat of the sun or the warmth

of the wind fits the account of τὸ αὐτόματον that is ‘the furthest separated from what occurs ἀπὸ

τύχης’, which is the focus of Metaphysics Z 7-9, and it is used in analogy with the spontaneous

generation of living beings. Thus, when in Metaphysics Z 7 Aristotle claims that health is the sort of

thing that may be produced ‘both ἀπὸ ταὐτομάτου and ἀπὸ τύχης’, he shows that he is aware of

these two different possibilities.145

In this context, therefore, τὸ αὐτόματον is not chance, and hence,

it is not used in the same sense as in the Physics, because it is not an accidental cause in the sense

required by the Physics.

These key considerations enable us to understand the following challenging passage of

Metaphysics Z 9, the meaning of which would otherwise remain obscure:

It is also clear from what has been said that in a way (τρόπον τινά) everything (πάντα) comes to be

either from something of the same name, as things that are generated by nature (for example a house

comes from a house, in so far as it is brought into being by thought; for the skill is form), or from a

part of itself, or from something which possesses a part of it (ἢ ἐκ μέρους ἢ ἔχοντός τι μέρος) – that

145

Aristotle presents another interesting and amusing example of this distinction in Hist. An. VI 2, 559a 30 – 559b 6,

concerning the spontaneous hatching of fowl eggs. He claims that “eggs are hatched by the incubation of the mother-

bird, but they can also hatch spontaneously (οὐ μὴν ἀλλὰ καὶ αὐτόματα).” The report is immediately followed by the

curious story of “a drunkard (φιλοπότης τις) in Syracuse, who put eggs into the ground under his rush-mat and kept on

drinking until he hatched them (ἕως ἐκλέποι τὰ ᾠά).” It is not difficult to see the difference between eggs being hatched

spontaneously, that is without the action of the mother bird, by the warmth of the sun or the wind, and eggs being

hatched by chance by a drunkard. The same story is told by Pliny in his Nat. Hist. X, 152-153. Aristotle also give a

report about the expertise of Egyptian farmers in hatching eggs artificially. The importance of this report (whose

veracity was doubted up to the nineteenth century CE) for the history of embryology is stressed by NEEDHAM [1931],

p. 45 ff.

142

is, unless it comes to be by accident (ἐὰν μὴ κατὰ συμβεβηκὸς γίγνηται). For the primary cause of

the production, the cause in its own right, is a part of what is produced (τὸ γὰρ αἴτιον τοῦ ποιεῖν

πρῶτον καθ’ αὑτὸ μέρος). Thus the warmth in the movement produced warmth in the body, and this

either is health, or is a part of health (ἢ μέρος), or is followed by health itself or some part of health.

That is why it is said to produce health (ὅτι ἐκεῖνο ποιεῖ), namely because it produced that on which

health follows and to which it belongs.146

Although many of the details in this passage have been the subject of dispute, the central elements

of Aristotle’s discussion are quite straightforward. To begin with, this passage constitutes the

closing remark of the broader section in Metaphysics Z 9 in which Aristotle considers the

conditions under which some of the things that are produced by art can also be produced ἀπὸ τοῦ

αὐτομάτου. It is only at the end of this section that Aristotle shifts perspectives to consider the

analogous conditions under which living creatures can be produced ἀπὸ τοῦ αὐτομάτου.

Hence the subject of the first sentence – πάντα – clearly refers to everything that may be the

product of art, which includes both things that are actually produced by art and things that are

produced ἀπὸ τοῦ αὐτομάτου.147

Aristotle makes these two alternatives explicit by stating that the

kind of things which may be produced by art may either come to be from something of the same

name (ἐκ συνωνύμου),148

or ‘from a part of itself or from something which possesses a part of it (ἢ

ἐκ μέρους ἢ ἔχοντός τι μέρος)’.149

The second half of this passage, introduced by the explanatory γάρ, shows that of the two

stated alternatives – that is, either ‘ἐκ συνωνύμου’ or ‘ἢ ἐκ μέρους ἢ ἔχοντός τι μέρος’ – the latter

alternative is the one which describes the production of things ἀπὸ τοῦ αὐτομάτου. This is clear

from the example which immediately follows, namely, the restoration of health by heat, for

Aristotle claims that heat (ἡ θερμότητα) is ‘either health, or part of health (ἢ μέρος), or is followed

146

Metaph. Z 9, 1034a 21-30. I have adopted, with some modifications, the translation proposed by Bostock, who

deletes ἢ ἐκ μέρους ὁμωνύμου from 1034a 23 and retains ἢ ἐκ μέρους at line 1034a 24. 147

This opinion is shared by ROSS [1924], p. 191; BOSTOCK [1994], p. 137; and REALE [2004], p. 1043, among

others. 148

As noted above (Part II, Chapter 2), in this passage Aristotle uses the expression ‘ἐξ ὁμωνύμου’. However, as ROSS

[1924], p. 192 and 355 has pointed out, in this context Aristotle uses the expression ‘ἐξ ὁμωνύμου’ loosely, and in the

ordinary Greek usage, in the sense of ἐκ συνωνύμου. 149

As ROSS [1924], p. 191 and BOSTOCK [1994], p. 137 have noted, the reference to the ‘things that are generated by

nature (τὰ φύσει)’ is used only as a comparison, and not as an example, of things that come to be ἐκ συνωνύμου, for

Aristotle makes it clear that they come to be ‘in a way (τρόπον τινὰ)’ from something of the same name.

143

by health or by some part of health’. The language employed by Aristotle to describe the way in

which heat is a cause of health matches exactly the previous considerations on the same subject in

Metaphysics Z 7. There, as we have seen, Aristotle claims that when health is produced ἀπὸ

ταὐτομάτου, the productive principle (τὸ ποιοῦν) and starting point (ἡ ἀρχή) of the production of

health is heat, or “whatever is the principle of the production for one who produces by art (ὅ ποτε

τοῦ ποιεῖν ἄρχει τῷ ποιοῦντι ἀπὸ τέχνης)”.150

Similarly, in Metaphysics Z 9, Aristotle claims that

heat is ‘the cause in its own right of what is produced (τὸ γὰρ αἴτιον τοῦ ποιεῖν πρῶτον καθ’ αὑτὸ)’.

Bostock, who endorses this reading of the passage, claims that Aristotle “gives us a very

straightforward contrast: it is the things produced by skill that come from something of the same

name (i.e. the form in the mind of the producer), and things produced spontaneously that come from

a part (or what has some part), for example health from warmth”.151

Yet, some lines further in his

commentary, Bostock adds that “the final caveat ‘unless it comes to be coincidentally’ may be

ignored”, as it either begs the question, or else makes a point entirely unrelated to the topic under

scrutiny.152

The caveat stated by Aristotle, however, is extremely important, and if we ignore it, we may

be unable to understand the significance of the passage as a whole. Indeed, Aristotle’s remark is all

the more important since it is the only reference that he makes to κατὰ συμβεβηκός causation

throughout Metaphysics Z 7-9. With this remark, in fact, Aristotle aims to show that the two

alternatives that he lays down for everything (πάντα) which may be the product of art, namely,

‘either from something of the same name, or from a part or from something which possesses a

part’, apply only to things that are not produced κατὰ συμβεβηκός.

This point is in fact crucial in Aristotle’s argument, for when he says that everything which

may be the product of art is produced either from something of the same name or from a part unless

150

Metaph. Z 7, 1032b 15-26. 151

BOSTOCK [1994], p. 137. 152

BOSTOCK [1994], p. 137.

144

something is produced κατὰ συμβεβηκός, he is recognizing that what may be produced by art can

actually be produced in three different ways: either τέχνῃ, or ἀπὸ ταὐτομάτου, or κατὰ

συμβεβηκός. If we return to the example of health, this statement becomes clear: Aristotle

recognizes the fact that health can be produced either by a doctor (ἐκ συνωνύμου), or from heat

(ἀπὸ ταὐτομάτου), or by a pastry-baker (κατὰ συμβεβηκός).153

The latter possibility is an instance

of health being produced ἀπὸ τύχης, so that health is something that can be produced either by art,

or spontaneously, or by chance. Although Aristotle merely mentions the possibility of health being

restored κατὰ συμβεβηκός, it is clear that he mentions it as something that falls beyond the scope of

investigation of Metaphysics Z 7-9.

Aristotle’s remark has at least three important consequences. To begin with, this statement

shows that when in Metaphysics Z 7 Aristotle claims that health can be produced ‘both ἀπὸ

ταὐτομάτου and ἀπὸ τύχης’, he is clearly taking these two options as two distinct possibilities.

Secondly, the whole discussion of Metaphysics Z 7-9 shows that Aristotle is concerned only with

what comes to be ἀπὸ ταὐτομάτου, and not with what comes to be ἀπὸ τύχης. Finally, and most

importantly, Aristotle’s remark shows beyond any doubt that the account of τὸ αὐτόματον in

Metaphysics Z 7-9 is different from the account given in Physics B 4-6 in that it does not conform

to Aristotle’s account of chance as an accidental cause. In the Metaphysics, in fact, the production

of health ἀπὸ ταὐτομάτου is not subsumed under the mode of production of health κατὰ

συμβεβηκός, but contrasted with it, and hence it cannot be thought of as an ‘accidental cause of

what may be produced by thought’ in the sense of the Physics. The Metaphysics states that unless

something is produced κατὰ συμβεβηκός, it will be produced either τέχνῃ or ἀπὸ ταὐτομάτου. But

this means that τὸ αὐτόματον is not, in this context, a cause κατὰ συμβεβηκός. And in fact, unlike a

pastry-baker, who is only a cause κατὰ συμβεβηκός of health, the heat of the sun or the warmth of

153

ROSS [1924], p. 192 adopts a similar interpretation, and notes that “incidental production may be illustrated by the

case of the builder’s producing not a house simply (which he produces directly) but a house which is agreeable or

injurious to its inmates”.

145

the wind responsible for the recovery of health ἀπὸ ταὐτομάτου is explicitly recognized as a cause

καθ’ αὑτὸ of the production of health.

In this way, then, Metaphysics Z 7-9 makes known the conceptual elements required to

resolve the ἀπορία raised in Physics B 5. In the passage in question of the Physics, Aristotle

mistakenly conflates an instance of recovery of health ἀπὸ ταὐτομάτου in the sense used in the

Metaphysics – namely, the recovery of health because of ‘the breath of the wind or the warmth of

the sun’ – with the recovery of health ἀπὸ τύχης in the sense explained in the Physics – namely, by

luck or chance. As we have seen, an appropriate instance of the latter phenomenon would be the

recovery of health due to the actions of a pastry-baker, that is, a case of recovery that falls under the

heading of τὸ αὐτόματον understood as a cause κατὰ συμβεβηκός of what may be produced by

thought or nature. Yet, in the example of Physics B 5, the recovery of health is not due to accidental

causes, but to the very same δύναμις that is ‘the ἀρχή of the production for the one who produces it

according to medicine’.

146

7. The Equivocity of τὸ αὐτόματον: Chance and Spontaneity

Ever since Balme’s unprecedented study of spontaneous generation in Aristotle’s biology,

prominent scholars have insisted that there is an irreconcilable contradiction between Aristotle’s

alleged ‘theoretical’ account of spontaneity, supposedly elaborated in Physics B 4-6 and endorsed in

Metaphysics Z 7-9, and his ‘biological use’ of spontaneity in scientific practice, defended, most

notably, in the Historia Animalium and De Generatione Animalium. However, a close analysis of

spontaneous generation in Aristotle’s biological works and a detailed reading of the account of τὸ

αὐτόματον in the Physics and Metaphysics reveal the error of this position, and help us to reach a

different understanding of the complexities present in Aristotle’s texts.

In truth, there is no inconsistency between the Metaphysics’ account of spontaneous

generation and the account presented in the biological works. As we have seen, the Historia

Animalium and the De Generatione Animalium constitute the very source of the account presented

in Metaphysics Z 7-9, so much so that the views presented in the Metaphysics can only be correctly

understood when we perceive them as reflections of precisely the sorts of phenomena studied in the

biological works.154

Moreover, the causal account of spontaneity in Metaphysics Z 7-9 does not

correspond to the analysis of τὸ αὐτομάτον in Physics B 4-6, which shows that the ordinary

distinction between a unified ‘theoretical’ account of spontaneity and its ‘biological’ counterpart

conceals Aristotle’s thought rather than clarifies it.155

An alternative and more promising approach to understanding these differences would be to

recognize that Physics B 4-6 and Metaphysics Z 7-9 concern themselves with different sorts of

phenomena: while the Physics deals with the phenomenon of chance, the Metaphysics deals with

the phenomenon of spontaneity. Although in the Greek language these different phenomena have a

name in common – they both fall under the heading τὸ αὐτόματον – the “definition of being which

154

Cfr. Part II, Chapter 3. 155

Cfr. Part II, Chapter 6.

147

corresponds to the name is different”,156

and hence, we ought to acknowledge them as equivocal

phenomena.157

By rejecting the belief that spontaneity can be subsumed under the category of

chance, we recognize that in the different treatises, Aristotle considers different phenomena

altogether, so that the question of inconsistency in Aristotle’s diverging accounts of τὸ αὐτόματον

does not arise.

Thus, the matter at hand can be correctly understood only by realizing that in Metaphysics Z

7-9 and Physics B 4-6, Aristotle is concerned with different problems, and that the definition of τὸ

αὐτόματον in the Physics allows Aristotle not to defend his own hypothesis of spontaneous

generation, as it is commonly thought, but to criticize the different hypothesis of generation by

chance. This goes against the assumption, held by proponents of the standard interpretation, that

Aristotle endorses the view concerning the generation ἀπὸ τοῦ αὐτομάτου of living beings which is

implied by the analysis of the Physics.

This difference has been generally overlooked by Aristotelian scholars, who have failed to

appreciate the different problems, contexts, methods, and intentions behind the Physics’ and the

Metaphysics’ accounts of τὸ αὐτόματον. In fact, while the Metaphysics, which rests on hypotheses

developed in the context of medical science, engages in a positive discussion of the biological

hypothesis of the spontaneous generation of living beings, which Aristotle endorses in his

biological works, the Physics, which targets hypotheses developed in the context of natural

philosophy, engages mainly in a polemical discussion against the zoogonical hypothesis of the

origin of living beings by chance, which Aristotle rejects in his biological works. What we ought to

realize is that Aristotle believes that living creatures can be generated spontaneously, but not by

chance.

To be clear, the distinction between the two equivocal phenomena that share the name ‘τὸ

αὐτόματον’ is not the same as the distinction made by most Aristotelian scholars between the

156

Cat 1, 1a 1-2. 157

Cfr. PANAYIDES [2013].

148

‘generic’ concept of chance and the alleged ‘specific’ concept of spontaneity. As we have seen,

many authors argue that in the Physics, Aristotle distinguishes a generic sense of τὸ αὐτόματον as

‘the accidental cause of the sort of things which might come to be for the sake of something (ὅσ’ ἂν

γένοιτο ἕνεκά του)’ from a specific sense as ‘the accidental cause of the sort of things which might

come to be from nature (ὅσα ἂν πραχθείη ἀπὸ φύσεως)’. Yet, as we have pointed out, there is no

textual foundation for such a distinction in the Physics.158

The proper phenomenon of τὸ αὐτόματον as spontaneity is described by Aristotle in

Metaphysics Z 7-9 and is used to refer both to the generation of living beings without seed and to

the recovery of health without the action of a doctor, in conformity with its use throughout his

biological works. This, however, is not a specification of the general phenomenon of τὸ αὐτόματον

as chance described by Aristotle in Physics B 4-6, since Aristotle does not consider it to be an

accidental cause in the sense required by the Physics. This point, as we have seen, is made explicit

in Metaphysics Z 9, where Aristotle clearly states that the generation ἀπὸ τοῦ αὐτομάτου under

consideration is not a form of generation κατὰ συμβεβηκός, and is further supported by the Historia

Animalium, where the generation ἀπὸ τοῦ αὐτομάτου of insects – far from being considered as

occurring κατὰ συμβεβηκός – is said to occur κατὰ φύσιν.

This proves the equivocity of τὸ αὐτόματον, that is, the fact that certain phenomena that

have a name in common nonetheless have a ‘different definition of being corresponding to the

name’. The criterion presented by Aristotle in the Physics, namely, that τὸ αὐτόματον is a cause of

what comes to be ‘neither always nor for the most part’, and which derives from the very fact that in

the Physics τὸ αὐτόματον is considered as a cause κατὰ συμβεβηκός, is introduced as an essential

element of τὸ αὐτομάτον precisely in order to identify the particular sense of the term which he is

concerned with in that particular context – the sense that describes the general phenomenon of

chance – and to distinguish it from an equivocal, more traditional and, as we shall see, more widely

158

Cfr. Part II, Chapter 5.

149

used sense of the term – the sense that describes the phenomenon of spontaneity – which is only

marginally connected with the phenomenon of chance.159

Although the difference between the two senses of τὸ αὐτόματον is never the subject of

explicit comparison, Aristotle nonetheless acknowledges their distinction. In the Physics, for

instance, Aristotle recognizes a different sense of τὸ αὐτόματον when instead of looking at it from

the point of view of the motion of natural things, he mentions its role in the generation of living

beings. With this, Aristotle recognizes the phenomenon of spontaneity, yet sets aside its study as

beyond the scope of the task that he is undertaking, which only concerns itself with the different

phenomenon of chance.

Although this distinction may appear rather tentative in the Physics, that is, although

Aristotle may not have worked out a full articulation of the distinction between the two equivocal

phenomena, he nevertheless recognizes its existence by claiming that the role of τὸ αὐτόματον in

natural generations is ‘μάλιστα χωριζόμενον τοῦ ἀπὸ τύχης’ – ‘the most separated from what is ἀπὸ

τύχης’.160

This provides us with a criterion – the proximity or distance to τύχη – to distinguish the

two different meanings of the term τὸ αὐτόματον.

If Aristotle recognizes but then sets aside the study of τὸ αὐτόματον which is ‘the most

separated from what is ἀπὸ τύχης’, that is because the focus of his investigation in the Physics is a

sense of τὸ αὐτόματον which is ‘the least separated from what is ἀπὸ τύχης’. This formulation

ought not to be surprising. Aristotle knows that τὸ αὐτόματον and τύχη are used indiscriminately

and interchangeably to describe the general phenomenon of chance, and throughout Physics B 4-5

he follows such an indistinct use of the terms. And in Physics B 6, where Aristotle draws a

distinction between the two terms, he does not introduce a different and ‘separate’ sense of τὸ

αὐτόματον, but only claims that τὸ αὐτόματον ‘applies to more things’ than τύχη, and that, properly

speaking, τύχη ought to apply only to subjects capable of εὐτυχία and ἀτυχία. In fact, even when

159

Cfr. Part II, Chapter 8. 160

Phys. B 6, 197b 32-33.

150

such a distinction is drawn, Aristotle does not hesitate to claim that ‘by virtue of similarity (καθ’

ὁμοιότητα)’ everything which occurs ἀπὸ τοῦ αὐτομάτου can ‘in a way (πως)’ be said to happen

ἀπὸ τύχης, as confirmed by all the examples he provides; and this, too, is readily explainable, since

the determination of the general structure of what comes to be ἀπὸ τοῦ αὐτομάτου is achieved

through the analysis of a specific example of occurrence ἀπὸ τύχης – the example of the man

recovering ἀπὸ τύχης his money – which is an instance of what can occur ἀπὸ τοῦ αὐτομάτου to

things to which we can ascribe εὐτυχία and ἀτυχία.

Hence, when it is ‘least separated from τύχη’, τὸ αὐτόματον refers to the general

phenomenon of chance, whereas when it is ‘most separated from τύχη’, it refers primarily to a

particular form of natural generation, and this is the sense that properly encapsulates the

phenomenon of spontaneity. The distinction between the two different senses of τὸ αὐτόματον in

terms of their relative association with or separation from τύχη is all the more revealing if we

consider the dialectical context in which the definition of τὸ αὐτόματον in the Physics is achieved.

Consider, for instance, the way in which Aristotle introduces his positive account of τύχη and τὸ

αὐτόματον at the beginning of Physics B 5:

In the first place, then, since we see some things always, and others for the most part, coming to be

in the same way, it is plain that τύχη or what is ἀπὸ τύχης is said to be the cause of neither of these

(οὐδετέρου τούτων αἰτία λέγεται) – neither of that which is by necessity and always, nor of that

which is for the most part. But since there are other things which come to be besides these (παρὰ

ταῦτα), and all men say that these are ἀπὸ τύχης (καὶ ταῦτα πάντες φασὶν εἶναι ἀπὸ τύχης), plainly

there is such a thing as τύχη and τὸ αὐτόματον.161

As rightly observed by ancient and modern commentators alike, Aristotle combines two kinds of

evidence in this argument to justify his assertion that ‘there is such a thing as τύχη and τὸ

αὐτόματον’.162

On the one hand, Aristotle resorts to factual claims derived from empirical

observations – we see (ὁρῶμεν) certain things coming to be always or for the most part in the same

way, and there are (ἔστιν) other things which come to be besides these – on the other hand, he

161

Phys. B 5, 196b 10-15. 162

Cfr. Simplicius, In Phys. 333.36-334.5, HAMELIN [1931], pp. 112-113, and ROSSI [2011], pp. 149-152.

151

appeals to endoxic statements derived from common linguistic practice – no one says (λέγεται) that

τύχη is the cause of what occurs always or for the most part in the same way, and everybody claims

(φασὶν) that τύχη is the cause of things which come to be besides these.

What commentators have failed to observe, however, is that the ἔνδοξα relied upon in this

argument concern only τύχη, not τὸ αὐτόματον. Aristotle never claims that ‘all men say that what

comes to be ἀπὸ ταὐτομάτου comes to be neither always nor for the most part’, or that ‘no one

claims that τὸ αὐτόματον is the cause of what occurs always or for the most part’. Indeed, as we

shall see, far from being ἔνδοξα, such claims would, quite plainly, be false, for the broadness,

vagueness and ambiguity of the term αὐτόματον in the Greek language is such that although it may

be associated with things that happen ‘besides what occurs always or for the most part’, it is more

ordinarily used to describe things that happen regularly, frequently, and as a result of proper causal

connections, that is to say, things that come to be ‘always or for the most part in the same way’.

Hence, if Aristotle is in a position to conclude that ‘there is such a thing as τύχη and τὸ αὐτόματον’,

that is because he is only focusing on one type of phenomena said to occur ἀπὸ τοῦ αὐτομάτου,

namely, that which is similar to, and least separated from, that which occurs ἀπὸ τύχης.

These reflections bring further support to the claim that what distinguishes the two equivocal

phenomena said to occur ἀπὸ τοῦ αὐτομάτου is precisely the criterion according to which τὸ

αὐτόματον is said to be the cause of what comes to be ‘neither always nor for the most part in the

same way’. As we have seen, this criterion does not apply to the generation ἀπὸ τοῦ αὐτομάτου of

living beings either in the sense used in the Physics or according to any other sense recognized by

Aristotle. But since it is an essential element of what Aristotle describes in the Physics as coming to

be ἀπὸ τύχης καὶ ἀπὸ ταὐτομάτου, then the generation of living beings ἀπὸ τοῦ αὐτομάτου is not

‘αὐτομάτον’ in the sense described in the Physics.

The discussion in Metaphysics Z 7-9, which deals precisely with the sense of τὸ αὐτόματον

that falls beyond the scope of inquiry in the Physics, confirms even more clearly than the Physics

152

that Aristotle recognizes the equivocal nature of τὸ αὐτόματον. As we have seen, Aristotle does so

by claiming that the form of generation ἀπὸ τοῦ αὐτομάτου that applies primarily to the generation

of living beings without seed and, by analogy, to the production of health without the action of a

doctor, does not fall within the scope of what occurs κατὰ συμβεβηκός. This explains why in

Metaphysics Z 7-9, things that occur ἀπὸ τοῦ αὐτομάτου are never said to occur ‘neither always nor

for the most part in the same way’, for they are not caused to happen by virtue of accidental causes.

This means that both the Physics and the Metaphysics acknowledge the equivocity of τὸ

αὐτόματον. Just as in the Physics Aristotle recognizes that the phenomenon of τὸ αὐτόματον in the

generation of living beings falls beyond the scope of an inquiry concerning accidental causation, so

too in the Metaphysics Aristotle recognizes that the phenomenon of τὸ αὐτόματον described in the

Physics as an accidental cause falls beyond the scope of inquiry concerning the generation ἀπὸ τοῦ

αὐτομάτου of living beings. In this sense, then, Physics B 4-6 and Metaphysics Z 7-9 complement

each other, and show mutual recognition of their equivocal object of study. Compared to the rather

tentative distinction made between the two senses of τὸ αὐτόματον in the Physics, the Metaphysics

displays a more positive and developed view of their differences, as is made apparent by Aristotle’s

clear distinction between the recovery of health ἀπὸ τύχης and the recovery of health ἀπὸ τοῦ

αὐτομάτου. In the Physics, by contrast, Aristotle treats this distinction as a matter of puzzlement.

After providing a general definition of chance in Physics B 5, Aristotle questions whether

indeed any random thing could come to be the cause of the chance recovery of health, just as in fact

any random thing can come to be the cause of the chance recovery of money from a debtor. The

two cases are at variance, because while the chance recovery of money can be brought about for

virtually an infinite number of reasons, the chance recovery of health, as Aristotle claims in the

Physics, appears to always or for the most part be due to the same causes, namely the warmth of the

sun and the wind. However, in contrast with the doubts expressed in the Physics, in Metaphysics E

2 Aristotle gives an example of a case of the chance recovery of health, which is not at variance

153

with the chance recovery of money: a pastry-maker who aims to give people pleasure could heal

someone by chance, but so could a house-builder who aims to build houses, which implies that

virtually any random thing could come to the cause of the chance recovery of health.

The comparison between the case of health being restored ‘by the warmth of the sun and the

wind’ and health being restored ‘by a pastry-maker’ provides Aristotle with the key to solving the

ἀπορία raised in Physics B 5. In the latter example, the cause of the recovery of health by chance is

said to be a practitioner of another art. This, in itself, is only a cause κατὰ συμβεβηκός in the precise

sense required by the Physics. As an accidental cause, in the absolute sense (ἁπλῶς), pastry-making

is not a cause of health at all, and hence we cannot, as Aristotle says in the Metaphysics, generalize

this particular instance of recovery of health and claim that pastry-makers ‘always or for the most

part’ cure patients with such and such a condition.

Having said that, in the former example Aristotle is in fact considering a case of

spontaneous recovery of health, namely a recovery due to the warmth of the sun and the wind,

which is not an accidental cause, but one of the causes καθ’ αὑτό, and indeed “the active principle

and that from which the process of becoming healthy begins (τὸ δὴ ποιοῦν καὶ ὅθεν ἄρχεται ἡ

κίνησις τοῦ ὑγιαίνειν).”163

No matter how rare episodes of this type may be, we nonetheless can

make general statements and say that the warmth of the sun and the wind for the most part does

help people with such and such a condition. Once we understand that in this second example the

recovery of health ἀπὸ τοῦ αὐτομάτου is not a chance recovery but rather a spontaneous recovery –

in other words, it is not due to an accidental cause – then there is no reason to be puzzled by the fact

that health, when restored ἀπὸ τοῦ αὐτομάτου, is always or for the most part restored because of the

same causes.

The analogy between the spontaneous recovery of health and the spontaneous generation of

living beings presented in the Metaphysics offers further evidence of the close connection between

163

Metaph. Z 7, 1032b 21-22.

154

the account of τὸ αὐτόματον in Metaphysics Z 7-9 and its use in Aristotle’s biological works. Such

an analogy ought to be framed in the broader philosophical context epitomized by the following

well-known passage at the end of De Respiratione:

Our discussion of life and death and kindred topics is now practically complete. But as to health and

disease, not only the physician but also the natural scientist must, up to a point, give an account of

their causes (περὶ δὲ ὑγιείας καὶ νόσου οὐ μόνον ἐστὶν ἰατροῦ ἀλλὰ καὶ τοῦ φυσικοῦ μέχρι του τὰς

αἰτίας εἰπεῖν). The extent to which these two differ and investigate diverse provinces must not escape

us, since facts show that their inquiries share, to a certain extent, a common path (σύνορος). For

those physicians who are cultivated and learned make some mention of natural science, and claim to

derive their principles from it, while the most accomplished investigators into nature generally push

their studies so far as to conclude with an account of medical principles.164

Arguably the most important element that brings medicine and philosophy of nature together is the

common thermal paradigm underlying the account of the causes in each field, as Aristotle himself

clearly shows in many of his treatises on animal physiology – particularly De Respiratione, De

Longitudine et Brevitate Vitae, and De Juventute et Senectute – where he insists on the fact that

thermal equilibrium is essential to both health and life, and that the disruption of such an

equilibrium is what causes sickness and death.

Aristotle often alludes to the connection between the fields of medicine and biology in his

major zoological treatises, especially in Historia Animalium, a treatise in which ecological

considerations are discussed far more extensively than in any other of his works. On many

occasions in this work, Aristotle mentions the role of the environment – different seasons and

different geographical conditions – in the health, life and reproductive cycles of living beings. For

example, he observes that:

Animals do not all thrive at the same seasons, nor do they thrive alike during extremes of weather.

Further, animals of diverse species are in a diverse way healthy or sickly at certain seasons (κατὰ τὰς

ὥρας), and overall the conditions are not the same for all. Birds thrive in times of drought, both in

their general health and in regard to reproduction, and this is especially the case with the pigeon;

fishes, however, with a few exceptions, thrive best in rainy weather. 165

164

De Resp. 21, 480b 21-30. 165

Hist. An. VIII 18, 601b 23-29.

155

Certainly the environmental conditions that happen to be either harmful or beneficial to the different

living beings are not without a margin of contingency, for, as Aristotle claims, “we do not think that

it is the outcome of luck or coincidence that there is a lot of rain in winter, but only if there is a lot

of rain in August; nor that there are heatwaves in August, but only if there is a heatwave in

winter”.166

Even so, it is not accidental or by chance that some species thrive during rainy weather

while others thrive during periods of drought. Identical considerations, as we have seen, are applied

by Aristotle to the environmental conditions that favor or impede both the spontaneous and the

sexual generation of different species of living beings.167

We ought not to overlook the fact that a fundamental common feature of the chance

recovery of health and the spontaneous recovery of health is that in neither case is the cause of

health a doctor, so that both happen in the absence of synonymous causation. Yet only the chance

recovery of health happens because of an accidental cause. This means, in Aristotelian terms, that

the two different senses of τὸ αὐτόματον are not cases of absolute equivocity – what Aristotle calls

‘homonyms by chance (ἀπὸ τύχης ὁμώνυμα)’168

– where the same term is used according to two

entirely different accounts with no commonality at all.169

Indeed, this partial overlap of accounts

may explain why in the Physics Aristotle characterizes the sense of τὸ αὐτόματον as spontaneity not

as ‘separated (χωριζόμενον)’, but only as ‘most separated (μάλιστα χωριζόμενον)’ from what is ἀπὸ

τύχης.

Instead of distinguishing between a ‘theoretical’ account of τὸ αὐτόματον and a ‘biological’

application of such a concept, we should instead recognize that Aristotle is concerned with different

sorts of phenomena in different treatises. These different sorts of phenomena pose different sorts of

166

Phys. B 8, 199b 36 – 199a 3. 167

Cfr. Part I, Chapter 5. 168

Cfr. Eth. Nic. I 6, 1095b 26-27. 169

SHIELDS [1999], p. 28 ss. groups all the non-radical forms of equivocity under what he calls ‘associated

homonyms’, which are the sorts of things that share the same name yet are defined by two differing accounts, and

which nevertheless overlap to some degree, though not completely.

156

problems, which emerge from the confrontation with different sorts of interlocutors, and their

solution requires different sorts of strategies.

In the biological works, the biological hypothesis of the generation ἀπὸ τοῦ αὐτομάτου of

living beings from the earth and the sea at certain times of the year, under specific meteorological

circumstances, and from distinct environmental conditions, is not based on philosophical or

cosmological principles, but rather finds its source in the information provided by experts of the

‘lower’ arts – fishermen, breeders, farmers etc. – and is accepted by Aristotle in accordance with the

beliefs and the modes of observation of his time. He did not feel the need to defend the existence in

nature of generation ἀπὸ τοῦ αὐτομάτου, since there was no real controversy about its existence.

The controversies, problems, and critical discussions arose only with respect to the scope of τὸ

αὐτομάτον. They concerned the validity and accuracy of the observations of the modes of

generations of each species, and hence, he resolved them at the empirical level with a rigorous and

methodical control of the phenomena.

More importantly, the generation from the earth and the sea of living creatures is never seen

as uncommon, rare, or inscrutable to human understanding, but instead is perceived as a common

aspect of nature, and hence, as frequent, regular, and cyclical as all other forms of natural

generation. This is the main reason why in Aristotle’s biology the term αὐτομάτον, used to describe

such a form of generation, is never associated with the term τύχη.170

The Metaphysics, which analyzes this phenomenon within the framework of a general

discussion of the different modes of coming into being, likewise reveals that Aristotle is not trying

to defend a particular thesis about the generation of animals against alternative theories; instead, he

is attempting to justify the structure of what he considers to be existing realities, that is, of facts,

phenomena, and processes which he considers to be directly available for observation, and in this

respect, the medical account of the spontaneous recovery of health offers a useful comparison.

170

Phys. B 5, 196b 13-15. The term τύχη in fact never appears in the biological works except in De Part. An. I 1, 641b

22, where it is mentioned in the context of a cosmological, not biological, dispute.

157

The discussion of what comes to be ἀπὸ ταὐτομάτου in the Physics, however, is completely

different in character. To begin with, its exposition is a paradigmatic example of dialectical

discussion: it proceeds at a vigorous argumentative pace, its main polemical targets are the

doctrines of previous philosophers, and it is not concerned with a particular biological mode of

generation of living beings, but rather with the general principles of causality. In this context, the

simple empirical observation of phenomena is not sufficient to resolve the disputes and

controversies; what is needed, to begin with, is a thorough philosophical investigation about causes,

and a dialectical analysis of the way in which we speak about causes.171

In this context, Aristotle

must defend the presence of τὸ αὐτόματον against those who deny its existence, and at the same

time reject the opinion of those who make it a cosmological principle of the whole heavens and a

zoogonical principle concerning the origin of living beings.

171

Cfr. Phys. B 4, 196a 11-16: “Many things both come to be and are ἀπὸ τύχης and ἀπὸ ταὐτομάτου, and though not

unaware that each of them can be ascribed to some cause (as the old argument said which denied τύχη), still, all men

say (φασι πάντες) that some things are ἀπὸ τύχης, and others not.”

158

8. The Spontaneous Generation of Living Beings

The use of ‘τὸ αὐτόματον’ to describe spontaneous phenomena in ordinary Greek language is

arguably far more common than its equivocal use to describe phenomena due to chance. A brief

overview of some of the most significant examples of such use validates the equivocal solution here

proposed. Indeed, one of the most interesting observations that can be made about the ordinary use

of the term ‘τὸ αὐτόματον’ is that it is closely connected to human artistic and productive practices.

Before we can appreciate how the term ‘τὸ αὐτόματον’ may have come to describe the

generation of living creatures without seed in Aristotle, we ought to acknowledge that, according to

Aristotle’s explicit testimony, the hypothesis according to which some living beings are regularly

and cyclically generated without seed from the elements in the land and the sea, or from parts or

residues of other animals or plants, finds its source precisely in the experience of men of the ‘lower’

arts – farmers, fishermen, weavers, butchers etc. – from which Aristotle gathers much of the

information of his zoology.

Arguably, the reason for this is the fact that all of the creatures that Aristotle believes to be

spontaneously generated are inextricably intertwined with human activities and practices. Most, if

not all, of the shellfish that Aristotle studies are in fact edible, and much of the knowledge that he

gains about their periods of generation and growth comes from fishermen.172

Valuable information

about spontaneously generated fishes, as the eel, comes from the practice of eel-breeders

(ἐγχελυοτρόφοι).173

The purpura (πορφύρα) – the single spontaneously generated creature most

studied by Aristotle – is collected and used to produce a purple dye, and much of the knowledge

about its generation, anatomy, and health comes from dyers.174

The collection of information about

the spontaneous generation of insects is no different: in one case – that of the silkworm – Aristotle

172

Cfr. Hist. An. VI 15, 569b 4-9. 173

Cfr. Hist. An. VIII 2, 592a 2-3. 174

Cfr. Hist. An. V 19 547a 4-27.

159

gains his knowledge from weavers.175

Other insects are spontaneously generated in domestic

environments, such as kitchens, butcher shops, and all places where mixed waste is collected.176

Most insects are believed to be spontaneously generated from cultivated plants or livestock, and

knowledge about the particular conditions of their coming into being is important in agricultural

practice, either to prevent their growth in an effort to avoid harm to plantations, or to encourage

their growth for beneficial uses, such as for ‘working up the manure (κατειργάσθαι τὴν κόπρον)’.177

In addition, many spontaneously generated insects, especially those that grow in wells and stagnant

water, are very dangerous to human health, causing serious pains and diseases. Thus, knowledge of

the particular conditions of their generation is crucial to take measures for source reduction through

drainage and irrigation, for example.178

It is more difficult, however, to ascertain the origin of the application of the term ‘τὸ

αὐτόματον’ to the phenomenon of the generation of living creatures without seed. To this end, it

may be helpful to consider the ‘higher’ arts and disciplines – poetry, historiography, but especially

medicine – in which the term αὐτόματον is generally used to describe phenomena that are ‘furthest

separated from what is ἀπὸ τύχης’, and, therefore, that can properly be identified as spontaneous.

Perhaps the earliest instance of the use of the term to describe spontaneous phenomena is

found in Hesiod, where it appears twice in The Works and Days, in two very significant contexts. In

the first, Hesiod speaks of the golden age of history when men were endowed with many good

things and during which time “the life-giving earth spontaneously (αὐτομάτη) bore rich and

abundant fruits (πολλόν τε καὶ ἄφθονον)”.179

Although men in this situation can well be deemed to

be lucky, clearly Hesiod does not mean to say that the earth produced fruits by chance, nor that it

did so sporadically or accidentally; on the contrary, the golden age was an age of ‘rich and

abundant’ fruits, which were produced by the earth itself without the need for human toil. In the

175

Cfr. Hist. An. V 19 551b 9-16. 176

Cfr. Hist. An. V 19, 552a 11-15. 177

Cfr. Hist. An. V 19, 552a 20-29. 178

Cfr. Hist. An. V 19, 551b 27 – 552a 11, and Hist. An. I 1, 487b 3-6. 179

Opera et Dies, 117-118.

160

second, different context, Hesiod speaks of the “countless (μυρία)” diseases “spontaneously

(αὐτόματοι)” plaguing human beings “by day and by night”.180

Here again the phenomenon

described as spontaneous is associated with the concepts of frequency and regularity.181

Though it

would be impossible to derive any ‘theory’ or ‘hypothesis’ of spontaneous generation in the form

that Aristotle acknowledges it from these two passages, it is clear that both instances of spontaneity

– in their biological and medical context, respectively – are comparable with Aristotle’s beliefs: he

thinks that many plants are generated from the earth itself ‘by the spontaneous action of nature

(ὥσπερ αὐτοματιζούσης τῆς φύσεως)’,182

and that many diseases are caused by the spontaneous

generation of intestinal worms in humans and animals.183

Herodotus too applies the term ‘τὸ αὐτόματον’ to describe the growth of many plants. For

example, he speaks of the castor berry, which Egyptians cultivate to extract oil, but which ‘grows

wild (αὐτόματα ἄγρια φύεται)’ in Greece;184

of a type of edible grain, which people in India have

no need to plant, because it is ‘spontaneously generated from the earth (αὐτόματον ἐκ τῆς γῆς

γινόμενον)’;185

of hemp, which Thracians use for their garments and which grows ‘both of itself and

by sowing (καὶ αὐτομάτη καὶ σπειρομένη φύεται);’186

and of the gardens of Midas, wherein roses of

surpassing fragrance ‘grow of themselves (αὐτόματα φύεται)’.187

In none of these cases does

Herodotus use the term ‘τὸ αὐτόματον’ to refer to plants that grow from the earth without seed.

Clearly, what he means instead is that all these plants grow without being sown, that is, without the

180

Opera et Dies, 100-104. 181

For an interesting discussion on this passage, cfr. LONGRIGG [1993], pp. 13-19, and LLOYD [2003], pp19-22. 182

Cfr. Hist. An. V 1, 539a 15-25 and De Gen. An. I 1, 715b 25 – 716a 2. 183

Cfr. Hist. An. V 19, 551a 6-13. Note that, as it has been noted by ARMSTRONG [1943], Homer does not accept the

hypothesis of spontaneous generation of insects. In Iliad XIX 23-27, Achilles expresses to Thetis his concerns for the

body of Patroclus, saying “I am terribly afraid that meanwhile flies, burrowing into Menoetius’ brave son through the

bronze-inflicted wounds, may breed worms, and defile the corpse.” Cfr. also MAZZARELLO [1992], who shows that

the reading of this passage of the Iliad influenced Redi’s attack on spontaneous generation and his 1668 masterpiece

Esperienze Intorno alla Generazione degli Insetti, in particular on account of Thetis’ response to Achilles: “My son, be

not disquieted about this matter. I will find means to protect him from the swarms of noisome flies that prey on the

bodies of men who have been killed in battle.” 184

Historiae, II 94, 5-6. 185

Historiae, III 100, 5. 186

Historiae, IV 74, 3. 187

Historiae, VIII 138, 11.

161

need of human toil. However, the crucial aspect of their growing αὐτόματα is that all the plants that

Herodotus mentions are used by human beings for practical purposes, such as for food, to extract

oil, to make garments, or simply for decoration. Thus, plants which grow wild (ἄγριον) are

described as growing αὐτόματον not simply because they grow without human intervention, but

because they could grow for practical purposes as a result of human intervention. Accordingly, the

wild growth of plants meets one – but only one – of the criteria according to the Physics for what

happens ἀπὸ τοῦ αὐτομάτου; namely, it is the sort of thing that could come to be as an outcome of

deliberation and thought. However, since the growth of these plants is not rare, sporadic, or

exceptional, but something which occurs regularly, and on which human communities can stably

rely, no one considers such growth as happening by chance.188

Although in Herodotus the term τὸ αὐτόματον is always used in agricultural contexts, its use

is not restricted to describe the growth of plants, but also extends to other natural phenomena. For

instance, Herodotus claims that in Egypt, “the river rises spontaneously (αὐτόματος), waters the

fields, and then sinks back again; thereupon each man sows his field and sends swine into it to tread

down the seed, and waits for the harvest.”189

Clearly, in this instance, Herodotus is not describing

unpredictable or random cases of flooding, but rather regular, predictable, and cyclical occurrences,

upon which men can rely in their agricultural practices.

Here again, a natural phenomenon, such as the flooding of a river, can be described as

‘spontaneous’ once considered within the context of its practical utilization and contrasted with the

possibility of causing its occurrence artificially. In this instance, too, the use of the term

‘αὐτόματος’ meets one of the requirements of what can be said to occur ἀπὸ τοῦ αὐτομάτου in the

Physics in that it is the sort of thing that could happen as a result of human contrivance. Indeed,

Aristotle himself in the Meteorologica uses the term αὐτόματον in precisely this sense to describe

188

Cfr. Phys. B 5, 197a 2-5: “And in this case the man's coming is said to be the outcome of luck, but if he had chosen

and come for this purpose, or used to come always or for the most part, it would not be called the outcome of chance.” 189

Historiae, II 14, 13-18. Cfr. also IV 53, 11-12, where Herodotus talks of “crusts of salt forming spontaneously

(αὐτόματοι) at the mouth of the river”.

162

the very same phenomenon when he says that “the water from fountains and rivers flows

spontaneously (αὐτόματα), whereas wells need to be worked artificially (τέχνης προσδεῖται τῆς

ἐργασομένης).”190

However, once more, since the phenomena that both Herodotus and Aristotle are

describing happen regularly and predictably, they cannot be considered as happening by chance or

by luck. In these circumstances, it is useful to recall what Aristotle says in the Physics about other

meteorological phenomena:

We do not think that it is the outcome of luck or coincidence (οὐ γὰρ ἀπὸ τύχης οὐδ’ ἀπὸ

συμπτώματος δοκεῖ) that there is a lot of rain in winter, but only if there is a lot of rain in August;

nor that there are heatwaves in August, but only if there are heatwaves in winter.191

The reason why the flooding of a river is said to happen ἀπὸ τοῦ αὐτομάτου, yet not ἀπὸ τύχης, is

not that the beneficial outcome of its occurrence affects things – like plants – that ‘cannot be lucky

and cannot engage in rational activity’. The agricultural context in which cases of this sort are

considered makes it clear that the outcome of the flooding is indeed beneficial to human beings and

the pursuit of their goals. The reasons why we do not think (οὐ δοκεῖ) that such a phenomenon

happens ἀπὸ τύχης is that it happens as it does ‘always or for the most part in the same way’. In

these cases, then, the term ‘αὐτόματον’ is not employed in the sense that is most closely associated

with τύχη, namely chance, but in the sense that is ‘furthest separated from what is ἀπὸ τύχης’,

namely spontaneity.

The sources thus far considered suggest that this sense of the term ‘τὸ αὐτόματον’ was not

only common, but arguably the most dominant usage of the term in Greek, especially in

agricultural contexts like those presented in Herodotus. It is more difficult, however, to establish

whether the men of the ‘lower arts’ used this term to refer to the generation of animals ‘from the

earth,’ or whether such a use was the result of a semantic shift introduced by Aristotle himself to

describe this phenomenon. The latter hypothesis is arguably the most likely. The term ‘τὸ

190

Meteor. II 1, 353b 27-29. 191

Phys. B 8, 198b 36 – 199a 2.

163

αὐτόματον’, in fact, is never used by Aristotle when he gives an explicit account of the opinions of

fishermen and farmers on the generation of creatures without seed; in other words, Aristotle never

claims that ‘some people claim that such animals are spontaneously generated’.192

To understand

why the term could have been employed by Aristotle to describe species of living beings that come

into being without seed, it may be instructive to consider the analogical correlation between this

phenomenon and the growth of uncultivated plants: just as some plants, such as hemp, can grow

either by sowing or of themselves, so, too, certain animals, such as mullets, can come to be either

from seed or of themselves. In the first case, plants are said to grow αὐτόματα when they do so

without man sowing the seeds; in the second, living creatures are said to come to be αὐτόματα when

they come to be without a parent producing the seed.

The two cases are, of course, different in crucial respects. Most relevantly, plants that grow

both wild and by sowing are identical with respect to their species. Aristotle is clear about this point

in De Partibus Animalium, where he claims that “we ought not to divide animals into wild and

domesticated (τῷ ἀγρίῳ καὶ τῷ ἡμέρῳ διαιρεῖσθαι), since this would involve the division of the

same species (ταὐτὰ εἴδη διαιρεῖν), for in a manner of speaking all creatures that are domesticated

are also wild (πάντα γὰρ ὡς εἰπεῖν, ὅσα ἥμερα καὶ ἄγρια τυγχάνει ὄντα)”.193

By contrast, as we have

seen, Aristotle maintains that animals that are generated both with and without seed may have only

a generic identity, but they cannot be considered to belong to the same species.

192

Curiously, however, whenever he provides a direct report on the opinions of fishermen regarding spontaneously

generated animals, he generally uses the verb ‘φύεσθαι’ – ‘to spring forth’ – which is the verb commonly used for

plants and associated with most cases of spontaneity mentioned by Herodotus. In Hist. An. VI 15, 569a 21-22, for

example, when critically assessing the opinion of fishermen regarding the spontaneous generation of the mullet,

Aristotle claims that “some people make the general claim that all mullets grow (ἔνιοι δὲ καὶ ὅλως φασὶ τοὺς κεστρεῖς

φύεσθαι πάντας), but their opinion is wrong”. This language is not infrequent in Aristotle, and at times, he seems to

contrast the verbs γίγνεσθαι and φύεσθαι, reserving the use of the former for the generation from seed, and the latter, for

spontaneous generation. For example, in Hist. An. V 11, 543b 17-18, when giving his own views on the generation of

mullets, he says that “some of them are not generated from copulation (οὐ γίνονται ἐκ συνδυασμοῦ), but grow from

mud and sand (ἀλλὰ φύονται ἐκ τῆς ἰλύος καὶ τῆς ἄμμου).” Similarly, in Hist. An. V 15, 546b 22-24, when he talks of

the purpuras, he says that they are not generated (οὐδὲ γίνονται) from the so-called ‘honeycomb’ that they produce, “but

these and all other shellfishes grow out of mud and decaying matter (ἀλλὰ φύονται ἐξ ἰλύος καὶ συσσήψεως).” 193

De Part. An. I 3, 643b 3-5. Note that the adjective ἥμερος in reference to plants means ‘cultivated’ (cfr. for example

Herodotus’ Historiae V 82, 8; Dioscorides, in De Materia Medica III 148-149, precisely, divides hemp into ἥμερος and

ἀγρία. For a discussion of the categorization of domesticated plants in Aristotle cfr. WARDY [2005].

164

Although the analogy with the wild growth of plants may appear too farfetched as an

explanation for the application of the term αὐτόματον to the generation of living creatures without

seed, we ought nevertheless to recall that it is precisely this analogous use of the term αὐτόματον

that is presented and endorsed by Aristotle in Metaphysics Z 7, where he compares the spontaneous

generation of living creatures with the spontaneous recovery of health.194

Indeed, even the

spontaneous recovery of health is a natural process that can occur without the need of human

intervention. This brings us to the other ‘higher’ art from which Aristotle draws much of the

empirical information of his zoological treatises, namely, Hippocratic medicine.

In the Hippocratic corpus, the term τὸ αὐτόματον appears over a hundred times, and as it has

been rightly observed, on no occasion is the term associated with irregular and sporadic phenomena

or with the results of accidental causal connections.195

On the contrary, spontaneous phenomena in

medicine are considered and studied as entirely regular and predictable natural processes. The

author of De Natura Hominis, for example, claims that:

Most patients (πλεῖστοι) in the condition described above, that is athletic people who have gone soft,

recover their health spontaneously (αὐτόματοι) forty-five days from the day on which they began to

waste. Those of them as exceed this period, should no other illness occur, recover spontaneously

(αὐτόματοι) in a year.196

In the Hippocratic corpus, the term ‘τὸ αὐτόματον’ often refers to a cause, either of disease or of

recovery from a disease, which has not yet been identified197

but which can be discovered by a

careful examination of natural processes leading to it.198

In general, the term is used to identify

natural self-healing reactions of the body – such as vomiting,199

evacuation,200

and blood

194

Cfr. Metaph. Z 7, 1032a 25-32. 195

JOHNSON [2005], p. 105; and [2012], pp 119-126. 196

De Natura Hominis, XII 32-36. 197

Cfr. Aphorismi II 5. 198

Cfr. De Arte VII. 199

Cfr. Aphorismi I 2 and VI 15. 200

Cfr. Aphorismi IV 2 and 21.

165

discharge201

– which a physician can learn to induce artificially, or external natural sources of

healing – such as foods or climatic conditions – which a physician can discern and prescribe to

prevent or cure certain pathological conditions.

In all these instances, the term ‘τὸ αὐτόματον’ is used in the same sense – not an analogous

sense – as the one employed to describe the uncultivated growth of plants. The τέχνη of medicine,

just as of agriculture, ‘either imitates the works of nature or completes that which nature is unable to

bring to completion’. Compare, for instance, Herodotus’ claim that some people in India have no

need to sow the grain from which they find sustenance because ‘it is spontaneously generated from

the earth (αὐτόματον ἐκ τῆς γῆς γινόμενον)’ with the claim by the author of De Prisca Medicina,

according to whom “there is no need for further assistance when the effect of such an agent are

neutralized spontaneously (ἀπὸ ταυτομάτου)”.202

Aristotle’s description of spontaneous phenomena in medical contexts conforms entirely to

all aspects of spontaneity that emerge from medical literature. In fact, Aristotle never includes the

spontaneous recovery of health within the sort of occurrences that happen παρὰ τὸ ὡς ἐπὶ τὸ πολύ,

either in the Physics and the Metaphysics, where he speaks generally about the recovery of health

ἀπὸ ταυτομάτου, or in the zoological works, where he provides specific instances of pathological

conditions being neutralized ἀπὸ ταυτομάτου.203

Neither the authors of the Hippocratic treatises nor

Aristotle himself, therefore, consider the recovery of health by natural causes and without human

intervention to be infrequent or random; in other words, they do not associate the spontaneous

recovery of health with the recovery of health by chance.

This brief overview reinforces the legitimacy of one of the main conclusions of the present

study, namely that the positive account of the biological theory of the generation ἀπὸ ταυτομάτου

of living beings presented in Metaphysics Z 7-9 and endorsed in the biological works – that is to

201

Cfr. Aphorismi IV 78. 202

De Prisca Medicina XVI 36-38. 203

Cfr. Hist. An. VII 1, 587b 19-27, and VIII 24, 604a 29 – 604b 10.

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say, Aristotle’s theory of spontaneous generation – is closely connected to the human productive

domain; arguably, it finds its origins in the agricultural context, and its causal analysis is established

in analogy with medical hypotheses. This account cannot be subsumed under the analysis of τὸ

αὐτόματον in Physics B 4-6, which presents Aristotle’s theory of chance, but rather ought to be

contrasted with it. Aristotle develops his theory of chance in connection with phenomena due to

luck in the practical domain, and uses it mainly for polemical purposes, that is, to reject zoogonical

hypothesis about the origin of living beings.

167

9. The Generation of Living Beings by Chance

The criterion, stated in the Physics, according to which τὸ αὐτομάτον is the cause of what comes to

be neither always or for the most part in the same way, enables us to distinguish processes that

occur spontaneously from those that occur by chance. These two phenomena are, in Aristotelian

terms, equivocal, in the sense that although they both fall under the heading of things that occur

‘ἀπὸ τοῦ αὐτομάτου’, the definition of what it is to be ‘αὐτόματον’, in each of these cases, is

different. They are not, however, equivocal in the radical sense that Aristotle refers to as

‘homonyms by chance (ἀπὸ τύχης ὁμώνυμα)’,204

where the same term is used according to two

radically different accounts. The examples he provides for the chance and the spontaneous recovery

of health reveal that these two phenomena do in fact overlap in a crucial way: in both cases, the

outcome is not brought about by the action of a doctor, although it is the sort of thing that a doctor

could have brought about. Their difference, as we have seen, is explained in terms of accidental

causality. According to Aristotle, the cause of the chance recovery of health, whatever it may be, is

an accidental cause, and hence, is not such as to bring about health either always or for the most

part; by contrast, the cause of the spontaneous recovery of health, whatever it may be, is a genuine

productive principle of health, and hence, is such as to bring about health either always or for the

most part.

As previously mentioned, Aristotle provides both the conceptual tools and some clear

examples to show the difference between a chance process and a spontaneous one in terms of the

sort of things that could have been brought about by art. With respect to the sort of things that could

have been brought about by nature, however, the situation is far more puzzling.

Indeed, while Aristotle provides plenty of instances of the spontaneous generation of living

beings, the apparent absence in Aristotle’s biology of instances of the generation of living beings by

204

Cfr. Eth. Nic. I 6, 1095b 26-27.

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chance is the very reason why he is accused of being inconsistent in his thought. Those who accuse

him of inconsistency claim that the account of chance in the Physics, when applied to the

generation of living beings, implies the belief in random spontaneous generation, that is, the

exceptional generation, without seed, of organisms belonging to species whose members are for the

most part reproduced from seed.

However, as we have seen, Aristotle believes that such an account of chance – which is built

on the practical model of actions due to τύχη, and is seen at work in cases of natural motions –

cannot be applied to natural generations, as he believes to be not only in conflict with empirical

data, but also inconsistent from a purely logical point of view.

This does not mean that Aristotle never conceived of the possibility of the generation of

living creatures by chance, only that he never held it to be true. In fact, the overall polemical

discussion of chance in the Physics reveals that one of Aristotle’s main objectives is to critically

target those who make chance the cause of living beings. In this respect, Aristotle does consider,

reflect upon, and reject the hypothesis of random spontaneous generation in the particular form

endorsed by competing philosophical projects, that is, as the hypothesis concerning the first

generation, without seed, of organisms belonging to species whose members subsequently

reproduce from seed. Thus, properly understood, the Physics should be seen as a work that criticizes

the hypothesis concerning the generation of living beings by chance in much the same way in which

it criticizes the hypothesis concerning the generation of the heavens by chance, in other words, as a

work targeting zoogony as much as cosmogony.205

Once understood in this framework, the hypothesis of the generation of living beings by

chance reveals itself as a consistent target of Aristotle’s criticism. It should, therefore, come as no

surprise that we are unable to find any endorsement of the generation ἀπὸ τοῦ αὐτομάτου of living

beings in the sense implied by the Physics in Aristotle’s biology. To find examples of generation of

205

For the role of chance in some ancient zoogonies and cosmogonies, cfr. GREGORY [2007] and [2009].

169

this sort, we must turn to the criticisms he raises against the accounts of generation of animals found

in the stories of ancient mythologies or in the zoogonies of the physiologoi.

In Aristotle’s biology, as we have seen, the generation from seed and without seed are two

forms of processes that occur according to nature, not by chance, since we observe them as

occurring always or for the most part in the same way: creatures that are spontaneously generated

are always and without exception generated without seed just as creatures that are reproduced from

their own kind are always and without exception generated from seed. What we never see in nature,

however, are creatures that are at first spontaneously generated, and then, begin to reproduce their

own kind from seed.

Ancient myths and many naturalist philosophers before Aristotle, however, relied on this

very hypothesis to explain the origin of living beings. The belief that the living creatures that we

now see reproducing from seed were originally formed from the earth and the sea finds its source in

the ancient cosmogonies of Greece.206

It was still a popular belief during Aristotle’s time, 207

and

arguably the most puzzling feature that he found in the zoogonies of Anaximander, Xenophanes,

and Empedocles.208

Aristotle, consistent with his general attitude toward ancient pronouncements, widespread

beliefs, and the opinions of the learned, refuses to reject these hypotheses outright, even though they

are in radical contrast with his own doctrines. However, since such cosmogonies and zoogonies

provide an account of the generation of living beings that goes beyond (παρά) what we observe

occurring always or for the most part in natural generations, Aristotle proceeds to assert that, for all

these beliefs, the generation of living beings is left to chance. By so doing, Aristotle is in a position

to depict such hypotheses as just that – hypotheses – and hence, avoid declaring them to be false,

while, at the same time, restricting them to the margin of the sphere of rational discourse and

206

Cfr. Theogonia 104-107. 207

Cfr. Phaedo, 96a 6 – 96b 3. Cfr. also McCARTNEY [1920], and SOLMSEN [1958]. 208

Cfr. INWOOD [2001], p. 72 ff.

170

natural science. Emblematic of this attitude is the following passage of De Generatione Animalium

III 11:

Other animals are produced in the form of a grub, not only those bloodless animals which are not

generated from animals (ὅσα μὴ ἀπὸ ζῴων γίγνεται) but even some blooded animals, as a kind of

mullet and some other river fishes and also the eel. For all of these, though they have but little blood

by nature, are nevertheless blooded, and have a heart with blood in it as the origin of the parts; and

the so-called ‘entrails of earth’ (τὰ δὲ καλούμενα γῆς ἔντερα), in which comes into being the body of

the eel, have the nature of a grub (σκώληκος ἔχει φύσιν). Hence one might suppose, in connection

with the origin of men and quadrupeds (καὶ περὶ τῆς τῶν ἀνθρώπων καὶ τετραπόδων γενέσεως), that,

if ever they were really ‘earth-born’ as some say (εἴπερ ἐγίγνοντό ποτε γηγενεῖς ὥσπερ φασί τινες),

they came into being in one of two ways; that either it was by the formation of a grub at first (τὸ

πρῶτον) or else it was out of eggs […]. It is plain then that, if there really was any such beginning of

the generation of all animals (εἴπερ ἦν τις ἀρχὴ τῆς γενέσεως πᾶσι τοῖς ζῴοις) it is reasonable

(εὔλογον) to suppose it to have been one of these two. But it is less reasonable (ἧττον δ' ἔχει λόγον)

to suppose that it was from eggs, for we do not see (ὁρῶμεν) such generation occurring with any

animal, but we do see the other both in the blooded animals above mentioned and in the bloodless.

Such are some of the insects and such are the testaceans which we are discussing; for they do not

develop out of a part of something as do animals from eggs, but they grow like a grub.209

In this interesting passage, Aristotle discusses the belief in an original generation of living creatures.

In particular, his analysis pertains to the origin of animals that reproduce from other animals, as is

made apparent by his reference to “men and quadrupeds” – all creatures that reproduce from seed –

and by the contrast that he establishes between these creatures and others that are regularly

generated ἀπὸ τοῦ αὐτομάτου from the earth, like shellfishes, certain insects, and even some of the

blooded creatures. Here, Aristotle makes recourse to ancient and popular credence to strengthen his

own claim that spontaneous generation occurs only through the initial formation of a grub. He

regards this as a fact derived from empirical observation, and uses it thereafter to speculate on the

way in which animals might have originated if indeed there was ever a beginning in time (ποτε) for

their kind.

His discussion concerns only what it would be reasonable (εὔλογον) to suppose if such

hypotheses were true. The evidence required to establish the likelihood of what could have been the

origin (ἀρχή) of animals is, according to Aristotle, the experience of what we observe happening

209

De Gen. An. III 11, 762b 21 – 763a 10.

171

‘always or for the most part’. Even with this level of speculation, Aristotle remains dedicated to the

precept expressed in De Partibus Animalium: “one should study nature with a view to the majority

of cases (δεῖ δὲ τὴν φύσιν θεωρεῖν εἰς τὰ πολλὰ βλέποντα), for it is what happens either in every

case or for the most part that is in accordance with nature (ἢ γὰρ ἐν τῷ παντὶ ἢ τῷ ὡς ἐπὶ τὸ πολὺ τὸ

κατὰ φύσιν ἐστίν)”.210

Hence, according to Aristotle, since all animals that are generated without

seed arise at first from a formation of grubs, and since we do not see (ὁρῶμεν) any such generation

occurring from eggs, it would be more reasonable to suppose that if, as they say, men and

quadrupeds had originated from the earth, they would have come into being at first (τὸ πρῶτον)

from a larval stage, while it would be less reasonable (ἧττον δ' ἔχει λόγον) to suppose that such a

generation began with the formation of an egg.211

Some authors argue that Aristotle’s primary intent in this passage is to speculate on the

possibility of an evolution of man from lower forms of life;212

this, however, is incorrect. Instead, it

is to use such speculations to support his own ontogenetic – rather than chronological – belief in the

priority of the larval stage in the process of reproduction, a belief that is made clear by the

following remark, which he makes in the course of a discussion on the reproduction of insects:

It was observed previously that some insects are generated by copulation (τὰ μὲν ἐξ ὀχείας γίγνεται),

others spontaneously (τὰ δ' αὐτόματα), and besides this that they produce a grub, and why this is so.

For pretty much all creatures seem, in a certain way, to produce a grub at first (σχεδὸν γὰρ ἔοικε

πάντα τρόπον τινὰ σκωληκοτοκεῖν τὸ πρῶτον), since the most imperfect embryo is of such a nature

(τὸ γὰρ ἀτελέστατον κύημα τοιοῦτόν ἐστιν); and in all animals, even the viviparous and those that

lay a perfect egg, the first embryo grows in size while still undifferentiated into parts; now such is

the nature of the grub (τοιαύτη δ' ἐστὶν ἡ τοῦ σκώληκος φύσις).213

Thus, just as Aristotle is unwilling to accept the hypothesis of a generation ἀπὸ τοῦ αὐτομάτου of

‘men and quadrupeds’, he is also averse to discarding such an ancient, widespread, and common

210

De Part. An. III 2, 663b 27-29. 211

For an account of spontaneous generation from egg and its place in Ionian philosophy cfr. WEST [1994]. 212

Cfr. PECK [1963], p. 361-362; TORREY & FELIN, F. [1937], p. 5; ELDESTEIN [1944], pp. 148-150; SOLMSEN

[1958], p. 267; and OWENS [2010], p. 497. 213

De Gen. An. III 9, 758a 29-36. Cfr. De Gen. An. II 1, 733a 32 – 733b 16. The identification of the grub with the

initial stage of the embryological development is, as NEEDHAM [1931], p. 75 has pointed out, one of the three big

mistakes of Aristotle’s biology.

172

notion as absolutely false, even though it stands in stark contrast to his own views on natural

generation. This discussion, in which he challenges the belief that men and other quadrupeds

originated ἀπὸ τοῦ αὐτομάτου, epitomizes his attitude towards the search for truth, as expressed in

the following passage of the Metaphysics:

The investigation of the truth is in one way hard, in another easy. An indication of this is found in the

fact that no one is able to attain the truth adequately, while, on the other hand, no one fails entirely,

but everyone says something true about the nature of things […] It is just to be grateful not only to

those whose opinions we may share, but also to those who have expressed more superficial views;

for these too have contributed something to the search of truth, namely, they handed down for us the

habit of speculation.214

Two positive outcomes result from the confrontation between Aristotle’s own opinion about natural

generation and the views of those who claim that animals that are now generated from seed were

first (τὸ πρῶτον) generated without seed: first, Aristotle helps what he believes to be an incorrect

hypothesis to accord better with the biological facts as he knows them, and hence, he turns

something patently impossible – original generation of all living creatures from eggs – to something

worthy of consideration no matter how unlikely it may be – the original generation of all living

creatures from grubs; second, once rescued from its impossible formulation and made worthy of

scientific speculation, Aristotle proceeds to discover in it ‘something true about the nature of

things’, namely, that ‘all creatures seem, in a certain way, to produce a grub at first (σχεδὸν γὰρ

ἔοικε πάντα τρόπον τινὰ σκωληκοτοκεῖν τὸ πρῶτον)’.

What is at stake in this discussion is what counts as a proper scientific consideration of the

origins of life. Aristotle believes that to study the origin of life scientifically is to study the

embryological development of living creatures, and spontaneous generation plays a primary role in

such a study.215

By contrast, he finds that many of his predecessors provide an account of the origin

of living beings that lies beyond the sphere of the regular ordering of nature, and hence leaves such

214

Metaph. α 1, 993a 30 – 993b 14. 215

Cfr. also Hist. An. V 1, 539a 1-9, in which Aristotle claims that spontaneous generation is the form of generation that

ought to be studied first.

173

an origin to chance. The distinction of a sense of τὸ αὐτομάτον associated with τύχη as being the

cause of what occurs ‘neither always nor for the most part in the same way’, therefore, seems to

serve the precise purpose of excluding spontaneous generation from the domain of chance, and thus,

of distinguishing Aristotle’s own conception of natural spontaneity from the random spontaneity of

his predecessors, so as to give it a scientific foundation and rescue it from its mythological baggage.

From Aristotle’s point of view, it is not reasonable to suppose that species of animals whose

members reproduce from other members of the same kind had an origin ἀπὸ τοῦ αὐτομάτου, since

such an occurrence lies beyond the order and regularity that we observe in nature, which shows a

clear division between types of living creatures whose members are spontaneously generated and

types whose members reproduce according to their own kind. Creatures belonging to the former

type, according to Aristotle, are never observed to reproduce offspring like themselves, and this is

so for a number of ‘good reasons.’ As we have seen in De Generatione Animalium I 1, Aristotle

puts forward a logical argument to show that it is reasonable (εὔλογον) to expect that no creature

spontaneously generated will ever be capable of generating a creature of its own kind, since

spontaneous creatures are precisely those animals which are not generated from animals of the

same kind.216

However, Aristotle is also aware that a logical demonstration (ἀπόδειξις λογική) of

this sort in biology – which he also uses to explain the reason for the sterility of the mule217

– is

“too general and empty (καθόλου λίαν καὶ κενός), for all arguments not based on the appropriate

principles are empty; they only appear to be connected with the facts without being so really (ἀλλὰ

δοκοῦσιν εἶναι τῶν πραγμάτων οὐκ ὄντες).”218

The logical argument that Aristotle employs to prove that creatures spontaneously generated

cannot give birth to animals of their own kind, therefore, is far from apodictic; hence, according to

his own standard of argumentation, he cannot rule out the spontaneous generation of “man and

216

Cfr. Part II, Chapter 2. 217

Cfr. De Gen. An. II 8, 747b 27 – 748a 7: “I call it ‘logical’ because the more general it is the further is it removed

from the appropriate principles (λέγω δὲ λογικὴν διὰ τοῦτο ὅτι ὅσῳ καθόλου μᾶλλον πορρωτέρω τῶν οἰκείων ἐστὶν

ἀρχῶν)”. 218

De Gen. An. II 8, 748a 7-9.

174

quadrupeds” as impossible. The argument ought to have fewer pretenses, and consequently, to be

guided by a closer familiarity with the πράγματα, and what we observe as happening always or for

the most part. However, even if it cannot be proven to be absolutely false, once the origin in time of

‘men and quadrupeds’ is confined to what is beyond the observed regular patterns of natural

generations, its consideration no longer has a proper place within the scientific discourse. This

explains why Aristotle, while deeming the origin in time of species whose members reproduce from

their own kind to be improbable and unlikely, can still contemplate and even speculate in

reasonable detail about such a possibility. He does so by reintegrating the hypothesis within the

order of what we see happening ‘always or for the most part in the same way’: since we never see

animals being spontaneously formed from eggs, but we always see them developing from grubs, if

indeed there was such a beginning in the generation of animals, it is reasonable (εὔλογον) to

suppose that it took place from a larval formation.

Similar considerations can be made for spontaneously generated creatures that exhibit

sexual dimorphism and copulate. Aristotle believes that such creatures are able to generate, but they

generate creatures of a different kind, which are neither male nor female, and hence, are not able to

generate. Such a phenomenon, too, according to Aristotle, happens according to a precise order and

regularity for which he tries to give a justification. If the new creatures, just like their parents, were

born with sexual dimorphism and were able to copulate, and hence, to give birth to other creatures

of yet a different kind, “this would go on to infinity; but nature flies from the infinite (ἡ δὲ φύσις

φεύγει τὸ ἄπειρον), for the infinite is imperfect, and nature always seeks a completion (ἡ δὲ φύσις

ἀεὶ ζητεῖ τέλος)”.219

Even in this case, Aristotle employs a principle which is too general and distant

from the appropriate principles of biology to provide a valid scientific demonstration of the

impossibility of such an occurrence.220

Ultimately, a principle such as “nature flies from the infinite

219

De Gen. An. I 1, 715b 14-6. 220

This passage lends support to LEUNISSEN [2010] position that general teleological principles, such as ‘nature does

nothing in vain’, do not play a causal role in the ultimate explanations of natural phenomena (a position defended by

LENNOX [1997]). However, in this context, the principle is clearly not used as a heuristic tool for the discovery of

175

(ἡ φύσις φεύγει τὸ ἄπειρον)” finds its justification in the observable regularity and repeatability of

the objects of experience, and therefore, in the observation of what occurs always or for the most

part. Hence, even if the argument lacks apodictic strength and leaves open the possibility of an

unlimited succession of generations of different species of living beings, the fact that such an event

defies the order that we see ‘always or for the most part in the same way’ is sufficient to regard it as

due to chance, and therefore, to exclude it from the domain of proper scientific understanding.

No spontaneously generated creature is capable of producing another creature like itself.

This is an essential characteristic of all spontaneously generated creatures, and thus, it falls within

the sphere of what in nature happens ‘always or for the most part.’ If ever a spontaneously

generated creature were to develop so as to be capable of reproducing other creatures like itself,

which would be contrary to what happens ‘always or for the most part’, then we would all (πάντες)

say that such an occurrence had happened by chance.

This distinction allows us to solve one final conundrum emerging from the literature about

Aristotle’s spontaneous generation, one which has some interesting and important ontological

implications. According to Aristotle, if ever a creature generated from the earth were to develop so

as to be capable of reproducing other creatures like itself, we would be witnessing the generation of

an entirely new species of living beings, and we would have to describe such a generation as

happening ἀπὸ τοῦ αὐτομάτου in the sense described in the Physics. Indeed, we can draw a

distinction between chance and spontaneity, as hypotheses concerning the generation of living

creatures, by saying that while the spontaneous generation of living beings is always and only a

mode of generation of individual organisms, the generation of living beings by chance is, by

contrast, a form of generation of entire species of organisms. The distinction between two senses of

τὸ αὐτομάτον, then, is essential for Aristotle so that he may differentiate between the merely

causally relevant features of spontaneously generated creatures, and hence, does not conform to her general thesis. The

purpose of this argument has been appropriately highlighted by VEGETTI [2007], who points out that the principle is

invoked to settle a problem for his theory in a satisfactory way (εὐλόγως , repeated three times in 715b 7-10).

176

apparent exception to his theory of generation, constituted by the spontaneous growth of individual

creatures without seed, and what would be a real exception to his theory of generation, namely, the

generation by chance of entire species of living beings.

As we have seen, although spontaneously generated creatures form regular kinds as much as

creatures that reproduce from seed do, they cannot be said to form eternal species, or to belong to

γένη in the significant biological sense used “in reference to continuous generation of the same

form (κατὰ γένεσιν συνεχῆ τοῦ αὐτοῦ εἴδους)”.221

Yet, unlike the generation ἀπὸ τοῦ αὐτομάτου of

single individual creatures, which never give birth to creatures like themselves, the hypothetical

generation ἀπὸ τοῦ αὐτομάτου of a creature capable of giving birth to creatures like itself would be

a case of the generation of a γένος. We should note, however, that Aristotle has conceptual

resources to differentiate what he believes to constitute proper γένη of living beings from the sort of

γένη that would proceed from a first single common ancestor. In Metaphysics 28, in fact,

Aristotle distinguishes two fundamental senses of the term ‘γένος’:

We call something a γένος, in one sense, if there is continuous generation of things which have the

same form, (ἡ γένεσις συνεχὴς τῶν τὸ εἶδος ἐχόντων τὸ αὐτό); for example when we say ‘as long as

the γένος of men lasts (ἕως ἂν ἀνθρώπων γένος ᾖ)’ we mean ‘as long as the generation of them goes

on continuously (ἕως ἂν ᾖ ἡ γένεσις συνεχὴς αὐτῶν); in another sense a γένος is that which first

brought things into being (τὸ δὲ ἀφ’ οὗ ἂν ὦσι πρώτου κινήσαντος εἰς τὸ εἶναι), for it is in this sense

that some are called ‘Hellenes’ by γένος and others ‘Ionians’, in view of the fact that the former

proceed from Hellen as their first begetter (πρώτου γεννήσαντος) and the latter from Ion.222

A few lines later, Aristotle summarizes these two senses as follows:

γένος then is used in all these ways: in reference to continuous generation of the same form (τὸ μὲν

κατὰ γένεσιν συνεχῆ τοῦ αὐτοῦ εἴδους), and in reference to the first mover which is of the same sort

as the things it moves, (τὸ δὲ κατὰ τὸ πρῶτον κινῆσαν ὁμοειδές).223

In these passages we can distinguish a ‘biological’ sense of γένος from what can arguably be

labeled a ‘historical’ sense, which refers to the series of creatures born from an original ancestor

221

Metaph. 28, 1024b 6-7. Cfr. Part I, Chapter 7. 222

Metaph. 28, 1024a 29-34. 223

Metaph. 28, 1024b 6-8.

177

(ἀπὸ πρώτου γεννήσαντος). In the zoogonies of the mythologists and Presocratic philosophers,

animals that were originally (τὸ πρῶτον) generated ἀπὸ τοῦ αὐτομάτου from the earth and then

began reproducing their own kind would be instances of these sorts of γένη. Yet, according to

Aristotle, these sorts of creatures would not, strictly speaking, be objects of a proper scientific

understanding, but rather of historical accounts, and hence, would be as vulnerable to the power of

τύχη as are the historical actions of human beings.

178

10. Conflict without Contradiction

Ever since Balme’s study of spontaneous generation in Aristotle’s biology, prominent scholars have

noted a conflict in Aristotle’s treatment of τὸ αὐτόματον. This conflict has traditionally been framed

as a clash between a ‘theoretical’ account of spontaneity, allegedly implied by Physics B 4-6 and

endorsed in Metaphysics Z 7-9, and a ‘biological’ account, presented, most notably, in Historia

Animalium and De Generatione Animalium.

According to proponents of this view, Aristotle’s ‘theoretical’ account of spontaneity

commits Aristotle to a theory of ‘random spontaneous generation’ – a belief in the exceptional

generation, without seed, of organisms belonging to species whose members for the most part come

to be from seed. In support of their position, scholars generally point out that in Aristotle’s more

‘speculative’ and ‘philosophical’ works, τὸ αὐτόματον is characterized as an accidental cause

(αἴτιον κατὰ συμβεβηκός),224

and that the defining feature of what comes to be by virtue of an

accidental cause is that it comes to be ‘randomly’225

and ‘neither always nor for the most part’.226

By contrast, they state that Aristotle’s biological practice commits him to a theory of ‘regular

spontaneous generation’ – a belief in the regular generation, without seed, of organisms belonging

to species whose members come to be always without seed. They cite as an example Aristotle’s

zoological treatises, in which creatures that are said to be generated ἀπὸ τοῦ αὐτομάτου, come to be

with great frequency, regularity, and causal uniformity, and in this respect, they are completely

indistinguishable from creatures that come to be from seed.

Traditionally there have been two major ways of dealing with the apparent conflict. A first

approach has been to reformulate the definition of the alleged ‘theoretical’ account of spontaneity in

224

Phys. B 5, 196b 23; 197a 5-6, 12-14, and 33; B 6, 198a 6-7; Metaph. E 2, 1026b 31-33; 1027a 7-8 and 26; Metaph.

30, 1025a 14-15; Metaph. K 8, 1065a 1-3, 28, 30, and 34. 225

Phys. B 4, 196a 22; B 5, 197a 22; Metaph. E 2, 1027a 17; Metaph. 30, 1025a 25; Metaph. K 8, 1064b 36; cfr. also

De Caelo B 5, 287b 24-25 and B 8, 289b 25-27. 226

Phys. B 5, 196b 12-13, 20, and 196b 36 – 197a 1; 197a 20, and 34-5; B 8, 198b 36; 199b 24-24; cfr. also De Gen. et

Corr. II 6, 333b 6-7; De Caelo A 12, 283a 32 – 283b 1; Eth. Eud. VII 14, 1247a 31-33; Rhet. I 10, 1396a 32-34.

179

the Physics so as to deny the existence of an actual conflict with the ‘biological’ account. Thus, for

example, Johnson has argued that the Physics’ criterion according to which outcomes resulting ἀπὸ

τοῦ αὐτομάτου come to be ‘neither always not for the most part’ ought to be interpreted as saying

that species whose members come to be spontaneously are rare.227

Depew and Quevedo, on the

other hand, have claimed that exceptionality, rarity, or irregularity are not essential characters of

accidental causes.228

Lennox, for his part, has claimed that the crucial implication of accidental

causation is the absence of causal uniformity, so that, strictly speaking, the essential character of

what occurs ἀπὸ τοῦ αὐτομάτου is that is occurs ‘neither always nor for the most part in the same

way’.

Each of these positions, however, poses serious problems. Johnson’s proposal, as Balme had

already demonstrated, uses an equivocal sense of the expression ‘neither always nor for the most

part,’ which is not the relevant sense used in the Physics.229

Depew and Quevedo’s proposal is not

textually defensible, as Aristotle consistently explains that what occurs ἀπὸ τοῦ αὐτομάτου happens

‘neither always nor for the most part’ because it is due to an accidental cause.230

Finally, although

Lennox’ analysis does offer important insight into the account of τὸ αὐτόματον in the Physics, it

does not agree with Aristotle’s account of spontaneous generation, as spontaneously generated

creatures do come to be always in the same way, that is, for the same causes.231

The second approach to this problem, proposed by Balme and more recently endorsed by

Dudley, is to explain the apparent conflict by appealing to developmental hypotheses, which

involve mapping the ‘theoretical’ and the ‘biological’ accounts of spontaneity into distinct moments

of Aristotle’s intellectual development.232

On Balme’s view, in the earliest stage of his

philosophical career, when Aristotle was mainly preoccupied by metaphysical concerns and was

227

JOHNSON [2012], pp. 117-118; cfr. also MATTHEN [2009], p. 342. 228

DEPEW [2010], pp. 289-290; QUEVEDO [1989], pp. 322-324. 229

Cfr. Part I, Chapter 3. 230

Cfr. Part I, Chapter 4. 231

Cfr. Part I, Chapter 6. 232

For a general account of the state of the art concerning developmental hypotheses of Aristotle’s thought, cfr. WIANS

[1996]. For a detailed account of Balme’s developmental hypothesis, cfr. LENNOX [1996].

180

still partly attached to a mythical interpretation of nature, Aristotle believed in the exceptional

generation ἀπὸ ταὐτομάτου of the same animals that are naturally generated from seed. Such a

belief, according to Balme, finds its origin in a purely speculative account of nature, one that is not

dependent on factual observations, and is mainly grounded on abstract logical analysis and popular

beliefs.233

In the middle or transitional phase, Aristotle turned to the world of experience in order to

find evidence of his speculative constructions. As a result of his factual observations, Aristotle felt

compelled to abandon his original theory of spontaneity, and instead made a clear distinction

between those animals which are always generated ἀπὸ ταὐτομάτου and the rest, which never

are.234

Although he discarded his primitive theory, Balme believed that during this transitional

phase, Aristotle nonetheless organized all new discoveries under his basic metaphysical principles

of form and matter. Finally, in the last stage of his intellectual development, Aristotle completely

emancipated his account of spontaneity from its metaphysical legacy, and began to provide a

“simple and still more materialistic”235

account of the generation of living beings ἀπὸ ταὐτομάτου.

In Balme’s opinion, the history of Aristotle’s intellectual development shows the growth of a

genuine scientific spirit, ready to reject his own theories when they are confronted by recalcitrant

data.

Accordingly, Balme believes that we can order the different treatises in which Aristotle

speaks of spontaneous generation according to this genetic order. Hence, the Physics and the

Metaphysics, with their purely theoretical abstract speculations about the workings of nature, would

belong to the earlier stages of Aristotle’s career; the De Generatione Animalium, which abandons

the theory of random spontaneous generation, yet remains influenced by concepts elaborated upon

in the Physics and the Metaphysics – the theory of substance, the analysis of form an matter, and the

doctrine of the four causes – would belong to the transitional period of Aristotle’s career, when he

233

Cfr. BALME [1962], p. 93. 234

See, for instance, BOSTOCK [2006], p. 75: “The theory of spontaneous generation was one which he felt had to be

accepted, in the light of what he took to be the observed facts about some peculiar creatures such as shellfish.” 235

Cfr. BALME [1962], p. 99 and 101-102.

181

engaged in more empirical research, but was still attached to metaphysical constructions; finally,

the Historia Animalium, which abandons all metaphysical notions in favor of a more sober and

scientific treatment of nature, would belong to the later stage of Aristotle’s career, when he was

more inclined to materialism and the investigation of the differentiae revealed by experience as an

end in itself.236

Many authors have pointed out the risks associated with developmental interpretations, such

as the one proposed by Balme.237

To begin with, there is the suspicion that these interpretations are

viciously circular: conflicting passages are often ordered according to a preconceived narrative of

Aristotle’s development, and then made to fit a particular conception of philosophical development.

In addition, it appears quite unreasonable to accept the hypothesis that the intellectual development

236

Note that Balme reads into the biological works the very signs of the three stages of intellectual development traced

by JAEGER [1923]. According to Jaeger, in the earliest phase, deeply faithful to Platonic philosophy and primarily

absorbed in religious and metaphysical concerns, Aristotle continued to be attached to “the presuppositions of the

mythical interpretation of nature, which always retained a powerful influence over the Greek mind” (p. 293). In the

second, transitional phase, Aristotle’s concerns would take a more speculative and cosmological turn, developing

general Platonic principles according to peculiar “immanent tendencies” (pp. 271 and 293.) This is the period,

according to Jaeger, during which the Physics and a large part of the Metaphysics were elaborated. The distinguishing

feature of these “strictly philosophical” works, on Jaeger’s account, is that they present a conceptual and abstract

analysis of the general principles of nature and the world. The author sees the speculative philosophy developed in these

treatises as still rooted in a Platonic framework, and believes that the most original aspect of these works lies in their

“method of applying the principle of form” to the phenomena of nature (pp. 299 and 328). During this stage of

development, Aristotle was “very little interested in the vivid and realistic exposition of detail” (p. 291); he was instead

more concerned with developing precise and logically clear “thought-constructions” and used the observation of natural

phenomena only “to confirm his conceptual constructions” (p. 291). Finally, in the last phase, Aristotle “turns to the

empirical investigation of details” (p. 322.), thus emancipating himself from Plato and his speculative philosophy.

During this period, Aristotle’s scientific talent came to full maturation; his works during this period revealed him “as

the master not so much of philosophy as of ‘history’ in the Greek sense of the word, which includes the detailed study

of nature and natural life as well as the knowledge of human events” (p. 329.) Aristotle’s intellectual maturity was thus

marked by a “suppression of speculation in favor of factual research, (p. 387.), and his investigation during these years

explored the world of experience, not so as to confirm his metaphysical conceptions, but as a way to contemplate the

individual as an end in itself. This is the phase in Aristotle’s development when he organized his proper ‘scientific

works’, which Jaeger lists as including the whole of Aristotle’s biological writings – from the three major zoological

treatises to the collection of particular physiological investigations. Note, however, that Balme disagrees with Jaeger on

two counts. First, he rejects the overall chronology, which Jaeger assigns to Aristotle’s works: while he agrees that the

writing of the Physics and the Metaphysics can be traced as far back as Aristotle’s years in the Academy, he also has

reason to believe, unlike Jaeger, that the Historia Animalium was not written during his years at the Lyceum, that is,

during Aristotle’s latest years of activity, but rather during the ‘middle’ period of Assos and Lesbos. Second, Balme

develops his own hypothesis regarding the chronology of the zoological works in particular. Whereas Jaeger holds the

more traditional view that De Partibus Animalium and De Generatione Animalium ‘work upon’ the material collected

in the Historia Animalium and “inquire into the reasons of the phenomena that it contains” (p. 329), Balme instead

believes that since De Partibus Animalium and De Generatione Animalium show a clear influence of the concepts

elaborated upon in the Physics and the Metaphysics they must have been written prior to the Historia Animalium, given

that this work appears to abandon such metaphysical notions in favor of engaging in a more sober, scientific

investigation. 237

Cfr. for instance WIELAND [1962], and BERTI [19771-2004

2].

182

of a thinker would proceed in a linear and uniform way from an initial position to its polar opposite

through distinct intermediate steps; indeed, such a mechanical progression is completely at odds

with the very idea of development, as Aristotle himself conceives it.238

Finally, although

developmental interpretations have had a positive impact in showing the limitations of artificially

systematic readings of Aristotle’s thought,239

in truth, the authors of these interpretations seem

incapable of abandoning the idea that Aristotle was a systematic thinker. In the linear unfolding of

their narratives, Aristotle’s philosophical growth presents itself as a transition from system to

system – for instance, from an earlier ‘speculative’ system to a later ‘empirical’ one – each with

their own foundational principles, and characterized by an absence of internal contradictions.240

It is important to note, however, that the shortcomings of both of the above attempts to

resolve the apparent conflict are brought to light by focusing on the weakness not so much in their

opposing theses – namely, their different views on the relationship between the ‘theoretical’ and

‘biological’ accounts of spontaneity – but rather, and more significantly, in the common assumption

that underlies their opposing theses – namely, their shared belief that there is a ‘theoretical’ account

of spontaneity, elaborated in Aristotle’s speculative investigations, which is subsequently applied to

his biological studies. In other words, the most instructive aspect of these inadequate interpretations

is revealed not primarily by confronting Aristotle’s biological examples of spontaneity with his

‘theoretical’ account, but by calling into question the deeply entrenched assumption that there is a

theoretical account of spontaneity in Physics B 4-6, which Aristotle endorses and elaborates upon in

Metaphysics Z 6-9, and subsequently applies – whether consistently or not – to biological

phenomena.

238

We could say, using Aristotle’s words to describe cognition, that the development of a subject is not a transition

between opposite states, but rather a preservation and a change of the subject into itself and its own actuality (Cfr. De

An. II 5, 417b 2-16). JAEGER [1923], p. 4, claims that “it is one of those almost incomprehensible paradoxes in which

the history of human knowledge abounds, that the principle of organic development has never yet been applied to its

originator”. However, Jaeger’s linear narrative does not conform to the very principle of organic development, which is

at the core of Aristotle’s philosophy. 239

Cfr. JAEGER [1923], p. 373-374. 240

Thus GRAHAM [1987], for instance, speaks of “Aristotle’s two systems” - one grounded in ‘atomic substantialism,’

the other in ‘hylomorphic substantialism.’

183

Instead of relying on this problematic framework, which conceals Aristotle’s thought rather

than clarifies it, a better approach to interpreting Aristotle’s accounts of τὸ αὐτόματον is to gain a

careful awareness of the different problems that Aristotle discusses in these works and the different

contexts in which these discussions are framed. As we have seen, the idea that the Metaphysics

endorses the belief in what is now referred to as ‘random’ spontaneous generation’ is based more on

the assumption that there is a common account of τὸ αὐτόματον in the Physics and the Metaphysics

rather than on actual textual evidence; in fact, textual evidence reveals that the account of

spontaneity in the Metaphysics is actually consistent with and dependent upon the account in the

Historia Animalium, not the account in the Physics. Although this goes against Balme’s hypothesis,

and shows that the account of spontaneity in the Metaphysics depends on the studies presented in

Historia Animalium, and hence came after it, the main point to be drawn here is that the alleged

inconsistency between the biological works and the Metaphysics is only apparent, and therefore,

there is no need to resort to developmental explanations.

Thus, once the close connections between the account of spontaneity in the Metaphysics and

its foundation in the biological works is made clear, then it is possible to recognize that the Physics’

and the Metaphysics’ treatment of τὸ αὐτόματον bear only superficial similarities, and that these

works do not offer any unitary ‘theoretical’ account of spontaneity. Instead, they are devoted to the

analysis of different and equivocal phenomena: whereas the Metaphysics, in its constructive

approach, is based upon and concerns itself with the factual research of Aristotle’s own biology, the

Physics displays a polemical character and undertakes a dialectical examination of some aspects of

Presocratic cosmologies and zoogonies, which Aristotle rejects. The Physics and the Metaphysics

are therefore thematically different with respect to their treatment of τὸ αὐτόματον. Although, to be

sure, there are independent reasons for believing that the account of τὸ αὐτόματον in the Physics

was written before that of the Metaphysics, it is important to stress that since the main difference

between the two treatises is thematic – namely it deals with different problems and questions, not

184

with different answers to the same problem – the appeal to a developmental interpretation is, even

in this case, unnecessary.

In this way, then, we can recognize the presence of conflicting accounts of τὸ αὐτόματον in

Aristotle without accusing him of holding inconsistent beliefs. The account of generation ἀπὸ τοῦ

αὐτομάτου implied by the Physics does not actually reflect Aristotle’s view, but rather the view of

those who believe in the first generation, without seed, of organisms belonging to species whose

members subsequently reproduce from seed. And this view is indeed in conflict with Aristotle’s

beliefs – in fact, Aristotle believes that is not only in conflict with his biological observations, but

that it is also inconsistent from a purely logical standpoint.

In examining the most problematic and conflicting passages of Aristotelian philosophy, as is

the case when scrutinizing his position on spontaneity, we ought to bear in mind that Aristotle –

contrary to a long tradition of scholars who make reference to him – does not have a fixed, rigid,

and uniform philosophical terminology at his disposal. Most of his fundamental terminology comes

from common Greek usage, and inherits from common language its natural capacity to disclose the

fundamental equivocity present in the things themselves. Aristotle himself displays a deep

awareness of the processes through which the same term takes on different meanings, and develops

a highly sophisticated and rich account of how different things come to share the same name.241

The

use of equivocal language in Aristotle, therefore, reflects the net of mutual differences and

similarities present in the things themselves, and ought not to be forced into an artificial

systematization, or excluded by means of a developmental narrative, but valued as a positive aspect

of his way of philosophizing.242

The equivocal proposal to the apparent conflict advocated in this dissertation offers,

therefore, a solution which is Aristotelian in spirit: it suggests that we ought to begin by looking at

the very things designated by the term ‘τὸ αὐτόματον’, and then proceed to determine the reasons

241

Especially in Cat. 1, Metaph. , and Top. I, 15-18. 242

Cfr. OWENS [19511-1978

3], p. 130-131.

185

for their equivocity. This allows us to fill a lacuna that has affected all the major scholarship on the

subject by paying greater attention to the different areas of Greek knowledge and expertise, which

deal with phenomena that happen ἀπὸ τοῦ αὐτομάτου – mythology, cosmology, medicine, and

agriculture – and constitute the source of the problems that Aristotle considers in his different

works.

186

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