1 Aristotle, Connectionism, And the Morally Excellent Brain

11/27/2015 20th WCP: Aristotle, Connectionism, and the Morally Excellent Brain

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Philosophy and Cognitive Science

Aristotle, Connectionism, and the Morally Excellent BrainDavid DeMossPacific University

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ABSTRACT: Can a mass of networked neurons produce moral humanagents? I shall argue that it can; a brain can be morally excellent. Aconnectionist account of how the brain works can explain how a person mightbe morally excellent in Aristotle's sense of the term. According toconnectionism, the brain is a maze of interconnections trained to recognize andrespond to patterns of stimulation. According to Aristotle, a morally excellenthuman is a practically wise person trained in good habits. What an Aristoteliantheory of ethics and a connectionist theory of mind have in common is theassumption that the successful mind/brain has the disposition to behaveappropriately in appropriate circumstances. According to Aristotle, the goodperson knows the right end, desires and chooses to pursue it, and recognizesthe right means to it. Thus the good person's brain must be able to form certainmoral concepts, develop appropriate behavioral dispositions, and learnpractical reasoning skills. I shall argue that this collection of the brain'scognitive capacities is best accounted for by a connectionist theory of themind/brain. The human condition is both material and moral; we are braincontrolled bodies with ethical values. My essay seeks to understand therelationship between our brains and our values, between how the brain worksand how we make moral decisions.

How can the brain be a mind, a conscious person? Recently, some philosophers haveargued that human consciousness and cognitive activity, including even our moralcognition and behavior, can best be explained using a connectionist or neural networkmodel of the brain (see Churchland 1995; Dennett 1991 and 1996). (1) Is this right? Can amass of networked neurons produce moral human agents? I shall argue that it can; a braincan be morally excellent. A connectionist account of how the brain works can explain howa person might be morally excellent in Aristotle's sense of that term.

1. Connectionism

The brain receives input and somehow transforms it into output. How does it do it? In partbecause of the extraordinary technological feats achieved using digital processingcomputers, the brain has often been interpreted as a symbol manipulator and its cognitiveactivities as the transformation of symbols according to rules. By contrast, recent successes

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with parallel distributed processing computers have encouraged a connectionist theory ofmind which regards the brain as a pattern recognizer and its cognitive activities as thetransformation of neuronal activation patterns; however, these pattern transformations arenot rulegoverned processes, but straightforwardly causal processes in which networkedunits (neurons) excite and inhibit each other's activation level. The key to the connectionisttheory is the neural network. The networks are layered such that one set of units receivesthe input stimulation and resets its pattern of activation levels; some set of inbetween or"hidden" units receives as input the activation pattern of the first set of units; this set ofhidden units in turn resets its activation pattern and stimulates the next level of hiddenunits; this process of activation pattern transformation continues until the set of output unitsresets itself accordingly and thereby sends the signal for whatever action is appropriate.The brain, then, is like a vector transformer exchanging one pattern of stimulation foranother.

Churchland (1995) offers numerous examples of the brain's power to recognize patterns.Recognition of tastes, colors, and smells are all cases of the brain's receiving patterns ofactivation from stimulated sense organs, transforming those patterns by filtering themthrough layers of hidden units, and feeding those patterns to other neural nets to produce anappropriate output. Vectoral transformations at the level of hidden units are the key tocategorization. Such transformations at any given level are produced as each cell's degreeof activation is altered as a function of the stimulation it receives from each cell at theprevious level together with its own adjustable synaptic connection "weight." It is theadjustable weights that make learning new categories possible, for reconfigured weightsproduce a new inputoutput function.

A connectionist system learns by adjusting its weights. Changing the weights changes theactivation patterns produced at all levels, particularly the output level. Connectionistsystems have been successfully trained in this way to recognize faces, words, and evenmines on the ocean floor. In each case, the system's weights must be slightly readjustednumerous times to correct for output errors until it produces the appropriate inputoutputfunction. This method is called backpropagation as it uses a specialized computing rule(the generalized delta rule) to propagate the error measure that is calculated at the outputunits back through the network, thereby altering the weights. (2) Human brains probablydon't work exactly like this, but they are chock full of recurrent pathways in the maze ofneural connections which would make possible some analogous learning procedure. Likebrains, connectionist systems trained in this way, not only recognize the right face or rightword when they "see" it, they are also able to recognize new faces (that is, newpresentations of old faces) or new words not in the original training set, and to recognizepreviously encountered faces or words whose inputs are significantly degraded.

In other words, connectionist systems can generalize or categorize on the basis ofsimilarities. "There is a fairly clear sense," argue Bechtel and Abrahamsen, "in whichconnectionist networks are making similarity judgments: the similarity structure is implicitin the weight matrix. The weights are the means of treating similar inputs similarly." (3)And the weights, once set, determine stable patterns of activation within the local network.Perhaps concepts can be viewed as stable patterns of activation across an ensemble of unitswhich determine further processing. (4) Indeed, analysis of the weight configurations andactivation patterns of trained connectionist systems reveals that the multidimensionedspace defined by stabilized middle layer activation patterns is partitioned into categoriescentered on prototypical cases; (the prototypes are defined by taking an average of theactivation patterns produced by all relevant cases in the training set.) For example, in the



facial recognition system the hidden layer activation patterns for male and female facesdivide themselves along gender lines into two identifiable groups which cluster aroundprototypes for a male and a female face, respectively. Another connectionist system trainedto read aloud from the printed page neatly, and as a natural result of the backpropagationtraining, separates vowels from consonants in its middle layer activation space. (5)

We may say, then, that the networks in both brains and artificial connectionist systemsgeneralize concepts as they learn by reconfiguring their neuronal weights. And since

representations on hidden units result from the system's attempt toaccommodate to its environment . . . , [this] learning procedure also gives thenetwork a goal: maximizing the fit of its states to those of the environment (byminimizing error in producing outputs to inputs). Thus a teleologicalcomponent is added. As a result, the representations developed in the hiddenunits subserve goals, and so can be thought of as representing informationabout things external to the system for the system. Hence, these representationsare about the entities supplying the input. (6)

Bechtel and Abrahamsen here suggest that the activation patterns of the hidden units in atrained connectionist system are intentional states, for such representations are produced bythe system in order for the system to pursue its ends.

We may conclude that since a connectionist system is capable of having concepts relevantto the achievement of its ends, ends the system is disposed to pursue under appropriatecircumstances, then the brain, as connectionist system, has some of the abilities required ofa system capable of moral excellence. For according to Aristotle, the morally excellentperson must have some cognitive grasp of the end as well as a disposition to pursue thatend. Aristotle also insists that moral excellence involves practical wisdom, the ability torecognize what needs to be done in order to achieve one's ends in various circumstances.As we shall see, connectionist systems are also capable of matching means to ends, ofmodifying their own behavioral output relative to the demands of a perceived situation. (7)In this paragraph I have introduced the main argument of my essay, which will be furtherdeveloped in section three. However, I must first sketch some more details of Aristotle'sethical system.

2. Aristotelian Ethics

Aristotle argues that the good person is both practically wise and morally excellent. Moralexcellence is a state of character in which one desires and chooses to pursue appropriateethical ends or goals. Practical wisdom involves the rational capacity to deliberate wellabout what means are best for pursuing these ethical ends. Given experience and time,practical wisdom is teachable to the extent that practical reasoning skills are teachable.Moral excellence, however, is a matter of the formation of good habits; one must becomedisposed to pursuing ethical ends. This combination of moral character and practicalintellect are essential to ethical action, for the former makes one do the end and the latterthe means to the end.

The practically wise person excels at deliberating, calculating means to ends. Butdeliberation requires a grasp of the end as a startingpoint, what Aristotle calls an arche orfirst principle; he claims that "in practical affairs that for the sake of which [i.e., the end] isa startingpoint." (8) I have argued elsewhere that, according to Aristotle, the process



through which one may acquire such ethical ends is inductive. (9) Good deliberation alsorequires an ability to see connections between means and ends, between the particularthingstobedone and the goals to be pursued. Such means/ends connections are alsostartingpoints of a second kind, startingpoints for the induction of the end; "for theuniversals are from the particulars; of these it is necessary to have perception, and this isnous." (10) Nous, variously translated as "intuitive reason" or "comprehension" or "practicalinsight," is the capacity to perceive particular thingstobedone as a means to an end.Thus, this ability to grasp connections between means and ends, the hallmark of practicalwisdom, operates both in the process of induction to ethical ends and in the process ofdeliberation from ethical ends. (11)

So ethical ends are startingpoints derived by induction, and means/ends connections arestartingpoints seen by the perceptual insight of nous. Where E is the end and M the means,here is how these two startingpoints would function syllogistically as premises indeliberation:

1. E is what I should do. [ethical end startingpoint]

2. M is (a means to) E. [means/end startingpoint]

3. Therefore, M is what I should do. [conclusion]

This represents the logical form of deliberation, even though real agents need not thinkthings through in this formal fashion. Likewise with the induction of the ethical end, whichin form is the syllogistic reverse of the deliberation:

3. M1 (and M2, and M3, etc.) are what I should do.

2. M1 (and M2, and M3, etc.) are (means to) E.

1. Therefore, E is what I should do.

In this case, the M's in 3 are not necessarily recognized as means to an end; that recognitionis represented by statement 2, the means/end startingpoint. Statement 3 is a third kind ofstartingpoint, acquired by habit. Aristotle claims that moral excellence or virtue comesabout as a result of habit, that we become just by doing just acts; this is why the habits oneforms from training in youth make "a very great difference, or rather all the difference." (12)Thus the M's in 3 indicate the cases in the training set, for example the various commandsthat adults issue to children learning to be just. ("Give Bobby a chance to play," "Don't hither, she didn't do anything to hurt you," "You have to give his ball back, it's not yours,""You broke the window, now how do you expect to pay for it?") Although we sometimestell children why they must behave in certain ways, we often as a startingpoint simply tellthem that they must so behave and then leave it to them to induce the ends as theyaccumulate more experience. (13)

Along the way to moral excellence and practical wisdom, then, Aristotle recognizes threekinds of startingpoints, ethical ends, means/ends connections, and particular things to bedone. These three kinds are acquired, respectively, by induction, by the perceptual insightof nous, and by habit. (14) By induction one knows the end, by habit one desires (pursues)the end, and by perceptual insight (nous) one recognizes how to reach the end. If a personis to achieve moral excellence s/he must have these cognitive capacities, as must anyconnectionist system capable of moral excellence, like a human brain for instance.



3. The Psychological/Cognitive Capacities of the Morally Excellent Brain

Aristotle's account of the psychological capacities of the morally excellent person iscompatible with a connectionist theory of the mind/brain. The good person's brain must beable: to form morally relevant concepts (by induction) to recognize ethical ends; to developappropriate behavioral dispositions (by habit) to pursue ethical ends; and to learn practicalreasoning skills (by nous) to perceive the means to the ends. This collection of the brain'scognitive capacities are best accounted for by a connectionist theory of the mind/brain.

We have already seen that connectionist systems have the ability to generalize categoriesand then apply the concepts to new or modified cases. By reconfiguring its neuronalweights, my brain can learn to recognize the faces of more than fifty new students in just afew weeks time; and then, as a matter of learned habit, my brain can produce the rightname for the right face in a variety of circumstances. Stable activation patterns have beenestablished in the hidden units of my brain's neural nets. And this same training thatestablishes the habits establishes the concepts. When the "Kari Middleton" category isactivated I am disposed to produce her name; and given the complexity of the connectionistsystem in my head, I am also disposed to behave in her presence in ways bound up with mycategories of "female" and "student." If connectionism provides a plausible account of thisbrain training, and it does, then it may also account for my tendency to respect my studentsas persons and to treat them fairly. Parents and teachers insisted that I share my toys, that Ilisten while others are talking, that I not deceive others to gain an advantage, etc. From thistraining set, Aristotle would argue, I have generalized a concept of fairness or justice, andhave become disposed by habit to pursue the goal of behaving fairly and justly.Connectionism provides a likely account of the brain's role in this Aristotelian process. Themorally excellent brain recognizes (by induction) and pursues (by habit) ethical ends.Given the proper stimulation, learned vector patterns are activated in the hidden units of thebrain, and this activation is at once both a recognition of the goal and a disposition topursue it.

Aristotle also insists that moral excellence involves practical wisdom, the ability torecognize (by nous) what needs to be done in order to achieve one's ethical ends. Thisability requires the identification of both an appropriate categorization of the perceivedsituation and an appropriate action to be taken to meet the demands of the situation. As wehave just seen, for a connectionist system to categorize a situation, even a new one, is todispose itself to pursue a certain goal and to produce a certain output. In the case of arelatively simple singletask connectionist system like the facerecognizer, this may well bethe end of the story. Its end goal is to identify faces; categorizing a face as Bill's facesalready disposes it to pursue this end by the means of identifying the presently perceivedface as Bill's face; but since the particular manner of its output (words on a screen perhaps)is presumably hardwired and arbitrary, honing its means to any further detail is beyond itsken. However, for a system requiring motor skills for interaction with the environment, thestory may continue. Initially categorizing the situation might not be sufficient for triggeringthe appropriate means for achieving the goal.

Suppose you are a crab in search of a tidbit. You categorize your present situation as "foodfor me off to the right," that is, you are stimulated into a neural activation pattern thatdisposes you toward the goal of grabbing and ingesting the food. But you aren't hardwiredto display your categorization on a monitor screen, nor would you find that outputfulfilling. You need to actually grab the food and get it in your mouth before it movesaway. Thus you need a welltimed transformation of sensory vectors into motor vectors, a



transformation likely to involve a variety of interacting neural nets generating complexsequences of activation vectors. (15) Only in this way may your goal be achieved by movingyour arms and pincers in the right way at the right time. (16) This sort of matching of meansto ends, this sensorimotor coordination, is, according to Paul Churchland, "whereintelligence begins: in the brain's capacity for executing principled sensorimotortransforms. . . . [and] this knowhow is embodied in the personal configuration of thebrain's synaptic weights." (17) Aristotle would call such intelligence or knowhow, whenapplied in the realm of ethics, practical wisdom, the ability to recognize and do what needsto be done in order to achieve one's ends, in the right manner at the right time.

You are no longer a crab in search of a tidbit, but an undergraduate in search of lunch.Waiting in line at the lunch counter, you categorize your present situation as "hamsandwich for me off to the right." You are stimulated into a neural activation pattern thatdisposes you toward the goal of grabbing and ingesting the sandwich. But you have beenreading about animal rights issues in your ethics course. You hesitate as another category isactivated, "suffering person nearby." Activation of this category normally disposes youtoward alleviating the suffering of others. Pigs aren't persons, but they are similar in someways. "Suffering pigs" begins to occupy a point in vector space uncomfortably near"suffering persons." You find yourself stimulated into a neural activation pattern thatdisposes you to not grab the sandwich. To thus extend a category or prototype in one'smoral deliberations is to insightfully perceive another means to one's ethical ends. (18) Theundergraduate's imaginative connection between suffering pigs and suffering persons is,among other things, the perceptive insight that certain particular acts are means topreviously established ends; refusing to eat pigs is a means to alleviating suffering. Thisinsight into means/end connections is the work of nous, to use Aristotle's term; and nous isthe mark of practical wisdom. (19)

Thus the connectionist brain does have the cognitive capacities to achieve moral excellenceand practical wisdom, in Aristotle's sense of those terms. It can know the right end byinduction, desire the right end by habit, and perceive the right means by nous. In the end,what makes a brain morally excellent and practically wise is the proper setting of itsneuronal weights to establish hidden layer activation patterns capable of transformingsimilar inputs into similar outputs. That may sound too mechanical. But by filling in themechanical details, one sees that some of the capacities of the connectionist brainmachinery are just those capacities required for the production of ethical behavior. Thus thehuman condition is both material and moral; we are braincontrolled bodies with ethicalvalues.

Notes(1) Whereas Paul Churchland insists on accounting for the cognitive capacities and evenconsciousness of the human brain by appealing directly to the amazing features ofconnectionist systems, Daniel Dennett argues that "even if we succeeded in explaining[complex cognitive] processes at the level of synapses or bundles of neurons, we would bemystified about other aspects of what must be happening" (1991, p.193). For example,what is unique about human cognition and consciousness is our ability to store and thenmanipulate concepts or ideas as needed in a serial fashion; hence human brains must havethe capacity to rerepresent the representations that occur in their neural networks. ThusDennett argues that "[c]onscious human minds are moreorless serial virtual machinesimplemented . . . on the parallel [connectionist] hardware that evolution has provided for



us" (1991, p.218). This virtual machinery involves the "improvements we install in ourbrains when we learn our languages, [which] permit us to review, recall, rehearse, redesignour own activities, turning our brains into echo chambers of sorts, in which otherwiseevanescent processes can hang around and become objects in their own right. . . . [W]ithouta natural language [a creature] has no talent for wresting concepts from their connectionistnests and manipulating them" (1996, pp.155, 159). Churchland responds that Dennett'svirtual serial machine is an unnecessary level of explanation: "The fact is, there exists adifferent way, a much more natural and effective way, of accounting for the wellbehavedtemporal unfolding of consciousness, and it has nothing essential to do with serialcomputers or languagelike processing. The alternative lies in the dynamical behavior ofreal (not virtual) recurrent networks, with their dramatic ability to generate complexrepresentations with a continuously unfolding temporal dimension" (p.267).

Both Churchland and Dennett agree that the hardware of the brain is connectionist. Dennettbelieves that a virtual metamachine must be running on top of that connectionist hardwareto account for the sophisticated cognitive activity of conscious humans; Churchlandbelieves that features of the connectionist system alone are sufficient. Is Dennett positingan unnecessary "higher" level of explanation? Or is he developing useful ways ofdescribing the intense complexity of the connectionist system that is the human brain? Iwill be following Churchland's lead in this essay, although Dennett's alternative wouldprovide an important contrast.

(2) For a sophisticated description of this learning procedure see chapter three of Bechteland Abrahamsen 1991. For a much simpler version see Churchland 1995, pp.4245.

(3) Bechtel and Abrahamsen 1991, p.121.


(5) See Churchland 1995, chs. 34.


(7) Matching means to ends is in part a problem of sensorimotor coordination. Accordingto Churchland (1995), networked systems can solve this problem.

The problem is how to produce behavior that is appropriate or intelligentrelative to a perceived situation. . . . If the external environment is representedin the brain with highdimensional coding vectors; and if the brain's "intended"bodily behavior is represented in its motor nerves with highdimensionalcoding vectors; then what intelligence requires is some appropriate or welltuned transformation of sensory vectors into motor vectors! What sort ofmechanism might perform such a task? We already know the answer: a multilayered neural network, with a wellconfigured matrix of synaptic connectionweights. (p.93)

(8) Nicomachean Ethics 1151a16. Translations are mine.

(9) DeMoss 1990, "Acquiring Ethical Ends." My account of Aristotelian ethics in thepresent essay is supported by arguments presented in DeMoss 1990 which involve detailedanalysis of passages from Nicomachean Ethics.



(10) Nicomachean Ethics 1143b45.

(11) Aristotle warns, "Let it not escape our notice that the arguments from the startingpoints and those to the staringpoints differ" (Nicomachean Ethics 1095a3032).

(12) Nicomachean Ethics 1103b2425.

(13) Aristotle often stresses the necessity of training in good habits as a foundation formoral growth; he writes, "Wherefore the one who will be listening competently to whatconcerns good and just things and in general the science of politics must have been welltrained in his habits. For the startingpoint is the that, and if this should be sufficientlyapparent, one will not need in addition the reason why" (Nicomachean Ethics 1095b68).(See also 1098a33b3.)

(14) It is not surprising, then, that Aristotle claims that "some [startingpoints] are seen byinduction, some by perception, and some by a certain acquisition by habit, and others alsoin other ways" (Nicomachean Ethics 1098b34).

(15) See Churchland 1995, chapter 5, "Recurrent Networks: The Conquest of Time."

(16) One is reminded here of Aristotle's warning that there are many ways to go wrong inthe choice of means. One must do the right thing in the right way at the right time. (SeeNicomachean Ethics 1142b1628.)

(17) Churchland 1995, p.95.

(18) In his book, Moral Imagination: Implications of Cognitive Science for Ethics (1993),Mark Johnson explains,

A central part of our moral development will be the imaginative use ofparticular prototypes in constructing our lives. . . . Many of our moralproblems stem from questions about permissible metaphorical extensions fromthe prototype to noncentral members . . . . Our moral deliberations will beabout whether, for instance, certain 'higher' mammals ought to be understoodmetaphorically as persons, and therefore accorded certain rights. (pp.192 and195)

(19) See DeMoss 1990, pp.7273, where I discuss the nature of practical reasoning andargue that the "recognition that certain particular acts are means to an end . . . requires animaginative leap, a special kind of perception, nous."

ReferencesAristotle, Ethica Nicomachea, ed. Bywater (1894) (Oxford: Oxford University Press).

Bechtel, W. & Abrahamsen, A. (1991), Connectionism and the Mind: An Introduction toParallel Processing in Networks (Cambridge, MA: Basil Blackwell).

Churchland, Paul (1995), The Engine of Reason, the Seat of the Soul: A PhilosophicalJourney into the Brain (Cambridge, MA: MIT Press).

Churchland, Paul (1988), Matter and Consciousness: A Contemporary Introduction to the



Philosophy of Mind, revised edition (Cambridge, MA: MIT Press).

DeMoss, David (1990), "Acquiring Ethical Ends," Ancient Philosophy, 10, pp. 6379.

Dennett, Daniel (1991) Consciousness Explained (Boston, MA: Little Brown).

Johnson, Mark (1993) Moral Imagination: Implications of Cognitive Science for Ethics(Chicago: University of Chicago Press).

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1 Aristotle, Connectionism, And the Morally Excellent Brain