Philosophical Perspectives, 21, Philosophy of Mind, 2007
THINKING WITH MAPS
Elisabeth CampUniversity of Pennsylvania
Most of us create and use a panoply of non-sentential representationsthroughout our ordinary lives: we regularly use maps to navigate, charts to keeptrack of complex patterns of data, and diagrams to visualize logical and causalrelations among states of affairs. But philosophers typically pay little attentionto such representations, focusing almost exclusively on language instead. Inparticular, when theorizing about the mind, many philosophers assume thatthere is a very tight mapping between language and thought. Some analyzeutterances as the outer vocalizations of inner thoughts (e.g. Grice 1957, Devitt2005), while others treat thought as a form of inner speech (e.g. Sellars 1956/1997,Carruthers 2002). But even philosophers who take no stand on the relativepriority of language and thought still tend to individuate mental states in termsof the sentences we use to ascribe them. Indeed, Dummett (1993) claims thatit is constitutive of analytic philosophy that it approaches the mind by way oflanguage.
In many ways, this linguistic model is salutary. Our thoughts are oftenintimately intertwined with their linguistic expression, and public language doesprovide a comparatively tractable proxy for, and a window into, the messierrealm of thought. However, an exclusive focus on thought as it is expressed inlanguage threatens to leave other sorts of thought unexplained, or even to blindus to their possibility. In particular, many cognitive ethologists and psychologistsfind it useful to talk about humans, chimpanzees, birds, rats, and even bees asemploying cognitive maps. We need to make sense of this way of talking aboutminds as well as more familiar sentential descriptions.
In what follows, I investigate the theoretical and practical possibility ofnon-sentential thought. Ultimately, I am most interested in the contours ofdistinctively human thought: what forms does human thought take, and howdo those different forms interact? How does human thought compare withthat of other animals? In this essay, however, I focus on a narrower and morebasic theoretical question: could thought occur in maps? Many philosophers areconvinced that in some important sense, thought per se must be language-like:
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that there are constitutive features of thought which can only be explained ifwe assume that it has a sentential form. I will argue that on the contrary, thesefeatures can also be satisfied in a cartographic representational system. There aregood reasons to believe that much of our own thinking is sentential, but thesereasons depend on what we thinkon the particular sorts of contents that werepresent and reason aboutrather than on general features of thought as such.
1: Why Must Thought Be Language-Like?
The classic reason for thinking that thought must be language-like is thatonly this assumption can explain or justify the systematicity of thought. Theargument has been articulated most prominently by Jerry Fodor (e.g. Fodor 1975,1987; Fodor and Pylyshyn 1988; Fodor and McLaughlin 1990); but it has alsobeen defended by philosophers of a more rationalist, neo-Kantian orientation.In brief, the argument goes as follows:
1. There are systematic relations among the contents that a thinker canrepresent and reason about.
2. Systematic relations in content must be reflected by correlative structurein a thinkers representational and reasoning abilities.
3. Structured representational abilities require a system of representationalvehicles which are composed of recurring discrete parts combined ac-cording to systematic rules.
4. Any system of representational vehicles composed of recurring discreteparts combined according to systematic rules is a language.
Therefore: there must be a language of thought.
Ill consider the premises in turn.
Fodor takes the first premise as an empirical observation: when we examinethe minds around us, we find systematic relations among the contents that theycan represent. Thus, Fodor & Pylyshyn (1988, 39) write:
What does it mean to say that thought is systematic? Well, just as you dont findpeople who can understand the sentence John loves the girl but not the sentencethe girl loves John, so too you dont find people who can think the thought thatJohn loves the girl but cant think the thought that the girl loves John.
Gareth Evans (1982, 100) makes the same basic point in more a priori terms,about thoughts themselves:
It seems to me that there must be a sense in which thoughts are structured. Thethought that John is happy has something in common with the thought thatHarry is happy, and something in common with the thought that John is sad.
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The two states of affairs in the world, of John loving the girl and the girl lovingJohn, are systematically related in the sense that they involve the same individualsand properties: John, the girl, and the relation of loving; the only difference (albeitan important one) is who loves who. Premise 1 amounts to the claim that theabilities to think about such states of affairs cluster together: if you can think onethought about John, Harry, the girl, loving, or being happy, you can also thinkother thoughts about them, such as that Harry loves the girl or that the girl ishappy.1 Conversely, there are also systematic limitations in the contents a thinkercan represent: a thinker who cant entertain the thought that John blighted thegirl also cant think that Harry blighted the girl, that the girl blighted the cow, oranything else about blighting.
These systematic patterns among the contents a thinker can and cantrepresent are also manifested in how thinkers reason about those contents. AsFodor and Pylyshyn (1988, 46) say,
Its a logical principle that conjunctions entail their constituents . . .Correspond-ingly, its a psychological law that thoughts that P&Q tend to cause thoughtsthat P and thoughts that Q, all else being equal.
This point can be extended beyond deductive inference. Thus, for any inductivelawsay, that if all heretofore observed Fs are G, then probably all Fs are Gthere is an analogous psychological lawsay, that many thoughts of the formThis1 F is G, This2 F is G . . . , plus the thought that I havent seen any Fs thatarent G, tend to cause the thought that All Fs are G. In both cases, transitionsbetween thoughts track relations among represented contents.2
In the more rationalist tradition, Tim Crane (1992, 1467) claims thatjustifying the transitions thinkers make between thoughts requires us to recognizesystematic relations among their contents:
If we simply wanted to represent facts, then our beliefs would only need to havewhole contents. All that would matter would be whether a content was trueor false. The fact might have constituents (particulars and properties) but theywould have no reflection in the content, since (to echo Frege) they would as itwere have no role, no meaning of their own. But once we consider the role ourbeliefs play in reasoning, then it starts to become clear why their contents needconstituents. A thinker who believes that a is F , and that b is F , and that a is notb will be disposed to believe that at least two things are F . Surely the states inthis inference cannot just have unstructured contents, or we would not be ableto explain its validity.3
Here, Crane, like Evans, talks about structure instead of systematicity, butthe basic point again concerns systematic relations among contents: the reasonthat the transition from believing that a is F , b is F , and a is not b to believingthat at least two things are F is justified is that there are systematic, truth- andjustification-preserving relations in the contents of those beliefs.
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Premise 1 claims that there are systematic empirical and/or normativerelations among a thinkers abilities to think and reason with whole thoughts, invirtue of what those thoughts are about. Premise 2 claims that in order to explainthis systematicity in contents, we must assume that the thinkers representationalabilities are themselves structured, in the sense that they must be produced byinteracting constituent abilities to represent various parts of the world. Thus,the reason that the ability to think that John is happy clusters together with theability to think that Harry is happy is that both thoughts involve exercising ageneral ability to think about being happy. Likewise, the reason that a thinkerwho makes the transition from the thought that John is happy to John is not sadalso makes the transition from the thought that The girl is happy to The girl isnot sad is that she has a general ability to infer that if someone is happy, thenthey are not sad.
Fodor and Pylyshyn support this claim by appeal to explanatory parsimony.Unless we posit distinct interacting abilities to represent the objects, properties,and relations that together constitute whole states of affairs, the systematicpatterns of abilities and limitations that we observe among the whole contentsthat a thinker can represent will remain unexplained. More importantly, as therange of contents a thinker can represent increases, it becomes exponentially moreefficient to posit distinct, interacting abilities to represent parts of contents ratherthan distinct, unstructured abilities to represent entire contents. For instance,baboons clearly demonstrate an awareness of all the dominance relations intheir troops of approximately 40 animals. In principle, we could explain this bypostulating that they have memorized each of the approximately 800 dominancerelations separately. But it is much more parsimonious to assume that theyrepr