Abstract

Is the specific intentional character of a thought entirely fixed by states of the thinker's body and brain? Is it entirely fixed by what he can see of his own thought with his mind's eye? A study of the sciences of thought suggests not. ;Individualism, the view that a person's intentional mental states are fixed by his physical, functional, and phenomenal states, is implicit in most modern and contemporary philosophical accounts of the mind, from Descartes to Jerry Fodor. But Putnam, Burge, and others have argued that a person's normal environment has a broadly conceptual bearing on the nature of his thought. If the natural or social surroundings of imagined replicas differ in certain ways, their obliquely specifiable thought contents contents will also differ. ;I discuss the claim, made by Stich, Dennett, and Fodor, that if we are to have a science of thought, the states it attributes must supervene on physical states of the subject's body. The burden of the dissertation is that each of several quite respectable cognitive-scientific theories attributes mental states whose non-individualistic character is deeply rooted in the theory's methodology and structure. This is argued in detail with respect to three pieces of work in cognitive psychology: Marr's computational theory of vision, Winograd's artificial intelligence program SHRDLU, and the account of object concepts as structured by similarity to a prototype. ;Each theory, I argue, uses intentional language broadly continuous with ordinary mentalistic description, and is therefore prima facie non-individualistic. Moreover, each theory presupposes a substantial conception of the success or failure of mental states, and aims at explaining how this success or failure comes about. This requires typing psychological states by reference to "externally imposed" norms of proper application, hence by reference to the actual natures of things in the world that subjects normally interact with. The argument involves excursions into such questions as whether psychological processes are syntactic, and whether our object concepts have "fuzzy" extensions