Online research in philosophy

One of several problems concerning the possibility of mental causation is that the causal potential of a supervenient property seems to be absorbed by its supervenience base if that base and the supervenient property are not identical. If the causal powers of the supervenient property are a proper subset of the causal powers of the supervenience base then, according to the causal individuation of properties, the supervenience base seems to do all the causal work and the supervenient property appears to be futile. Against this consequence it is possible to argue, first, that the relevant properties of causes must be in some sense proportional to the relevant properties of their effects and, second, that the principle of causal closure serving as a premise in the supervenience argument is probably false. The constraint that the relevant properties of causes should be proportional to the relevant properties of their effects together with the falsity of the closure principle leads to a restoration of the causal efficacy of supervenient properties.

The role of content in computational accounts of cognition is a matter of some controversy. An early prominent view held that the explanatory relevance of content consists in its supervenience on the the formal properties of computational states (see, e.g., Fodor 1980). For reasons that derive from the familiar Twin Earth thought experiments, it is usually thought that if content is to supervene on formal properties, it must be narrow; that is, it must not be the sort of content that determines reference and truth-conditions. An interesting alternative to this view has recently been proposed by Egan (1995). According to Egan, the explanatory role of content is such that contents must in general be broad to be explanatorily relevant. But Egan’s view involves a non-realist interpretation of content assignments. I will argue here that this non-realism about contents is undermotivated. A realist variation on her view of the explanatory role of content, however, would survive this criticism. This realist variation, I suggest, shares with the views of other commentators on Marr’s theory (e.g., Burge 1986; Shapiro 1993; forthcoming) certain commitments concerning the supervenience base of visual contents and processes. I will argue, however, that these commitments beg important questions regarding the individuation of cognitive states and processes. I conclude, contrary to Burge and Shapiro, that Marr’s theory does not favor anti-individualism.

I. the view that reasons cannot be causes. II. the view that the explanatory relevance of psychological states such as beliefs and intentions derives from their content, their explanatory role is not causal and we thus have no good reason to ascribe causal power to them. III. the idea that if the mental supervenes on the physical, then what really explains our actions is the physical properties determining our propositional attitudes, and not those attitudes themselves. IV. the thesis that since there are no laws linking (intentional) mental states to actions, those states cannot be genuine causes of action.

What we do, intentionally, depends upon the intentional contents of our thoughts. For about ten years Fodor has argued that intentional behavior causally depends upon the narrow intentional content of thoughts (not broad). His main reason is a causal powers argument—brains of individuals A and B may differ in broad content, but, if A and B are neurophysically identical, their thoughts cannot differ in causal power, despite differences in broad content. Recently Fodor (Fodor, 1991) presents a new 'modal' version of this causal powers argument. I argue that Fodor's argument (in old or new dress) is a non sequitur. It neither establishes the existence of narrow content nor the need for a content other than broad content to explain intentional behavior.

If psychology requires a taxonomy that categorizes mental states according to their causal powers, the common sense method of individuating mental states (a taxonomy by intentional content) is unacceptable because mental states can have different intentional content, but identical causal powers. This difference threatens both the vindication of belief/desire psychology and the viability of scientific theories whose posits include intentional states. To resolve this conflict, Fodor has proposed that for scientific purposes mental states should be classified by their narrow content. Such a classification is supposed to correspond to a classification by causal powers. Yet a state's narrow content is also supposed to determine its (broad) intentional content whenever that state is 'anchored' to a context. I examine the two most plausible accounts of narrow content implicit in Fodor's work, arguing that neither account can accomplish both goals.

There is a growing acceptance of the idea that the explanatory states of folk psychology do not supervene on the physical. Even Fodor (1987) seems to grant as much. He argues, however, that this cannot be true of theoretical psychology. Since theoretical psychology offers causal explanations, its explanatory states must be taxonomized in such a way as to supervene on the physical. I use this concession to invert his argument and cast doubt on the received model of folk psychological explanation as causal explanation by intentionally individuated states. This in turn undermines the central model of cognitive theory--causal explanation by representational states.

Owens (1993) argues that one cannot accept the anti-individualistic conclusions of arguments inspired by Twin Earth thought experiments and still maintain that folk psychological states causally explain behavior. Saidel (1994) has argued that Owens' argument illegitimately individuates the contents of folk psychological states widely and causal powers narrowly. He suggests that causal powers may well be wide, and that the conditions that militate in favor of wide content also militate in favor of wide causal powers; mutatis mutandis for narrow content and narrow causal powers. I argue that these suggestions are in error, and hence that Saidel's criticism is ineffective. Owens' original point is therefore likely to stand.