Externalism about the mind holds that the explanation of our representational capacities requires appeal to mental states that are individuated by reference to features of the environment. Externalists claim that ‘narrow’ taxonomies cannot account for important features of psychological explanation. I argue that this claim is false, and offer a general argument for preferring narrow taxonomies in psychology.

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. (shrink)

The property of being the implementation of a computational structure has been argued to be vacuously instantiated. This claim provides the basis for most antirealist arguments in the field of the philosophy of computation. Standard manoeuvres for combating these antirealist arguments treat the problem as endogenous to computational theories. The contrastive analysis of computational and other mathematical representations put forward here reveals that the problem should instead be treated within the more general framework of the Newman problem in structuralist accounts (...) of mathematical representation. It is argued that purely structuralist and purely functionalist accounts of implementation are inadequate to tackle the problem. An extensive evaluation of semantic accounts is provided, arguing that semantic properties are, unlike structural and functional ones, suitable to restrict the intended domain of implementation of computational properties in such a way as to block the Newman problem. The semantic hypothesis is defended from a number of recent objections. (shrink)