After briefly discussing the relevance of the notions computation and implementation for cognitive science, I summarize some of the problems that have been found in their most common interpretations. In particular, I argue that standard notions of computation together with a state-to-state correspondence view of implementation cannot overcome difficulties posed by Putnam's Realization Theorem and that, therefore, a different approach to implementation is required. The notion realization of a function, developed out of physical theories, is then introduced as a replacement (...) for the notional pair computation-implementation. After gradual refinement, taking practical constraints into account, this notion gives rise to the notion digital system which singles out physical systems that could be actually used, and possibly even built. (shrink)

In much of his writing in the philosophy of mind, John Searle has been highly critical of what N. Block refers to as ‘The Computer Model of the Mind’ — the approach that treats the mind as a symbol-manipulating device akin in spirit, if not detail, to the modem computer. Searle refers to this philosophical approach as ‘cognitivism.’ The extent of his skepticism and animus toward the computer model of the mind is plainly apparent in the following quotation from Searle: (...) ‘I used to believe that as a causal account, the cognitivist's theory was at least false, but I am now having difficulty formulating a version of it that is coherent even to the point where it could be an empirical thesis at all’. In what follows, I shall attempt to show that this charge of incoherence is unfounded. (shrink)