Physical Instantiation and the Propositional Attitudes

The paper addresses a standard line of criticism of the computational theory of mind, based on the claim that the notion of realizing a computational formalism is overly liberal to the point of vacuity. I argue that even for interesting and powerful cases, realization is essentially a matter of approximation and degree, and interpreting a physical device as performing a computation is always relative to our purposes and potential epistemic gains. However, while this may fatally undermine a computational explanation of conscious experience, I contend that, contra Putnam and Searle, it does not rule out the possibility of a scientifically defensible account of propositional attitude states in computational terms.