Abstract

Saul Kripke’s refutation of functionalism, unlike any previous attempts at a refutation, is a corollary of his work in Wittgenstein: On Rules and Private Language; in particular, it is a corollary of the arguments against dispositionalist (and extended dispositionalist) solutions to the meaning normativity paradox. Kripke’s attack is, as he acknowledges, the weakest possible, since it focuses on what many take to be the strongest aspect of functionalism: that a physical computing machine embodies the abstract diagrams of a mathematical automaton. However, any physical computing machine imperfectly realizes those abstract diagrams, since physical machines may either break down or malfunction. Indeed, that they do so is something we know only if we assume that the physical computing machine computes the function that we take it to compute. If it does not compute that function, then what we take to be a breakdown might, in fact, be part of its normal conditions of operation. That is, it might be computing a different function and not undergoing a breakdown of any sort at all. Unless we idealize its behavior, it might compute any function at all. But how we idealize its behavior depends upon what function we take it to compute. In the absence of idealizing its behavior, we don’t know what function it computes. But we can only idealize its behavior if we already know what function it computes.