In defence of the identity theory mark I

PREAMBLE In many philosophy of mind texts the Australian version of the mind–brain identity theory, the version that affirms type–type identities between mental states and brain states, is portrayed as the Hindenburg of modern materialist theories of mind – an interesting idea that went down in flames. Those with identity theory predilections are advised to move to a token–token identity theory dressed in functionalist clothes (of varying hues, depending on the source of the advice). I think this is a mistake. This essay says why. This essay is not a full-blown defence of the Australian version of the identity theory. It is a defence of the view that it is the version of choice for those who favour some version or other of functionalism. Two main reasons are offered for holding that the original version of the identity theory fails. First, the famous multiple realizability of the mental tells us, it is argued, that mental types cannot be identified with brain types. Second, even if this problem can somehow be overcome, the type–type version cannot give a satisfactory account of the causal role of mental properties – an embarrassing result, given that one of the main reasons offered in support of the theory in the first place is the need to account for the causal role of the mental.