ABSTRACT
The identity theory enjoyed only a brief period of popularity amongphilosophers. Its decline was not the result of dualist counterattacks,however, but a consequence of the rise of a new conception of mind: functionalism. Functionalists were not put off by identity theorists’ commitment to materialism. Although, as we shall see, functionalism is not a materialist theory per se, functionalism can be seen as compatible with the spirit of materialism, and most functionalists regard themselves as materialists of one sort or another. Thus functionalists allow that, although immaterial substancesspirits, for instance-are conceivable, in all probability every substance is a material substance. If this is so, then every property possessed by a substance is possessed by a material substance. Does this imply that every property is a material property? Are mental properties a species of material property? The issues here are murky. We shall explore them in the sections that follow.
