Abstract

In the ongoing debate, there are a set of mind-body theories sharing a certain physicalist assumption: whenever a genuine cause produces an effect, the causal efficacy of each of the nonphysical properties that participate in that process is determined by the instantiation of a well-defined set of physical properties. These theories would then insist that a nonphysical property could only be causally efficacious insofar as it is physically implemented. However, in what follows we will argue against the idea that fine-grained mental contents could be physically implemented in the way that functional properties are. Therefore, we will examine the metaphysical conditions under which the implementing mechanism of a particular instance of a functional property may be individuated, and see how genuine beliefs and desires—insofar as they track the world—cannot meet such conditions.