Abstract

Synthetic physicalism—understood as the view that while mental concepts are distinct from physical concepts, mental properties are nonetheless identical to physical properties—is the dominant type of reductive physicalism in the philosophy of mind. With a focus on phenomenal concepts, this article examines two competing versions of synthetic physicalism: the demonstrative approach and the constitutive approach, both of which attempt to cash out the common idea that phenomenal concepts directly refer to phenomenal properties. I aim to argue that the synthetic physicalist is impaled on a dilemma in addressing what I call the problem of double aspect: the mental-physical conceptual distinction seems to imply property dualism at a new level. Either she adopts the demonstrative approach or she goes for the constitutive approach, but neither option is acceptable.