Phenomenal Concepts, Direct Reference, and the Problem of Double Aspect.

This article critically examines synthetic physicalism—the view that mental concepts are distinct from physical concepts while mental properties are identical to physical properties—focusing on how it accounts for phenomenal concepts, which directly refer to phenomenal properties. It evaluates two main versions of synthetic physicalism: the demonstrative approach, which treats phenomenal concepts as pure demonstratives lacking modes of presentation, and the constitutive approach, which holds that phenomenal properties constitute the modes of presentation of phenomenal concepts. The article argues that the demonstrative approach fails to accommodate essential phenomenal modes of presentation, as illustrated by cases like visual agnosia, while the constitutive approach leads to the problematic conclusion that phenomenal and physical concepts share identical modes of presentation, undermining their conceptual distinctness. Since these two approaches exhaust the conceptual space for direct reference, the article concludes that synthetic physicalism cannot satisfactorily resolve the "problem of double aspect," whereby the mental-physical conceptual distinction seems to imply a form of property dualism.