Abstract
It is becoming increasingly clear that the deepest problems currently exercising philosophers of mind arise from an ill-begotten ontology, in particular, a mistaken ontology of properties. After going through some preliminaries, we identify three doctrines at the heart of this mistaken ontology: (P) For each distinct predicate, “F”, there exists one, and only one, property, F, such that, if “F” is applicable to an object a, then “F” is applicable in virtue of a’s being F. (U) Properties are universals, not particulars. (D) Every property is either categorical or dispositional, but not both. We show how these doctrines influence current philosophical thinking about the mind, suggest and defend an alternative conception of properties, and indicate how this conception provides answers to two puzzles besetting contemporary philosophy of mind: the problem of mental causation and the problem of qualia.