Abstract

The aim of this paper is to argue that there are categorical properties as well as causal powers, and that the world would not exist as we know it without them. For categorical properties are needed to define the powers—to locate them, and to specify their laws of action. These categorical properties, I shall argue, are not dispositional. For their identities do not depend on what they dispose their bearers to do. They are, as Alexander Bird would say, ’quiddities’. But there is nothing wrong with quiddities. And, in the second half of this paper, I shall defend the thesis that all categorical properties are quiddities.