CATEGORICAL PRIORITY AND CATEGORICAL COLLAPSE

I explore some of the ways that assumptions about the nature of substance shape metaphysical debates about the structure of Reality. Assumptions about the priority of substance play a role in an argument for monism, are embedded in certain pluralist metaphysical treatments of laws of nature, and are central to discussions of substantivalism and relationalism. I will then argue that we should reject such assumptions and collapse the cate-gorical distinction between substance and property. A central project of contemporary metaphysics is to understand the nature of the world as a whole. The traditional way to approach this project is to develop an account of the metaphysically basic kinds, that is, of the fundamental ontological categories of the world. But in addition to giving an account of what the fundamen-tal ontological categories are, we need to give an account of how they and their members ground the overall structure of the world. This means that a fully developed fundamental ontology has a complex, interlocking structure. Part of the structure is determined by the nature and organization of the fundamental and derivative ontological categories, and part of the structure is determined by the way members of the categories are arranged and related in the world. Thus, an account of the metaphysical ground of Reality has three central elements: (i) an account of what the metaphysically ba-sic categories and the relations between them are, (ii) an account of the way members of these basic categories are combined and ar-ranged, and (iii) an account of the rules of ground, that is, an ac-count of how the metaphysically basic categories, their members and their arrangements ground the rest of Reality. I will discuss the project of understanding the nature of the world as a whole primari-ly in terms of the way metaphysically basic categories and the mem-bers of these categories are arranged so as to provide the ground fo