Ontological Priority and Grounding in Aristotle’s Categories

In the Categories, Aristotle intends to ascribe to particular substances ontological priority over all other things, but it is far from obvious what notion of priority would make this plausible. This question is the focus of my paper. I will examine what has been the standard account of his notion of ontological priority—the “modal-existential” account—and the problems it entails, as well as some scholarly alternatives to it. I will defend my own alternative account—the “explanatory-existential” account—which addresses the problems that arise for other proposed accounts, and will make plausible Aristotle’s claim that particular substances have priority over all other things. I will argue that he puts forth this notion of priority in Categories 12, and that it bears a similarity to the notion of grounding as discussed in contemporary metaphysics.