Substance and Independence in Aristotle

Individual substances are the ground of Aristotle’s ontology. Taking a liberal approach to existence, Aristotle accepts among existents entities in such categories other than substance as quality, quantity and relation; and, within each category, individuals and universals. As I will argue, individual substances are ontologically independent from all these other entities, while all other entities are ontologically dependent on individual substances. The association of substance with independence has a long history and several contemporary metaphysicians have pursued the connection. In this chapter, I will discuss the intersection of these notions of substance and ontological dependence in Aristotle. Ontological dependence plays a central role in Aristotle’s metaphysics of properties, as well as in his philosophy of mathematics, philosophy of mind and elsewhere. As I will note, he typically uses separation and priority terminology to refer to a notion of ontological dependence: one thing is ontologically independent from a second just in case the first is both separate from, and prior to, the second. To give just a few examples of Aristotle’s use of such terminology: in addition to the claim that individual substances are ontologically independent from universals and entities in categories other than substance, Aristotle also holds that individual properties are inseparable from that in