Abstract

I attempt to answer the question of what Aristotle's criteria for 'being a substance' are in the Categories. On the basis of close textual analysis, I argue that subjecthood, conceived in a certain way, is the criterion that explains why both concrete objects and substance universals must be regarded as substances. It also explains the substantial primacy of concrete objects. But subjecthood can only function as such a criterion if both the subjecthood of concrete objects and the subjecthood of substance universals can be understood as philosophically significant phenomena. By drawing on Aristotle's essentialism, I argue that such an understanding is possible: the subjecthood of substance universals cannot simply be reduced to that of primary substances. Primary and secondary substances mutually depend on each other for exercising their capacities to function as subjects. Thus, subjecthood can be regarded as a philosophically informative criterion for substancehood in the Categories