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metaphysics

The Categories

κατηγορίαι

Ten basic ways of saying what something is — substance, quantity, quality, relation, and the rest of Aristotle's list.

Aristotle's Categories is his system of the ten fundamental ways that any statement can make a claim about reality. Rather than listing random properties of things, Aristotle organized predication itself—the act of saying something "is" a certain way—into distinct kinds: substance, quantity, quality, relation, action, passion, possession, condition, time, and place. This framework became foundational to Western logic because it maps onto the structure of existence itself, not merely language.

The practical power of the Categories appears when we recognize that "good" doesn't mean the same thing across different contexts. God may be good as a substance—as the very essence of goodness—while a knife is good in the category of quality, or a person good in relation to their community. By sorting predications into categories, Aristotle gave philosophers and logicians a tool to avoid confusion and clarify exactly what kind of claim is being made.

Where this idea shows up

25 Greek sources·1 Jewish-canon citation

Where to read it