We discuss Aristotle's "Categories" as an answer to Plato's One-over-Many argument. For Plato, F-ness is something "over against" particular F things; to predicate "F" of these things is to assert that they all stand in a certain relation to F-ness. Aristotle answers that predication is classification; and there being a classification of a certain sort is a fact correlative with there being things classifiable in the way the classification in question would classify them.