It is now nearly axiomatic among Platonic scholars that the Timaeus and its unfinished sequel the Critias belong to the last stage of Plato's writings. The Laws is generally held to be wholly or partly a later production. So, by many, is the Philebus, but that is all. Perhaps the privileged status of the Timaeus in the Middle Ages helped to fix the conviction that it embodies Plato's maturest theories.

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.