 The temptation to credit all ancient interpreters of the Categories with a commentary must be resisted also in the case of Eudorus of Alexandria. It is generally assumed that Eudorus flourished in the middle of the first century BCE. Simplicius is not content to enumerate Eudorus among the ancient interpreters of the Categories. He preserves nine testimonies in which Eudorus took issue with Aristotle. But no inference about the form of his literary production is possible. The only safe inference is that the study of the Categories was not confined to the school of Aristotle. In fact, Eudorus was not a Peripatetic philosopher. Simplicius refers to him as the “Academic Eudorus” (In Cat. 187.10).