 The last name on list of ancient interpreters of the Categories is that of Ariston of Alexandria. From Cicero (Lucullus §§ 11–12), we learn that Ariston was among the learned men who attended the conversations that took place in Alexandria in 87 BCE between Heraclitus of Tyrus, a former student of Clitomachus and Philo of Larissa, and Antiochus of Ascalon. Cicero depicts Ariston as a pupil of Antiochus. That Ariston was a pupil of Antiochus is confirmed by the Index Academicorum, a history of the Academy written by Philodemus in the 1st century BCE. There, we are told that Antiochus “took over &lt;the Academy&gt;” (XXXIV 34 Dorandi). A list of his students is also given. The list includes the names of Aristus, Antiochus’ brother; Ariston and Dio of Alexandria; and Cratippus of Pergamum (XXXV 1–6 Dorandi). What immediately follows is extremely interesting: “Ariston of Alexandria and Cratippus of Pegamum deserted the Academy and turned Peripatetic” (XXXV 10–16 Dorandi). We are not told the reasons for their defection to Peripatetic philosophy. In the case of Ariston it is also difficult to see what this defection really involved. From the information in our possession we can only say that he wrote about the Categories. But there is no evidence that Ariston wrote in the form of a commentary. His case is significantly different from that of Andronicus and Boethus. Andronicus and Boethus made an attempt to organise, clarify, and indeed defend, the philosophy of Aristotle. This does not seem to apply to Ariston. His name is never related to those of Andronicus and Boethus. In addition, there is no evidence that Ariston was aware of the existence of Andronicus and Boethus, or that he was influenced by their works or their activity as interpreters of Aristotle. That the edition of Andronicus played a role in the conversion of Ariston to the philosophy of Aristotle is merely a conjecture.