Philo the Megarian, or Dialectician
Philo The Megarian, Or Dialectician was a disciple of Diodorus Cronus, and a friend of Zeno, though older than the latter, if the reading in Diogenes Laertius (7:16) is correct. In his Menexenus he mentioned the five daughters of his teacher (Clem. Alex. Strom. 4:528, ed. Potter), and disputed with him respecting the idea of the possible, and the criteria of the truth of hypothetical propositions. With reference to the first point, Philo approximated to Aristotle, as he recognised that not only what is, or will be, is possible (as Diodorus maintained), but also what is in itself conformable to the particular purpose of the object in question, as of chaff to burn (κατὰ ψιλὴν λεγόμενον ἐπιτηδειότητα; Alex. Aphrod. Nat. Qual. 1:14; comp. on the whole question Harris, in Upton's Arriani Dissertat. Epict. 2:19, ap. Schweighiuser, 2:515, etc.). Diodorus had allowed the validity of hypothetical propositions only when the antecedent clause could never lead to an untrue conclusion, whereas Philo regarded those only as false which with a correct antecedent had an incorrect conclusion (Sext. Empir. Adv. Math. 8:113, etc.; Hypotyp. 2:110; comp. Cicero, Acad. 2:47; De Fato, 6).
Both accordingly had sought for criteria for correct sequence in the members of hypothetical propositions, and each of them in a manner corresponding to what he maintained respecting the idea of the possible. Chrysippus attacked the assumption of each of them.
The Philo who is spoken of as an Athenian and a disciple of Pyrrhon, though ridiculed by Timon as a sophist, can hardly be different from Philo the dialectician (Diog. Laert. 9:67, 69). Jerome (Jov. 1) speaks of Philo the dialectician and the author of the Menexenus as the instructor of Carneades, in contradiction to chronology, perhaps in order to indicate the sceptical direction of his doctrines.