(Εὐβουλίδης), of Miletus, a philosopher who belonged to the Megaric school. It is not stated whether he was the immediate or a later successor of Eucleides (D. L. 2.108); nor is it said whether he was an elder or younger contemporary of Aristotle, against against whom he wrote with great bitterness. (D. L. 2.109; Athen. 8.354; Aristot. apud Euseb. Praep. Ev. 15.2. p. 792.) The statement that Demosthenes availed himself of his dialectic instruction (Plut. Vit. X Orat. p. 845; Apul. Orat. de Mag. p. 18, ed. Bip.; Phot. Bibl. Cod. 265, p. 493, ed. Bekk.) is alluded to also in a fragment of an anonymous comic poet. (ap. D. L. 2.108.) There is no mention of his having written any works, but he is said to have invented the forms of several of the most celebrated false and captious syllogisms (Diog. Laert. l. e.), some of which, however, such as the διαλανθάνιον and the κερατίνης, were ascribed by others to the later Diodorus Cronus (D. L. 1.111), and several of them are alluded to by Aristotle and even by Plato. Thus the ἐγκεκαλυμμένος, διαλανθάνων or Ἠλέκτρα, which are different names for one and the same form of syllogism, as well as the ψευδόμενος and κερατίνης, occur in Aristotle (El. Soph. 24, 25, 22), and partially also in Plato (Euthyd. p. 276, comp. Theaetet. pp. 165, 175.) We cannot indeed ascertain what motives Eubulides and other Megarics had in forming such syllogisms, nor in what form they were dressed up, on account of the scantiness of our information upon this portion of the history of Greek philosophy; but we may suppose, with the highest degree of probability, that they were directed especially against the sensualistic and hypothetical proceedings of the Stoics, and partly also against the definitions of Aristotle and the Platonists, and that they were intended to establish the Megaric doctrine of the simplicity of existence, which could be arrived at only by direct thought. (H. Ritter, Ueber die Megar. Schule, in Niebuhr and Brandis' Rhein. Mus. ii. p. 295, &c.; Brandis, Gesch. der Griech. Röm. Philos. i. p. 122, &c.) Apollonius Cronus, the teacher of Diodorus Cronus, and the historian Euphantus, are mentioned as pupils of Eubulides.