distinguishes between statements of this kind and those made by the characters themselves in the dialogue. The latter require special investigation and confirmation before being regarded as true. Much of the following space is occupied with Plato's references to the Sophists. The myth, which Protagoras (Prot., 320 C ff.) recounts, has been generally regarded as taken from a writing of this Sophist. Z. defends this generally accepted view against the objection of Gomperz by a number of arguments, and cites two new passages in favor of the old interpretation: Aristotle, part. an. IV, 10. 687 a 23, and Διαλέξεις ὴθικαί (c. 5, p. 551 a, Mull.). References to doctrines of Aristippos, Antisthenes, and the many others cited by Z., show, as he points out, in what intimate relationship Plato stood to the intellectual movement of his time, and what a lively interest he took, as one of the contending parties, in its scientific conflicts.
The Peripatetic philosopher, Ariston of Keos, and the Stoic of the same name, of Chios, have been much confused. In earlier times, writers followed the catalogue of the works of the Stoic (Diog. Laert, VII, 163), where a note is added: "But Panaitios and Sosikrates claim that only the letters are to be ascribed to him, the remaining works to the Peripatetic Ariston." Lately, writers have made Ariston's relationship to Bion the basis of treatment, using, however, the wrong Ariston. One learns of the Stoic best from Seneca, Epist. 94, which contains a short account of his teaching. Seneca says expressly, that this doctrine he describes belongs to Ariston 'Stoicus.' From the Peripatetic Ariston we have fragments of at least two works,—one on Old Age, and another on Characters. The last named was used by Philodemos in Bk. X of his de vitiis. This kind of writing is peculiar to the early Peripatetic school, and points conclusively to the origin of this work. Also the ὁμοιώματα Ἀρίστωνος is to be referred to the Peripatetic, although Wachsmuth, Zeller, Heinze, Hirzel, and others ascribe it to the Stoic; the content of some of the fragments, however, preclude a Stoic origin (Stob., Flor., IV, 200 Mein.; I, 263; III, 193). To the Stoic is to be referred the Protreptikos used by Seneca and Sextos; and to the Peripatetic, the writings, περὶ τῶν διὰ τύχην ὑπερηφανούντων, On Old Age, and at least partly, if not entirely, the ὁμοιώματα. The imitations of Bion are to be referred, not to the Stoic, but to the Peripatetic. Strabo mentions the Peripatetic philosopher Ariston as imitator of Bion of Borysthenes, and as a native of Julis in Keos. Comparison of the work on Old Age and the ὁμοιώματα with Bion, reveal that the former have much in common with the latter. The influence of Theophrastos is
