[180] Plato, Republic, vii. pp. 538 D-539. ὅταν τὸν οὕτως ἔχοντα ἐλθὸν ἐρώτημα ἔρηται, τί ἐστι τὸ καλόν, καὶ ἀποκρινάμενον ὃ τοῦ νομοθετοῦ ἤκουεν ἐξελεγχῇ ὁ λόγος, καὶ πολλάκις καὶ πολλαχῆ ἐλέγχων εἰς δόξαν καταβαλῇ ὡς τοῦτο οὐδὲν μάλλον καλὸν ἢ αἰσχρὸν, καὶ περὶ δικαίου ὡσαύτως καὶ ἀδίκου, καὶ ἃ μάλιστα ἦγεν ἐν τιμῇ, &c.
[181] Plato, Repub. vii. p. 539 B.
Accordingly, we must not admit (says Plato) either young men, or men of ordinary untrained minds, to dialectic debate. We must admit none but mature persons, of sedate disposition, properly prepared: who will employ it not for mere disputation, but for the investigation of truth.[182]
[182] Plato, Repub. vii. p. 539 D.
Contradiction with the spirit of other dialogues — Parmenidês, &c.
Now the doctrine thus proclaimed, with the grounds upon which it rests — That dialectic debate is unsuitable and prejudicial to young men — distinctly contradict both the principles laid down by himself elsewhere, and the frequent indications of his own dialogues: not to mention the practice of Sokrates as described by Xenophon. In the Platonic Parmenidês, and Theætêtus, the season of youth is expressly pronounced to be that in which dialectic exercise is not merely appropriate, but indispensable to the subsequent attainment of truth.[183] Moreover, Plato puts into the mouth of Parmenides a specimen intentionally given to represent that dialectic exercise which will be profitable to youth. The specimen is one full of perplexing, though ingenious, subtleties: ending in establishing, by different trains of reasoning, the affirmative, as well as the negative, of several distinct conclusions. Not only it supplies no new positive certainty, but it appears to render any such consummation more distant and less attainable than ever.[184] It is therefore eminently open to the censure which Plato pronounces, in the passage just cited from his Republic, against dialectic as addressed to young men. The like remark may be made upon the numerous other dialogues (though less extreme in negative subtlety than the Parmenidês), wherein the Platonic Sokrates interrogates youths (or interrogates others, in the presence of youths) without any positive result: as in the Theætêtus, Charmidês, Lysis, Alkibiadês, Hippias, &c., to which we may add the conversations of the Xenophontic Sokrates with Euthydemus and others.[185]
[183] Plato, Parmenidês, pp. 135 D, 137 B. Theætêt. 146 A.
Proklus, in his Commentary on the Parmenidês (p. 778, Stallbaum), adverts to the passage of the Republic here discussed, and endeavours to show that it is not inconsistent with the Parmenidês. He states that the exhortation to practise dialectic debate in youth, as the appropriate season, must be understood as specially and exclusively addressed to a youth of the extraordinary mental qualities of Sokrates; while the passage in the Republic applies the prohibition only to the general regiment of Guardians. But this justification is noway satisfactory; for Plato in the Republic makes no exception in favour of the most promising Guardians. He lays down the position generally. Again, in the Parmenidês, we find the encouragement to dialectic debate addressed not merely to the youthful Sokrates, but to the youthful Aristoteles (p. 137 B). Moreover, we are not to imagine that all the youths who are introduced as respondents in the Platonic dialogues are implied as equal to Sokrates himself, though they are naturally represented as superior and promising subjects. Compare Plato, Sophistês, p. 217 E; Politikus, p. 257 E.
[184] Plato, Parmenid. p. 166 ad fin. εἰρήσθω τοίνυν τοῦτό τε καὶ ὅτι, ὡς ἔοικεν, ἓν εἴτ’ ἔστιν, εἰτε μὴ ἔστιν, αὐτό τε καὶ τἄλλα καὶ πρὸς αὐτὰ καὶ πρὸς ἄλληλα πάντα πάντως ἔστι τε καὶ οὐκ ἔστι, καὶ φαίνεται τε καὶ οὐ φαίνεται. Ἀληθέστατα.
[185] Xenophon, Memorab. iv. 2.