καὶ γὰρ οὗτοι κτἑ.
: the ignorance of the trader is more fully set forth in Gorg.
517 d ff. τούτων γὰρ
(sc. σιτίων, ποτῶν, ἱματίων κτἑ.
) ποριστικὸν εἶναι ἢ κάπηλον ὄντα ἢ ἔμπορον . . ., οὐδὲν θαυμαστόν ἐστιν ὄντα τοιοῦτον δόξαι καὶ αὑτῷ καὶ τοῖς ἄλλοις θεραπευτὴν εἶναι σώματος, παντὶ τῷ μὴ εἰδότι, ὅτι ἔστι τις παρὰ ταύτας τέχνη γυμναστική τε καὶ ἰατρική, ἣ δὴ τῷ ὄντι ἐστὶ σώματος θεραπεία.— ὧν... λανγ̂γρεεκ>ἀγωγίμων
: depend. on ὅ τι
περὶ τὸ σῶμα
: with reference to the body.
In such expressions the prep. with the acc. brings out the quality of the adj. more distinctly and independently than would a simple gen., and is preferred by Plato, with whom however it becomes almost a mannerism. Cf. πρὸς τὴν ψυχήν
517 e εἰδέναι ὅ τι τὸ χρηστὸν καὶ πονηρὸν τῶν σιτίων ἢ ποτῶν ἐστὶν εἰς ἀρετὴν σώματος
: often means in each case, every time.ἐπαινοῦσι
: as Protagoras afterwards does, cf. 318 α ε
, 328 b