James Adam, The Republic of Plato

μετά γε φρονήσεως corresponds to φρονήσει in 582 A. Plato is taking the three requisites in order. The ἐμπειρία of the φιλόσοφος is alone intelligent, and, without φρόνησις, ἐμπειρία is no more than a sort of ἄτεχνος τριβή (Phaedr. 260 E: cf. Gorg. 463 B). It is indeed quite true, as Nettleship reminds us (Lect. and Rem. II p. 322), that the higher kind of man learns more from the experience which he shares with the lower kind without having to go through nearly the same amount of it.

ἀλλὰ μὴν κτλ. Bosanquet observes that “this is perhaps a good argument to prove that the man of culture is preeminently competent to appraise the value of different ideals of life, but it is not a good argument to prove that he is a good judge of degrees of agreeable feeling in lives fundamentally different from his own” (similarly Nettleship l. c. p. 321). True; but that is not the point. Plato is attempting to prove that the φιλόσοφος is the best judge, not of ‘the degrees of agreeable feeling’ experienced, in one particular kind of life, but of the relative pleasure of three different kinds of life, and his reasoning, granted that pleasures can be compared at all, is perfectly legitimate. Each of the three men pronounces his own life not merely pleasant, but pleasanter than those of the other two: how then are we to decide? Nothing but argument will help us, and the φιλόσοφος is the only one of the triad who possesses that weapon. It should be observed that throughout this part of the discussion Plato takes it for granted that some kinds of pleasure are in point of fact more pleasant than others. At present his object is to discover what these are, but in the argument which is still to come (585 B ff.), he grapples with the metaphysical question—for to him it was a question, not of psychology, but of metaphysics—and attempts to shew that pleasures contain more or less of pleasure according as there is in them more or less of truth.

ἔφαμεν κτλ. The reference is to 582 A. λόγοι means ‘rational arguments,’ ‘reasoning’ (cf. VI 511 B note), and τούτου is of course τοῦ φιλοσόφου, not τοῦ κρίνειν, as Stallbaum thinks.