James Adam, The Republic of Plato

ἐν ἑνὶ κτλ. The results of Book IV are foreshadowed more clearly in what follows. The notion that justice present in the individual keeps the individual at peace with himself is more fully developed in 441 D, and implicitly assumes a psychological theory like that in Book IV, where soul is shewn to have ‘parts’ (435 C ff.). Further, in Book IV, Plato first describes justice in the State, and afterwards justice in the individual, using the larger aggregate to assist him to find it in the smaller. The same method is observed here in the description of injustice, and afterwards in Books VIII and IX, where the varieties of ἀδικία in states and individuals are described. The present passage (351 A —352 A), in fact, contains the undeveloped germ of the whole method and doctrine of the Republic (with the exception of Books V—VII). Cf. Hirmer Entst. u. Kompos. d. Pl. Pol. p. 608.

μῶν μὴ (a strengthened num) occurs only twice in the Republic, here and in VI 505 C. In the later dialogues μῶν is especially frequent (Frederking in Fl. Jahrb. 1882 p. 539). A classified list of examples is given by Kugler de part. τοι eiusque comp. ap. Pl. usu p. 40.

οἵαν -- ποιεῖν. See cr. n. ποιεῖ would involve (as even Schneider admits) “durissimum et haud scio an vitiosum anacoluthon.” Cf. οἷοι μὴ ἀδικεῖν in 334 D. Tucker proposes to eject οἵαν and retain ποιεῖ, but the reading of II is preferable in every way. For the error see Introd. § 5.