Plato, Laws 636a

ὥσπερ τὰ περὶ τὸν πόλεμον νυνδή; σχεδὸν οὐ ῥᾴδιον· ἀλλʼ ἔοικεν γὰρ τά τε συσσίτια καὶ τὰ γυμνάσια καλῶς ηὑρῆσθαι πρὸς ἀμφοτέρας. ἔοικεν δῆτα, ὦ ξένοι, χαλεπὸν εἶναι τὸ περὶ τὰς πολιτείας ἀναμφισβητήτως ὁμοίως ἔργῳ καὶ λόγῳ γίγνεσθαι· κινδυνεύει γάρ, καθάπερ ἐν τοῖς σώμασιν, οὐ δυνατὸν εἶναι προστάξαι τι πρὸς ἓν σῶμα ἓν ἐπιτήδευμα, ἐν ᾧ οὐκ ἂν φανείη ταὐτὸν τοῦτο τὰ μὲν βλάπτον τὰ ἡμῶν σώματα,

as we found just now in regard to their military organization? Hardly an easy matter! Yet probably the common meals and the gymnasia are well devised to foster both these virtues. In truth, Strangers, it seems a difficult thing for State institutions to be equally beyond criticism both in theory and in practice. Their case resembles that of the human body, where it seems impossible to prescribe any given treatment for each case without finding that this same prescription is partly beneficial and partly injurious to the body.