Plato, Letters 326c

καὶ ὅσα τούτῳ ἐπιτηδεύματα συνέπεται τῷ βίῳ· ἐκ γὰρ τούτων τῶν ἐθῶν οὔτʼ ἂν φρόνιμος οὐδείς ποτε γενέσθαι τῶν ὑπὸ τὸν οὐρανὸν ἀνθρώπων ἐκ νέου ἐπιτηδεύων δύναιτο—οὐχ οὕτως θαυμαστῇ φύσει κραθήσεται—σώφρων δὲ οὐδʼ ἂν μελλήσαι ποτὲ γενέσθαι, καὶ δὴ καὶ περὶ τῆς ἄλλης ἀρετῆς ὁ αὐτὸς λόγος ἂν εἴη, πόλις τε οὐδεμία ἂν ἠρεμήσαι κατὰ νόμους οὐδʼ οὑστινασοῦν ἀνδρῶν οἰομένων ἀναλίσκειν μὲν δεῖν

and all the practices which accompany this mode of living. For not a single man of all who live beneath the heavens could ever become wise if these were his practices from his youth, since none will be found to possess a nature so admirably compounded; nor would he ever be likely to become temperate; and the same may truly be said of all other forms of virtue. And no State would remain stable under laws of any kind, if its citizens, while supposing that they ought to spend everywhere to excess,