Plato, Laws 656b

πότερον εἰκὸς ἢ καὶ ἀναγκαῖον ταὐτὸν εἶναι ὅπερ ὅταν τις πονηροῖς ἤθεσιν συνὼν κακῶν ἀνθρώπων μὴ μισῇ, χαίρῃ δὲ ἀποδεχόμενος, ψέγῃ δὲ ὡς ἐν παιδιᾶς μοίρᾳ, ὀνειρώττων αὐτοῦ τὴν μοχθηρίαν; τότε ὁμοιοῦσθαι δήπου ἀνάγκη τὸν χαίροντα ὁποτέροις ἂν χαίρῃ, ἐὰν ἄρα καὶ ἐπαινεῖν αἰσχύνηται· καίτοι τοῦ τοιούτου τί μεῖζον ἀγαθὸν ἢ κακὸν φαῖμεν ἂν ἡμῖν ἐκ πάσης ἀνάγκης γίγνεσθαι; δοκῶ μὲν οὐδέν.

Is it not probable or rather inevitable that the result here will be exactly the same as what takes place when a man who is living amongst the bad habits of wicked men, though he does not really abhor but rather accepts and delights in those habits, yet censures them casually, as though dimly aware of his own turpitude? In such a case it is, to be sure, inevitable that the man thus delighted becomes assimilated to those habits, good or bad, in which he delights, even though he is ashamed to praise them. Yet what blessing could we name, or what curse, greater than that of assimilation which befalls us so inevitably? There is none, I believe.