Plato, Laws 839d

ζῆν πράττουσαν τοῦτο, ἐλεγχθὲν δʼ ἔργῳ καὶ γενόμενον παρʼ ὑμῖν, ὅμως ἔτι τό γε γυναικῶν οὐδὲ ἐν ταῖς ὑμετέραις πόλεσιν δοκεῖ φύσιν ἔχειν γίγνεσθαι. ταύτῃ δʼ αὖ, διὰ τὴν τῆς ἀπιστίας ῥώμην, εἴρηκα ἀμφότερα ταῦτα εἶναι παγχάλεπα μεῖναι κατὰ νόμον. ὀρθῶς γε σὺ λέγων. ὡς δʼ οὖν οὐκ ἔστιν ὑπὲρ ἄνθρωπον, οἷόν τε δὲ γενέσθαι, βούλεσθε ὑμῖν πειραθῶ τινα λόγον ἐχόμενον πιθανότητος εἰπεῖν τινος; πῶς γὰρ οὔ;

for the whole State to be able to continue this practice constantly; and that, too, in spite of the evidence of facts and the existence of the practice in your countries; and even there, as applied to women, the practice is regarded as non-natural. Thus it was that, because of the strength of this unbelief, I said that it is most difficult to get both these matters permanently legalized. And you were right in that. Still, to show that it is not beyond the power of man, but possible, would you like me to try to state an argument which is not without some plausibility? Certainly.