Plato, Laws 839a

οὗ μήποτε φύσιν τὴν αὑτοῦ ῥιζωθὲν λήψεται γόνιμον, ἀπεχομένους δὲ ἀρούρας θηλείας πάσης ἐν ᾗ μὴ βούλοιο ἄν σοι φύεσθαι τὸ σπαρέν. ὁ δὴ νόμος οὗτος διηνεκὴς μὲν γενόμενος ἅμα καὶ κρατήσας, καθάπερ νῦν περὶ τὰς τῶν γονέων συμμείξεις κρατεῖ, ἐὰν καὶ περὶ τὰς ἄλλας νικήσῃ δικαίως, μυρία ἀγαθὰ ἔχει. κατὰ φύσιν μὲν γὰρ πρῶτον κεῖται, λύττης δὲ ἐρωτικῆς καὶ μανίας καὶ μοιχειῶν πασῶν καὶ πωμάτων καὶ σίτων εἴργεσθαι ποιεῖ τῶν ἀμέτρων

nor sowing seed on rocks and stones where it can never take root and have fruitful increase; and, on the other hand, by abstaining from every female field in which you would not desire the seed to spring up. This law, when it has become permanent and prevails—if it has rightly become dominant in other cases, just as it prevails now regarding intercourse with parents,—is the cause of countless blessings. For, in the first place, it follows the dictates of nature, and it serves to keep men from sexual rage and frenzy and all kinds of fornication, and from all excess in meats and drinks,