Plato, Laws 794d

γε μαθήσεως καὶ τὰ θήλεα, καὶ δὴ τά γε μάλιστα πρὸς τὴν τῶν ὅπλων χρείαν. τὸ γὰρ δὴ νῦν καθεστὸς περὶ τὰ τοιαῦτα ἀγνοεῖται παρὰ τοῖς πᾶσιν ὀλίγου. τὸ ποῖον; ὡς ἄρα τὰ δεξιὰ καὶ τὰ ἀριστερὰ διαφέροντά ἐσθʼ ἡμῶν φύσει πρὸς τὰς χρείας εἰς ἑκάστας τῶν πράξεων τὰ περὶ τὰς χεῖρας, ἐπεὶ τά γε περὶ πόδας τε καὶ τὰ κάτω τῶν μελῶν οὐδὲν διαφέροντα εἰς τοὺς πόνους φαίνεται· τὰ δὲ

and especially such as relate to the use of arms. For, as regards the view now prevalent regarding these matters, it is based on almost universal ignorance. What view? The view that, in the case of hands, right and left are by nature different in respect of their utility for special acts; but, as a matter of fact, in the case of the feet and the lower limbs there is plainly no difference in working capacity;