Plato, Laws 672c

οἶδα, ὅτι πᾶν ζῷον, ὅσον αὐτῷ προσήκει νοῦν ἔχειν τελεωθέντι, τοῦτον καὶ τοσοῦτον οὐδὲν ἔχον ποτὲ φύεται· ἐν τούτῳ δὴ τῷ χρόνῳ ἐν ᾧ μήπω κέκτηται τὴν οἰκείαν φρόνησιν, πᾶν μαίνεταί τε καὶ βοᾷ ἀτάκτως, καὶ ὅταν ἀκταινώσῃ ἑαυτὸ τάχιστα, ἀτάκτως αὖ πηδᾷ. ἀναμνησθῶμεν δὲ ὅτι μουσικῆς τε καὶ γυμναστικῆς ἔφαμεν ἀρχὰς ταύτας εἶναι. μεμνήμεθα· τί δʼ οὔ; οὐκοῦν καὶ ὅτι τὴν ῥυθμοῦ τε καὶ ἁρμονίας αἴσθησιν

which properly belongs to it when fully developed; consequently, every creature, during the period when it is still lacking in its proper intelligence, continues all in a frenzy, crying out wildly, and, as soon as it can get on its feet, leaping wildly. Let us remember how we said that in this we have the origin of music and gymnastic. We remember that, of course. Do we not also remember how we said that from this origin there was implanted