Heraclitus, Homeric Problems 18.1
“The rational part of the soul, which is established in the head, [Plato] made the charioteer of the whole, when he says this (Tim. 90a2-5):
Concerning the most lordly part of our soul, we should concern of its form like this: God has granted to each of us that very spirit which we say lives among us at the highest part of our body, to raise us from the earth closer to our relative, heaven, since we are not an earth-bound growth but a heavenly creature.
Plato sprinkles these things into his own dialogues from the Homeric epics as if drawing from a spring.”
Τὸ μέντοι λογικὸν μέρος τῆς ψυχῆς, ὃ ἐν τῇ κεφαλῇ καθίδρυτο, τῶν ὅλων πεποίηκεν ἡνίοχον οὑτωσὶ λέγων·
Περὶ δὲ τοῦ κυριωτάτου παρ’ ἡμῖν ψυχῆς εἴδους δια-
νοεῖσθαι δεῖ τῇδε, ὡς ἄρα αὐτὸ δαίμονα θεὸς ἑκάστῳ δέδωκε,
τοῦτο ὃ δὴ φαμὲν οἰκεῖν μὲν ἡμῶν ἐπ’ ἄκρῳ τῷ σώματι,
πρὸς δὲ τὴν ἐν οὐρανῷ ξυγγένειαν ἀπὸ γῆς ἡμᾶς αἴρειν
ὡς ὄντας φυτὸν οὐκ ἐπίγειον, ἀλλ’ οὐράνιον.
Ταῦτα τοίνυν ὥσπερ ἐκ πηγῆς τῶν ῾Ομηρικῶν ἐπῶν εἰς τοὺς ἰδίους διαλόγους ὁ Πλάτων μετήρδευσεν.