Plato, Epinomis 982c

ἄριστον κατὰ τὸν ἄριστον βουλεύσηται νοῦν, τὸ τέλεον ἐκβαίνει τῷ ὄντι κατὰ νοῦν, καὶ οὐδὲ ἀδάμας ἂν αὐτοῦ κρεῖττον οὐδὲ ἀμεταστροφώτερον ἄν ποτε γένοιτο, ἀλλʼ ὄντως τρεῖς Μοῖραι κατέχουσαι φυλάττουσι τέλεον εἶναι τὸ βελτίστῃ βουλῇ βεβουλευμένον ἑκάστοις θεῶν. τοῖς δὲ ἀνθρώποις ἐχρῆν τεκμήριον εἶναι τοῦ νοῦν ἔχειν ἄστρα τε καὶ σύμπασαν ταύτην τὴν διαπορείαν, ὅτι τὰ αὐτὰ ἀεὶ πράττει διὰ τὸ βεβουλευμένα πάλαι πράττειν θαυμαστόν τινα χρόνον

the soul has taken the best counsel in accord with the best mind, comes out as the perfect thing in truth and in accord with mind, and not even adamant could ever prove stronger than it or more inalterable; but in fact the three Fates have it in hold, and keep watch that what has been decided by each of the gods with the best counsel shall be perfect. And men ought to have found proof of the stars and the whole of that travelling system being possessed of mind in the fact that they always do the same things because they do what has been decided long ago for an incalculable time,