Iamblichus, Life of Pythagoras 42
“For when the barbarians and the Greeks were struggling against each other around Troy because of one man’s lack of self-control they endured the most terrible calamities—some in war, some in the return home—and the god assigned a punishment for that single injustice for one thousand and ten years, providing an oracle for the sack of Troy and requesting the journey of maidens from Locris to the temple of Athena in Troy.
[Pythagoras] used to harangue the young men regarding education too, demanding that they consider how strange it would be to judge rational thought the most desirable of all things when one must judge concerning everything else using it, yet people spend no time nor toil in practicing it. And this is when care given to the body is similar to worthless friends in abandoning you quickly; education, however, is like the most good and noble companions who stay by your side right up to death—and, for some, it provides immortal glory after life is over.”
τῶν γὰρ βαρβάρων καὶ τῶν ῾Ελλήνων περὶ τὴν Τροίαν ἀντιταξαμένων ἑκατέρους δι’ ἑνὸς ἀκρασίαν ταῖς δεινοτάταις περιπεσεῖν συμφοραῖς, τοὺς μὲν ἐν τῷ πολέμῳ, τοὺς δὲ κατὰ τὸν ἀνάπλουν, καὶ μόνης <ταύτης> τῆς ἀδικίας τὸν θεὸν δεκετῆ καὶ χιλιετῆ τάξαι τὴν τιμωρίαν, χρησμῳδήσαντα τήν τε τῆς Τροίας ἅλωσιν καὶ
τὴν τῶν παρθένων ἀποστολὴν παρὰ τῶν Λοκρῶν εἰς τὸ τῆς ᾿Αθηνᾶς τῆς ᾿Ιλιάδος ἱερόν. παρεκάλει δὲ τοὺς νεανίσκους καὶ πρὸς τὴν παιδείαν, ἐνθυμεῖσθαι κελεύων ὡς ἄτοπον ἂν εἴη πάντων μὲν σπουδαιότατον κρίνειν τὴν διάνοιαν καὶ ταύτῃ βουλεύεσθαι περὶ τῶν ἄλλων, εἰς δὲ τὴν ἄσκησιν τὴν ταύτης μηδένα χρόνον μηδὲ πόνον ἀνηλωκέναι, καὶ ταῦτα τῆς μὲν τῶν σωμάτων ἐπιμελείας τοῖς φαύλοις τῶν φίλων ὁμοιουμένης καὶ ταχέως ἀπολειπούσης, τῆς δὲ παιδείας καθάπερ οἱ καλοὶ κἀγαθοὶ τῶν ἀνδρῶν μέχρι θανάτου παραμενούσης, ἐνίοις δὲ καὶ μετὰ τὴν τελευτὴν ἀθάνατον δόξαν περιποιούσης.