“Protagoras of Abdera, the sophist, was also a follower of Democritus at home; and he spent time among the Persian magi as well when Xerxes invaded Greece. His father Maiandros had acquired more wealth than most in Thrace; he entertained Xerxes at his home and used gifts to ensure an audience for his son with the magi. The Persian magi do not teach even Persians unless the king says so.
It seems to me that when Protagoras used to say that he was whether there were gods on not he was borrowing it from the Persian education. For the magi worship the gods in the acts they perform secretly, but they do not confess open belief in the divine because they do not wish to seem to derive power from them. For saying this, Protagoras was exiled from all the lands under Athens’ power, after he was convicted according to some in a trial, but according to others there was a vote without a trial. He moved from shore to shore among the islands, all while watching out for Athenian triremes which were spread in every part of the sea. He drowned while sailing in a small skiff.
He was the first to give a lecture for a fee and as the first to give to the Greeks a practice which should not be criticized, since we pursue those things we paid for more eagerly than we welcome whatever comes free. Plato believed that while Protagoras spoke with dignity, he obscured himself with his dignity and was somewhat more verbose than was fit, and he characterized the type of man he was by using a long myth.”
[The last bit is a reference to Protagoras 349a and Gorgias 530c]
Πρωταγόρας δὲ ὁ ᾿Αβδηρίτης σοφιστὴς καὶ Δημοκρίτου μὲν ἀκροατὴς οἴκοι ἐγένετο, ὡμίλησε δὲ καὶ τοῖς ἐκ Περσῶν μάγοις κατὰ τὴν Ξέρξου ἐπὶ τὴν ῾Ελλάδα ἔλασιν. πατὴρ γὰρ ἦν αὐτῷ Μαίανδρος πλούτῳ κατεσκευασμένος παρὰ πολλοὺς τῶν ἐν τῇ Θρᾴκῃ, δεξάμενος δὲ καὶ τὸν Ξέρξην οἰκίᾳ τε καὶ δώροις τὴν ξυνουσίαν τῶν μάγων τῷ παιδὶ παρ’ αὐτοῦ εὕρετο. οὐ γὰρ παιδεύουσι τοὺς μὴ Πέρσας Πέρσαι μάγοι, ἢν μὴ ὁ βασιλεὺς ἐφῇ. τὸ δὲ ἀπορεῖν φάσκειν, εἴτε εἰσὶ θεοί, εἴτε οὐκ εἰσί, δοκεῖ μοι Πρωταγόρας ἐκ τῆς Περσικῆς παιδεύσεως παρανομῆσαι· μάγοι γὰρ ἐπιθειάζουσι μὲν οἷς ἀφανῶς δρῶσι, τὴν δὲ ἐκ φανεροῦ δόξαν τοῦ θείου καταλύουσιν οὐ βουλόμενοι δοκεῖν παρ’ αὐτοῦ δύνασθαι. διὰ μὲν δὴ τοῦτο πάσης γῆς ὑπὸ ᾿Αθηναίων ἠλάθη, ὡς μέν τινες, κριθείς, ὡς δὲ ἐνίοις δοκεῖ, ψήφου ἐπενεχθείσης μὴ κριθέντι. νήσους δὲ ἐξ ἠπείρων ἀμείβων καὶ τὰς ᾿Αθηναίων τριήρεις φυλαττόμενος πάσαις θαλάτταις ἐνεσπαρμένας κατέδυ πλέων ἐν ἀκατίῳ μικρῷ.
Τὸ δὲ μισθοῦ διαλέγεσθαι πρῶτος εὗρε, πρῶτος δὲ παρέδωκεν ῞Ελλησι πρᾶγμα οὐ μεμπτόν, ἃ γὰρ σὺν δαπάνῃ σπουδάζομεν, μᾶλλον ἀσπαζόμεθα τῶν προῖκα. γνοὺς δὲ τὸν Πρωταγόραν ὁ Πλάτων σεμνῶς μὲν ἑρμηνεύοντα, ἐνυπτιάζοντα δὲ τῇ σεμνότητι καί που καὶ μακρολογώτερον τοῦ συμμέτρου, τὴν ἰδέαν αὐτοῦ μύθῳ μακρῷ ἐχαρακτήρισεν.