Plato, Letters 339b

Σικελίᾳ περὶ πλείστου ποιεῖσθαι, τῶν Ἀρχύτῃ συγγεγονότων ἕνα, καὶ ἄλλους γνωρίμους τῶν ἐν Σικελίᾳ· οὗτοι δὲ ἡμῖν ἤγγελλον πάντες τὸν αὐτὸν λόγον, ὡς θαυμαστὸν ὅσον Διονύσιος ἐπιδεδωκὼς εἴη πρὸς φιλοσοφίαν. ἔπεμψεν δὲ ἐπιστολὴν πάνυ μακράν, εἰδὼς ὡς πρὸς Δίωνα διεκείμην καὶ τὴν αὖ Δίωνος προθυμίαν τοῦ ἐμὲ πλεῖν καὶ εἰς Συρακούσας ἐλθεῖν· πρὸς γὰρ δὴ πάντα ταῦτα ἦν παρεσκευασμένη τὴν ἀρχὴν ἔχουσα ἡ ἐπιστολή, τῇδέ πῃ φράζουσα— Διονύσιος

and other Sicilians of my acquaintance; and all these were giving me the same account, how that Dionysius had made marvellous progress in philosophy. And he sent an exceedingly long letter, since he knew how I was disposed towards Dion and also Dion’s eagerness that I should make the voyage and come to Syracuse; for his letter was framed to deal with all these circumstances, having its commencement couched in some such terms as these—Dionysius to Plato, followed by