Plato, Letters 310c

ἐξαίρετον ποιῇ. οὗτος δὲ ὁ λόγος σημαίνει, τὸ Δίωνα ἐξαίρετον εἶναι, ὅτι οὐκ ἄρχω ἐγὼ τῶν ἐμῶν ἐπιτηδείων· εἰ γὰρ ἦρχον ἐγὼ οὕτω τῶν τε ἄλλων καὶ σοῦ καὶ Δίωνος, πλείω ἂν ἦν ἡμῖν τε πᾶσιν ἀγαθὰ τοῖς τε ἄλλοις Ἕλλησιν, ὡς ἐγώ φημι. νῦν δὲ μέγας ἐγώ εἰμι ἐμαυτὸν παρέχων τῷ ἐμῷ λόγῳ ἑπόμενον. καὶ ταῦτα λέγω ὡς οὐχ ὑγιές τι Κρατιστόλου καὶ Πολυξένου πρὸς σὲ εἰρηκότων, ὧν φασὶ

Now your saying this, that Dion is excepted, implies that I have no control over my friends; for had I had this control over you and Dion, as well as the rest, more blessings would have come to us all and to the rest of the Greeks also, as I affirm. But as it is, my greatness consists in making myself follow my own instructions. However, I do not say this as though what Cratistolus and Polyxenus have told you is to be trusted; for it is said that