Letter 758: Such has Diophantus been since boyhood: self-controlled, fair-minded, industrious, pleasing to the best men.

To Hierax. (362) Such was Diophantus from boyhood: temperate, fair-minded, fond of work, pleasing to the best men. If, then, the greater part of his virtue comes to him in his blood, you must receive the gratitude for it from both me and Diophantus; he received your good qualities through the mediation of his mother. I believe, then, that he is well-disposed toward me and will continue to be so. Let him, however, make his returns to me by attempting to speak [practicing oratory], and let him be released from all other concerns.

Ἱερακίῳ. (362) Τοιοῦτος ἦν ἐκ παιδὸς ὁ Διόφαντος· σώφρων, ἐπιεικής, ἐθελουργός, τοῖς βελτίστοις ἀρέσκων εἰ οὖν εἰς τὸ αἷμα τῆς ἀρετῆς τὸ πλέον ἔρχεται, σοὶ δεῖ τὴν χάριν ἔχειν κἀμὲ καὶ Διόφαντον τὰ σὰ καλὰ διὰ μέσης τῆς μητρὸς ἐδέξατο. εἶναι μὲν οὖν αὐτὸν εἰς ἐμὲ χρηστὸν καὶ ἔσεσθαι πιστεύω· ποιείσθω μέντοι πρὸς ἐμὲ τὰς ἀμοιβὰς ἀπὸ τοῦ πειρᾶσθαι λέγειν, τῶν δ’ ἄλλων ἀφείσθω φροντίδων.