Letter 1644: I consider the truest rule of friendship to be the one who agrees with his brothers without making excuses, who...

To Lampretius, deacon. I consider the straightest rule of friendship to be this: the man who without pretext is in harmony with the brethren, who neither draws friendships to himself by flattery nor secretly carries on enmities, but who keeps his soul bare toward all men, being simple in his judgment, simple in his tongue, and simpler still in his manner of life.

Εγὼ κανόνα φιλίας εἰθύτατον ἡγοῦμαι τὸν ἀπροφασίστως μὲν τοῖς ἀδελφοῖς συμπνέοντα, μήτε δὲ κολακείᾳ τὰς φιλίας προσαγόμενον, μήτε λάθρα μεταχειριζόμενον τὰς ἔχθρας· ἀλλὰ πρὸς ἅπαντα τὴν ψυχὴν γυμνὸν, ἁπλοῦν μὲν τυγχάνοντα τὴν γνώμην, ἁπλοῦν δὲ τὴν γλῶτταν, ἁπλούστερον δὲ ἔτι μᾶλλον τὸν βίον.