Plato, Letters 363b

περὶ δὲ δὴ τοῦ συμβόλου τοῦ περὶ τὰς ἐπιστολάς, ὅσας τε ἂν ἐπιστέλλω σπουδῇ καὶ ὅσας ἂν μή, οἶμαι μέν σε μεμνῆσθαι, ὅμως δʼ ἐννόει καὶ πάνυ πρόσεχε τὸν νοῦν· πολλοὶ γὰρ οἱ κελεύοντες γράφειν, οὓς οὐ ῥᾴδιον φανερῶς διωθεῖσθαι. τῆς μὲν γὰρ σπουδαίας ἐπιστολῆς θεὸς ἄρχει, θεοὶ δὲ τῆς ἧττον.οἱ πρέσβεις καὶ ἐδέοντο ἐπιστέλλειν σοι, καὶ εἰκός· πάνυ γὰρ προθύμως σὲ πανταχοῦ καὶ ἐμὲ ἐγκωμιάζουσιν, καὶ οὐχ ἥκιστα Φίλαγρος, ὃς τότε τὴν χεῖρα ἠσθένει. καὶ

Concerning the sign which indicates which of my letters are seriously written and which not, I suppose that you remember it, but none the less bear it in mind and pay the utmost attention; for there are many bidding me to write, whom it is not easy to repulse openly. God, then, is at the head of the serious letter, but gods of the less serious. The ambassadors requested me to write to you, and naturally so; for they are everywhere lauding both you and me with the utmost zeal; and not least Philagrus, who was then suffering with his hand. Philaides also,