Plato, Letters 334c

ὀνείδους γεγόνατον τῇ πόλει τὼ Δίωνα ἀποκτείναντε, ὡς ἐλλογίμω πώποτε ἄνδρε γενομένω.ταῦτα εἴρηται πάντα τῆς συμβουλῆς ἕνεκα τῶν Διωνείων φίλων καὶ συγγενῶν· συμβουλεύω δὲ δή τι πρὸς τούτοις τὴν αὐτὴν συμβουλὴν καὶ λόγον τὸν αὐτὸν λέγων ἤδη τρίτον τρίτοις ὑμῖν. μὴ δουλοῦσθαι Σικελίαν ὑπʼ ἀνθρώποις δεσπόταις, μηδὲ ἄλλην πόλιν, ὅ γʼ ἐμὸς λόγος, ἀλλʼ ὑπὸ νόμοις· οὔτε γὰρ τοῖς δουλουμένοις οὔτε τοῖς δουλωθεῖσιν ἄμεινον,

of Dion are not important enough to cast a reproach upon our city, as though they had ever yet shown themselves men of mark. All this has been said by way of counsel to Dion’s friends and relatives. And one piece of counsel I add, as I repeat now for the third time to you in the third place the same counsel as before, and the same doctrine. Neither Sicily, nor yet any other State—such is my doctrine—should be enslaved to human despots but rather to laws; for such slavery is good neither for those who enslave nor those who are enslaved—