Plato, Letters 327a

ἀρχὴν γεγονέναι τὴν τότε εἰς Σικελίαν ἐμὴν ἄφιξιν; ἐγὼ συγγενόμενος Δίωνι τότε νέῳ κινδυνεύω, τὰ δοκοῦντα ἐμοὶ βέλτιστα ἀνθρώποις εἶναι μηνύων διὰ λόγων καὶ πράττειν αὐτὰ συμβουλεύων, ἀγνοεῖν ὅτι τυραννίδος τινὰ τρόπον κατάλυσιν ἐσομένην μηχανώμενος ἐλάνθανον ἐμαυτόν. δίων μὲν γὰρ δή, μάλʼ εὐμαθὴς ὢν πρός τε τἆλλα καὶ πρὸς τοὺς τότε ὑπʼ ἐμοῦ λόγους γενομένους, οὕτως ὀξέως ὑπήκουσεν

the foundation of everything? When I associated with Dion, who was then a youth, instructing him verbally in what I believed was best for mankind and counselling him to realize it in action, it seems that I was not aware that I was, in a way, unwittingly contriving the future overthrow of the tyranny. For Dion in truth, being quick-witted, both in other respects and in grasping the arguments I then put forward, hearkened to me with a keenness and ardor that I have never yet found in any