Plato, Letters 328b

συμβῆναι γενομένους. τὰ μὲν δὴ παρακελεύματα ἦν ταῦτά τε καὶ τοιαῦτα ἕτερα πάμπολλα, τὴν δʼ ἐμὴν δόξαν τὸ μὲν περὶ τῶν νέων, ὅπῃ ποτὲ γενήσοιτο, εἶχεν φόβος—αἱ γὰρ ἐπιθυμίαι τῶν τοιούτων ταχεῖαι καὶ πολλάκις ἑαυταῖς ἐναντίαι φερόμεναι—τὸ δὲ Δίωνος ἦθος ἠπιστάμην τῆς ψυχῆς πέρι φύσει τε ἐμβριθὲς ὂν ἡλικίας τε ἤδη μετρίως ἔχον. ὅθεν μοι σκοπουμένῳ καὶ διστάζοντι πότερον εἴη πορευτέον καὶ ὑπακουστέον ἢ πῶς, ὅμως ἔρρεψε δεῖν, εἴ ποτέ τις τὰ διανοηθέντα

By these and a vast number of other like arguments Dion kept exhorting me; but as regards my own opinion, I was afraid how matters would turn out so far as the young people were concerned—for the desires of such as they change quickly, and frequently in a contrary direction; although, as regards Dion’s own character, I knew that it was stable by nature and already sufficiently mature. Wherefore as I pondered the matter and was in doubt whether I should make the journey and take his advice, or what, I ultimately inclined to the view that if we were ever to attempt to realize our theories