Diogenes Laertius, Lives of the Philosophers (3.39-40)
Plato is said to have upbraided someone whom he saw playing dice. When the man responded that they were playing for small stakes, Plato responded, “but the habit itself is not a small thing.” When he was asked whether there would one day be reminiscences of him as there were for some of his predecessors, he responded, “First it is necessary to make a name, and then many reminiscences will follow.” Once, when Xenocrates came in, he asked him to punish his slave, saying that he himself wasn’t able to do it because he was angry. But he said to one of them, “You would have been punished if I hadn’t been in a range.”
Once, when he sat upon a horse, he immediately got back off, saying that he needed to take care not to be taken by horse pride. His advice to drunkards was to look at themselves in the mirror, for they would then abandon that unwholesome pursuit. He said that drinking to drunkenness was unbecoming for everyone except at festivals held in honor of the god who gives the wine. He also disapproved of excessive sleep. He says in The Laws, “A sleeping person is good for nothing.” Plato also contended that the truth was more pleasing than other sounds. Others say that he claimed that speaking the truth was the finest thing. In The Laws, he writes thus on the subject of truth: “Stranger, the truth is a fine and stable thing. Yet it is not easy to persuade people of it.”
He wanted to leave some remembrance of himself behind either in his friends or in his books. According to some people, he was often in the habit of withdrawing into seclusion.
῾Ο γοῦν Πλάτων λέγεται θεασάμενός τινα κυβεύοντα αἰτιάσασθαι· τοῦ δὲ εἰπόντος ὡς ἐπὶ μικροῖς, “ἀλλὰ τό γ’ ἔθος,” εἰπεῖν, “οὐ μικρόν.” ἐρωτηθεὶς εἰ ἀπομνημονεύματα αὐτοῦ ἔσται ὥσπερ τῶν πρότερον ἀπεκρίνατο· “ὀνόματος δεῖ τυχεῖν πρῶτον, εἶτα πολλὰ ἔσται.” εἰσελθόντος ποτὲ Ξενοκράτους εἶπε μαστιγῶσαι τὸν παῖδα· αὐτὸν γὰρ μὴ δύνασθαι διὰ τὸ ὠργίσθαι. ἀλλὰ καὶ πρός τινα τῶν παίδων, “μεμαστίγωσο ἄν,” εἶπεν, “εἰ μὴ ὠργιζόμην.” ἐφ’ ἵππου καθίσας εὐθέως κατέβη φήσας εὐλαβεῖσθαι μὴ ἱπποτυφίᾳ ληφθῇ. τοῖς μεθύουσι συνεβούλευε κατοπτρίζεσθαι· ἀποστήσεσθαι γὰρ τῆς τοιαύτης ἀσχημοσύνης. πίνειν δ’ εἰς μέθην οὐδαμοῦ πρέπον ἔλεγε πλὴν ἐν ταῖς ἑορταῖς τοῦ καὶ τὸν οἶνον δόντος θεοῦ. καὶ τὸ πολλὰ δὲ καθεύδειν ἀπήρεσκεν αὐτῷ. ἐν γοῦν τοῖς Νόμοις (vii. 808b) φησί· “κοιμώμενος οὐδεὶς οὐδενὸς ἄξιος·” εἶναί τε ἥδιον τῶν ἀκουσμάτων τὴν ἀλήθειαν· οἱ δὲ τὸ λέγειν τἀληθῆ. καὶ περὶ ἀληθείας δ’ ἐν τοῖς Νόμοις φησὶν οὕτως (ii. 663e)· “καλὸν μὲν ἡ ἀλήθεια, ὦ ξένε, καὶ μόνιμον· ἔοικε μὴν οὐ ῥᾴδιον <εἶναι> πείθειν.” ἀλλὰ καὶ ἠξίου μνημόσυνον αὑτοῦ λείπεσθαι ἢ ἐν φίλοις ἢ ἐν βιβλίοις· ἐξετόπιζε καὶ αὐτὸς τὰ πλεῖστα, καθά τινες φασί.