Part I of the apophthegmata attributed to Aristotle by Diogenes Laertius.
“These very nice sayings are attributed to him:
When asked what profit is gained by those who tell lies, he said: ‘that whenever they speak the truth, they are not believed.’
Once, he was reproached because he gave charity to a lowly person, so he said, ‘I gave charity to a man, not a way of life.’
He always used to tell his friends and students, whenever and wherever he happened to be lecturing, that ‘as light comes to sight from the air, so it comes to the mind from mathematics.’*
Very often, referring to the Athenians, he said, ‘they discovered wheat and laws: they used the wheat, not so much the laws.’
He used to say, ‘the roots of education are bitter, but the fruit is sweet.’
When asked what gets old quickly, he said, ‘gratitude.’
When asked what is hope, he said, ‘a waking dream.’
When Diogenes offered him a dried fig, he knew if he didn’t take it, Diogenes would have some joke ready to go. So he took it and said, ‘Diogenes ruined the fig as well as the joke.’ Another time he offered them, he took them and, raising them up as if they were children, he said, ‘Great Diogenes!’
He said three things are required for education: nature, study, and practice.
When he heard that someone was saying bad things about him behind his back, he said, ‘let him whip me when I’m not around.’
He used to say beauty was a better recommendation than any letter. Some people say Diogenes defined it this way, but he said good looks are ‘a gift from god,’ Socrates, ‘a short-lived tyranny,’ Plato, ‘an advantage of nature,’ Theophrastus, ‘a silent deception,’ Theocritus, ‘a penalty made of ivory,’ Carneades, ‘a king without a body-guard.’
When asked how the educated differ from the uneducated, he said, ‘as much as the living from the dead.’
He used to say, ‘education is an adornment in good times and a refuge in bad ones;’ and that children’s teachers are more valuable than those who only gave them birth: for the one gives you a chance to live, the other to live well.
To someone who bragged that he was from a great city, he said, ‘one needn’t look into this, but rather, who is it who is worthy of a great heritage.’
When asked what a friend is, he said, ‘one soul dwelling in two bodies.’
He used to say, ‘there are two kinds of people: those who are as restrained as someone who will live forever, and those who are as excessive as someone who will die tomorrow.’
To the person who was curious why we spend so much time in the company of what is beautiful, he said, ‘that’s a blind man’s question.’”
*or perhaps, “studies”
 Ἀναφέρεται δ᾽ εἰς αὐτὸν καὶ ἀποφθέγματα κάλλιστα ταυτί. ἐρωτηθεὶς τί περιγίνεται κέρδος τοῖς ψευδομένοις, "ὅταν," ἔφη, "λέγωσιν ἀληθῆ, μὴ πιστεύεσθαι." ὀνειδιζόμενός ποτε ὅτι πονηρῷ ἀνθρώπῳ ἐλεημοσύνην ἔδωκεν, "οὐ τὸν τρόπον," εἶπεν, "ἀλλὰ τὸν ἄνθρωπον ἠλέησα." συνεχὲς εἰώθει λέγειν πρός τε τοὺς φίλους καὶ τοὺς φοιτῶντας αὐτῷ, ἔνθα ἂν καὶ ὅπου διατρίβων ἔτυχεν, ὡς ἡ μὲν ὅρασις ἀπὸ τοῦ περιέχοντος [ἀέρος] λαμβάνει τὸ φῶς, ἡ δὲ ψυχὴ ἀπὸ τῶν μαθημάτων. πολλάκις δὲ καὶ ἀποτεινόμενος τοὺς Ἀθηναίους ἔφασκεν εὑρηκέναι πυροὺς καὶ νόμους: ἀλλὰ πυροῖς μὲν χρῆσθαι, νόμοις δὲ μή.
 Τῆς παιδείας ἔφη τὰς μὲν ῥίζας εἶναι πικράς, τὸν δὲ καρπὸν γλυκύν. ἐρωτηθεὶς τί γηράσκει ταχύ, "χάρις," ἔφη. ἐρωτηθεὶς τί ἐστιν ἐλπίς, "ἐγρηγορότος," εἶπεν, "ἐνύπνιον." Διογένους ἰσχάδ᾽ αὐτῷ διδόντος νοήσας ὅτι, εἰ μὴ λάβοι, χρείαν εἴη μεμελετηκώς, λαβὼν ἔφη Διογένην μετὰ τῆς χρείας καὶ τὴν ἰσχάδα ἀπολωλεκέναι: πάλιν τε διδόντος λαβὼν καὶ μετεωρίσας ὡς τὰ παιδία εἰπών τε "μέγας Διογένης," ἀπέδωκεν αὐτῷ. τριῶν ἔφη δεῖν παιδείᾳ, φύσεως, μαθήσεως, ἀσκήσεως. ἀκούσας ὑπό τινος λοιδορεῖσθαι, "ἀπόντα με," ἔφη, "καὶ μαστιγούτω." τὸ κάλλος παντὸς ἔλεγεν ἐπιστολίου συστατικώτερον.
 οἱ δὲ οὕτω μὲν Διογένην φασὶν ὁρίσασθαι, αὐτὸν δὲ θεοῦ δῶρον εἰπεῖν εὐμορφίαν: Σωκράτην δὲ ὀλιγοχρόνιον τυραννίδα: Πλάτωνα προτέρημα φύσεως: Θεόφραστον σιωπῶσαν ἀπάτην: Θεόκριτον ἐλεφαντίνην ζημίαν: Καρνεάδην ἀδορυφόρητον βασιλείαν. ἐρωτηθεὶς τίνι διαφέρουσιν οἱ πεπαιδευμένοι τῶν ἀπαιδεύτων, "ὅσῳ," εἶπεν, "οἱ ζῶντες τῶν τεθνεώτων." τὴν παιδείαν ἔλεγεν ἐν μὲν ταῖς εὐτυχίαις εἶναι κόσμον, ἐν δὲ ταῖς ἀτυχίαις καταφυγήν. τῶν γονέων τοὺς παιδεύσαντας ἐντιμοτέρους εἶναι τῶν μόνον γεννησάντων: τοὺς μὲν γὰρ τὸ ζῆν, τοὺς δὲ τὸ καλῶς ζῆν παρασχέσθαι. πρὸς τὸν καυχώμενον ὡς ἀπὸ μεγάλης πόλεως εἴη, "οὐ τοῦτο," ἔφη, "δεῖ σκοπεῖν, ἀλλ᾽ ὅστις μεγάλης πατρίδος ἄξιός ἐστιν."
 ἐρωτηθεὶς τί ἐστι φίλος, ἔφη, "μία ψυχὴ δύο σώμασιν ἐνοικοῦσα." τῶν ἀνθρώπων ἔλεγε τοὺς μὲν οὕτω φείδεσθαι ὡς ἀεὶ ζησομένους, τοὺς δὲ οὕτως ἀναλίσκειν ὡς αὐτίκα τεθνηξομένους. πρὸς τὸν πυθόμενον διὰ τί τοῖς καλοῖς πολὺν χρόνον ὁμιλοῦμεν, "τυφλοῦ," ἔφη, "τὸ ἐρώτημα."