From Xenophon’s Memorobilia 1.6.13
In this passage Socrates argues against the sophists’ practice of taking money to teach about wisdom. In modern terms, Socrates might be seen as arguing against the commodification of our everyday relationships and exchanges. One can only imagine his responses to the notion of the ‘sharing economy’.
“Socrates responded to these things, “Antiphon, we share the belief that there is both a noble and a shameful way to share beauty and wisdom. For if someone offers beauty to anyone who wants it for money, people call him a prostitute. But if someone makes someone he knows who is a good and noble lover into a friend, we consider it prudent. It is the same way with wisdom: people call men who sell it to anyone who wishes for money a sophist [just like prostitutes] but whoever makes a friend of anyone he knows as capable and teaches him whatever good he can, we think that he has accomplished the duties of a good and noble citizen.
This, then, is how I proceed myself, Antiphon, just as some might get excited about a good horse, or a dog or a bird, I am so much more eager for good friends. And, if I know anything good, I teach it and I suggest others to them from whom I think they might gain some benefit concerning virtue. I also work through the treasures left by the wise men of old—those they have left in writing their books—opening them with my friends and picking out whatever good we discover. We consider this a great profit, if we become mutual friends* in this way.”
ὁ δὲ Σωκράτης πρὸς ταῦτα εἶπεν· ῏Ω ᾿Αντιφῶν, παρ’ ἡμῖν νομίζεται τὴν ὥραν καὶ τὴν σοφίαν ὁμοίως μὲν καλόν, ὁμοίως δὲ αἰσχρὸν διατίθεσθαι εἶναι. τήν τε γὰρ ὥραν ἐὰν μέν τις ἀργυρίου πωλῇ τῷ βουλομένῳ, πόρνον αὐτὸν ἀποκαλοῦσιν, ἐὰν δέ τις, ὃν ἂν γνῷ καλόν τε κἀγαθὸν ἐραστὴν ὄντα, τοῦτον φίλον ἑαυτῷ ποιῆται, σώφρονα νομίζομεν· καὶ τὴν σοφίαν ὡσαύτως τοὺς μὲν ἀργυρίου τῷ
βουλομένῳ πωλοῦντας σοφιστὰς [ὥσπερ πόρνους] ἀποκαλοῦσιν, ὅστις δὲ ὃν ἂν γνῷ εὐφυᾶ ὄντα διδάσκων ὅ τι ἂν ἔχῃ ἀγαθὸν φίλον ποιεῖται, τοῦτον νομίζομεν, ἃ τῷ καλῷ κἀγαθῷ πολίτῃ προσήκει, ταῦτα ποιεῖν. ἐγὼ δ’ οὖν καὶ αὐτός, ὦ ᾿Αντιφῶν, ὥσπερ ἄλλος τις ἢ ἵππῳ ἀγαθῷ ἢ κυνὶ ἢ ὄρνιθι ἥδεται, οὕτω καὶ ἔτι μᾶλλον ἥδομαι φίλοις ἀγαθοῖς, καὶ ἐάν τι ἔχω ἀγαθόν, διδάσκω, καὶ ἄλλοις συνίστημι παρ’ ὧν ἂν ἡγῶμαι ὠφελήσεσθαί τι αὐτοὺς εἰς ἀρετήν· καὶ τοὺς θησαυροὺς τῶν πάλαι σοφῶν ἀνδρῶν, οὓς ἐκεῖνοι κατέλιπον ἐν βιβλίοις γράψαντες, ἀνελίττων κοινῇ σὺν τοῖς φίλοις διέρχομαι, καὶ ἄν τι ὁρῶμεν ἀγαθὸν ἐκλεγόμεθα· καὶ μέγα νομίζομεν κέρδος, ἐὰν ἀλλήλοις φίλοι* γιγνώμεθα.
* φίλοι: has a manuscript variant of ὠφέλιμοι. So the phrase could be “if we are/become beneficial to each other.”