Against the Ethicists, Book XI of Against the Learned Section 105

εἰ δὲ λέγοιεν εἶναι μέν τινα ζῷα φιλήδονα, τὸν δ’ ἄνθρωπον μὴ πάντως τοιοῦτον ὑπάρχειν, ἀναστρέψαντες καὶ ἡμεῖς ἐροῦμεν, οὐκ εἰ τινα τῶν ζῴων κατὰ φυσικὸν λόγον μεταδιώκει τὸ καλόν, εὐθέως καὶ ὁ ἄνθρωπος τοῦ αὐτοῦ στοχάζεται τέλους.

If they say that some animals are pleasure-loving but the human being is not invariably so, we too shall reverse the argument and say that, even if some animals naturally pursue the morally fine, it does not immediately follow that the human being aims at the same end.

S’ils disaient que certains animaux aiment le plaisir, mais que l’homme n’est pas nécessairement tel, nous retournerions leur argument : ce n’est pas parce que certains animaux poursuivent le beau moral selon une impulsion naturelle que l’homme vise aussitôt la même fin.