Letter 81 (§11)

“Now some person will reckon this remark as one of the generally surprising statements such as we Stoics are wont to make and such as the Greeks call “paradoxes,” and will say: “Do you maintain, then, that only the wise man knows how to return a favour? Do you maintain that no one else knows how to make restoration to a creditor for a debt? Or, on buying a commodity, to pay full value to the seller?” In order not to bring any odium upon myself, let me tell you that Epicurus says the same thing. At any rate, Metrodorus remarks that only the wise man knows how to return a favour.”