Aristotle, Eudemian Ethics

[1243b] [1] Hence it is clear how these cases must be decided. If they are moral friends, we must consider if their intentions are equal, and nothing else must be claimed by either from the other; and if they are friends on the ground of utility or civic friends, we must consider what form of agreement would have been profitable for them.¹ But if one says they are friends on one footing and the other on another, it is not honorable, when an active return is due, merely to make fine speeches, and similarly also in the other case²;— but since they did not provide for this in the contract, on the ground that it was a moral friendship, somebody must judge, and neither party must cheat by pretending; so that each must be content with his luck. But it is clear that moral friendship is a matter of intention, since even if a man after having received great benefits owing to inability did not repay them, but only repaid as much as he was able, he acts honorably; for even God is content with getting sacrifices in accordance with our ability. But a seller will not be satisfied if a man says he cannot pay more, nor will one who has made a loan.

In friendships not based on direct reciprocity³ many causes of recrimination occur, and it is not easy to see what is just; for it is difficult to measure by one given thing relations that are not directly reciprocal. This is how it happens in love affairs, since in them one party pursues the other as a pleasant person to live with, but sometimes the other the one as useful, and when the lover ceases to love, [20] he having changed the other changes, and then they calculate the quid pro quo, and quarrel as Pytho and Pammenes⁴ used, and as teacher and pupil do in general (for knowledge and money have no common measure), and as Herodicus⁵ the doctor did with the patient who offered to pay his fee with a discount, and as the harpist and the king fell out. The king associated with the harpist as pleasant and the harpist with the king as useful; but the king, when the time came for him to pay, made out that he was himself of the pleasant sort, and said that just as the harpist had given him pleasure by his singing, so he had given the harpist pleasure by his promises to him.⁶ Nevertheless here too it is clear how we must decide: here too we must measure by one standard, but by a ratio, not a number. For we must measure by proportion, as also the civic partnership is measured. For how is a shoemaker to be partner with a farmer unless their products are equalized by proportion? Therefore the measure for partnerships not directly reciprocal is proportion—for example if one party complains that he has given wisdom and the other says he has given the former money, what is the ratio of wisdom to being rich? and then, what is the amount given for each? for if one party has given half of the smaller amount but the other not even a small fraction of the larger, it is clear that the latter is cheating. But here too there is a dispute at the outset, if one says that they came together on grounds of utility and the other denies it and says it was on the basis of some other kind of friendship.