Book 8: Friendship or Love.
Chapter 7: Of friendship between unequal persons and its rule of proportion. Limits within which this is possible.
But, besides these, there is another kind of friendship, in which the persons are unequal, as that of a father for a son, and generally of an elder for a younger person, or of a man for a woman, or of a ruler of any kind for a subject.
These also are different from one another; for that of parent for child is not the same as that of ruler for subject, nor even that of father for son the same as that of son for father, nor that of man for woman the same as that of woman for man. For each of these classes has a different excellence and a different function, and the grounds of their affection are different; therefore their love and their friendship also are different. What each does for the other, then, is not the same, nor should they expect it to be the same; but when children give to their parents what they owe to those who begat them, and parents on their part give what they owe to their children, then such friendship will be lasting, and what it ought to be. But in all friendships based on inequality, the love on either side should be proportional—I mean that the better of the two (and the more useful, and so on in each case) should receive more love than he gives; for when love is proportioned to desert, then there is established a sort of equality, which seems to be a necessary condition of friendship.
But there seems to be a difference between the equality that prevails in the sphere of justice and that which prevails in friendship: for in the sphere of justice the primary sense of “equal” [or “fair,” ἴσον] is “proportionate to merit,” and “equal in quantity” is only the secondary sense; but in friendship “equal in quantity” is the primary, and “proportionate to merit” the secondary sense.
This is plainly seen in cases where there comes to be a great distance between the persons in virtue, or vice, or wealth, or in any other respect; for they no longer are, nor expect to be, friends. It is most plainly seen in the case of the gods; for they have the greatest superiority in all good things. But it is seen also in the case of princes; for here also those who are greatly inferior do not claim their friendship; nor do people of no consideration expect to be friends with the best and wisest in the state. It is impossible accurately to determine the limits within which friendship may subsist in such cases: many things may be taken away, and it may remain; but again, if a person be very far removed, as God is, it can no longer be.
This has suggested the objection that, after all, a friend does not wish his friend the greatest of all goods, that he should become a god; for then he would lose a friend—that is, a good; for a friend is a good thing. If then we were right in saying that a friend wishes good to his friend for his (the friend’s) sake, we must add, “the friend remaining what he is:” so far as is compatible with his being a man, he will wish him the greatest good—but perhaps not everything that is good; for every man wishes good most of all to himself.