As already stated, there are three forms of friendship, each of which is divided into two kinds, that between equals and that between unequals. In equal friendships based on utility or pleasure there is a moral obligation on each party to provide the other with equivalent service or pleasure in compensation for what he has received. There may or may not be prearranged conditions in such relationships and often the thing exchanged is intangible, but in cases where one or both parties feel there has not been an equivalent exchange it is likely that the friendship will break up. Needless to say, an element of good will should enter into any evaluation of equivalence.
In true friendship between good men, complaints on this basis are rare. The moral intention of the giver serves as a standard for measuring equivalence since the decisive factor in virtue and character is moral choice. In true friendship the giver actually receives better than he gives, since, as a virtuous man, his end is to achieve the good and he is helped in the fulfillment of this aspiration by his friend.