Aristotle, Nicomachean Ethics
H. Rackham, Ed.

This form of friendship is perfect both in point of duration and of the other attributes¹ of friendship; and in all respects either party receives from the other the same or similar benefits, as it is proper that friends should do.

Friendship based on pleasure has a similarity to friendship based on virtue, for good men are pleasant to one another; and the same is true of friendship based on utility, for good men are useful to each other. In these cases also the friendship is most lasting when each friend derives the same benefit, for instance pleasure, from the other, and not only so, but derives it from the same thing, as in a friendship between two witty people, and not as in one between a lover and his beloved. These do not find their pleasure in the same things: the lover's pleasure is in gazing at his beloved, the loved one's pleasure is in receiving the attentions of the lover; and when the loved one's beauty fades, the friendship sometimes fades too, as the lover no longer finds pleasure in the sight of his beloved, and the loved one no longer receives the attentions of the lover; though on the other hand many do remain friends if as a result of their intimacy they have come to love each other's characters, both being alike in character.