Friendship depends more on loving than on being loved. Thus loving is the virtue of a friend. It is those who have this disposition to love according to merit who are enduring friends. This disposition is also that which allows unequals to be friends, for through this disposition they can be equalized. Good men neither err nor allow their friends to err.
Wicked men tend to have short friendships based on enjoying each other's evil habits.
Friendships based on usefulness or pleasure last only as long as the relationship is useful or pleasant. Friendships based on useful usually arise between those of contrary needs. The degree of injustice of a harm done to another depends on the degree of friendship that exists between the two people. Political associations are formed for the sake of the expedient, and all other associations are a subdivision of this. The kinds of friendship that exists among those in the association corresponds to the type of association.