Perfect friendship exists between good men who are alike in their virtuousness. Wishing a friend good for his own sake is the highest degree of friendship. These friendships tend to be longlasting because virtue is something stable. Because both friends are good their friendship is both beneficial and pleasant as well, and thus they unite all the three reasons for friendship. Such friendships are rare because few people have the capability for this sort of friendship and they require time and familiarity to form.
Friendships based on pleasure can vary in their duration.
With regard to lovers, the friendship often fades away after the prime of youth is gone since the sight of the beloved no longer brings pleasure. Yet if the lovers are alike in character the friendship may last much longer. Only the friendship of good men is not harmed by slander. Bad men are friends either for the sake of pleasure or usefulness, while good men are friends for the sake of each other, and they are friends without qualification. Distance does not break a friendship but impedes its exercise.