Book 8
4
As then friendship consists more especially in bestowing affection, and as we praise men for loving their friends, affection seems to be the mark of a good friend. Hence it is friends that love each other as each deserves who continue friends and whose friendship is lasting.
5
Also it is by rendering affection in proportion to desert that friends who are not equals may approach most nearly to true friendship, since this will make them equal. Amity consists in equality and similarity, especially the similarity of those who are alike in virtue; for being true to themselves, these also remain true to one another, and neither request nor render services that are morally degrading. Indeed they may be said actually to restrain each other from evil: since good men neither err themselves nor permit their friends to err. Bad men on the other hand have no constancy in friendship, for they do not even remain true to their own characters; but they can be friends for a short time, while they take pleasure in each other’s wickedness.
