Strangely enough, it is a particularly petty and mean attitude that befriends a third element for the sake of annoying a second: indifference to the moral autonomy of altruism cannot appear more sharply than in this exploitation of altruism. And it is doubly significant that the purpose of annoying one's adversary can be achieved by favoring either one's friend or one's enemy.

Georg Simmel, The Sociology of Georg Simm…, loc. 4428