 When Aristotle begins his discussion of friendship, he introduces a notion that is central to his understanding of this phenomenon: a genuine friend is someone who loves or likes another person for the sake of that other person. Wanting what is good for the sake of another he calls “good will” (eunoia), and friendship is reciprocal good will, provided that each recognizes the presence of this attitude in the other. Does such good will exist in all three kinds of friendship, or is it confined to relationships based on virtue? At first, Aristotle leaves open the first of these two possibilities. He says: