 His taxonomy begins with the premise that there are three main reasons why one person might like someone else. (The verb, “philein”, which is cognate to the noun “philia”, can sometimes be translated “like” or even “love”—though in other cases philia involves very little in the way of feeling.) One might like someone because he is good, or because he is useful, or because he is pleasant. And so there are three bases for friendships, depending on which of these qualities binds friends together. When two individuals recognize that the other person is someone of good character, and they spend time with each other, engaged in activities that exercise their virtues, then they form one kind of friendship. If they are equally virtuous, their friendship is perfect. If, however, there is a large gap in their moral development (as between a parent and a small child, or between a husband and a wife), then although their relationship may be based on the other person’s good character, it will be imperfect precisely because of their inequality.