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. W