Perhaps the answer to these questions will appear if we ascertain what sort of things arouse liking or love. It seems that not everything is loved, but only what is lovable, and that this is either what is good, or pleasant, or useful. But useful may be taken to mean productive of some good or of pleasure, so that the class of things lovable as ends is reduced to the good and the pleasant.
Then, do men like what is really good, or what is good for them? for sometimes the two may be at variance; and the same with what is pleasant. Now it appears that each person loves what is good for himself, and that while what is really good is lovable absolutely, what is good for a particular person is lovable for that person. Further, each person loves not what is really good for himself, but what appears to him to be so; however, this will not affect our argument, for ‘lovable’ will mean ‘what appears lovable.’
There being then three motives of love, the term Friendship is not applied to love for inanimate objects, since here there is no return of affection, and also no wish for the good of the object—for instance, it would be ridiculous to wish well to a bottle of wine: at the most one wishes that it may keep well in order that one may have it oneself; whereas we are told that we ought to wish our friend well for his own sake. But persons who wish another good for his own sake, if the feeling is not reciprocated, are merely said to feel goodwill for him: only when mutual is such goodwill termed friendship.
And perhaps we should also add the qualification that the feeling of goodwill must be known to its object. For a man often feels goodwill towards persons whom he has never seen, but whom he believes to be good or useful, and one of these persons may also entertain the same feeling towards him. Here then we have a case of two people mutually well-disposed, whom nevertheless we cannot speak of as friends, because they are not aware of each other's regard. To be friends therefore, men must （1） feel goodwill for each other, that is, wish each other's good, and （2） be aware of each other's goodwill, and （3） the cause of their goodwill must be one of the lovable qualities mentioned above.