Aristotle, Eudemian Ethics

[1237b] [1] and the friend is an object of love to the friend qua dear to him but not qua musician or medical man, the pleasure of friendship is the pleasure derived from the person himself qua himself; for the friend loves him as himself, not because he is something else. Consequently if he does not take pleasure in him qua good, it is not the primary friendship. Nor ought any accidental quality to cause more hindrance than the friend's goodness causes delight; for surely, if a person is very evil-smelling, people cut him—he must be content with our goodwill, he must not expect our society!

This then is the primary friendship, which all people recognize. It is on account of it that the other sorts are considered to be friendship, and also that their claim is disputed—for friendship seems to be some thing stable, and only this friendship is stable; for a formed judgement is stable, and not doing things quickly or easily makes the judgement right. And there is no stable friendship without confidence, and confidence only comes with time; for it is necessary to make trial, as Theognis says:

“ You cannot know the mind of man nor woman
Before have you tried them as you try cattle.
”

Theog. 125f.

Those who become friends without the test of time are not real friends but only wish to be friends; and such a character very readily passes for friendship, [20] because when eager to be friends they think that by rendering each other all friendly services they do not merely wish to be friends but actually are friends. But as a matter of fact it happens in friendship as in everything else; people are not healthy merely if they wish to be healthy, so that even if people wish to be friends they are not actually friends already. A proof of this is that people who have come into this position without first testing one another are easily set at variance; for though men are not set at variance easily about things in which they have allowed each other to test them, in cases where they have not, whenever those who are attempting to set then, at variance produce evidence they may be convinced. At the same time it is manifest that this friendship does not occur between base people either; for the base and evil-natured man is distrustful towards everybody, because he measures other people by himself. Hence good men are more easily cheated, unless as a result of trial they are distrustful. But the base prefer the goods of nature to a friend, and none of them love people more than things; and so they are not friends, for the proverbial 'common property as between friends' is not realized in this way—the friend is made an appendage of the things, not the things of the friends.

Therefore the first kind of friendship does not occur between many men, because it is difficult to test many—one would have to go and live with each of them. Nor indeed should one exercise choice in the case of a friend in the same way as about a coat; although in all matters it seems the mark of a sensible man to choose the better of two things, and if he had been wearing his worse coat for a long time and had not yet worn his better one, the better one ought to be chosen—but you ought not in place of an old friend to choose one whom you do not know to be a better man.