Select your Friends. Only after passing the matriculation of experience and the examination of fortune will they be graduates not alone in affection but in discernment. Though this is the most important thing in life, it is the one least cared for. Intelligence brings friends to some, chance to most. Yet a man is judged by his friends, for there was never agreement between
wise men and fools. At the same time, to find pleasure in a man’s society is no proof of near friendship: it may come from the pleasantness of his company more than from trust in his capacity.
There are some friendships legitimate, others illicit; the latter for pleasure, the former for their fecundity of ideas and motives. Few are the friends of a man’s self, most those of his circumstances. The insight of a true friend is more useful than the goodwill of others: therefore gain them by choice, not by chance. A wise friend wards off worries, a foolish one brings them about. But do not wish them too much luck, or you may lose them.Gracian, The Art of Worldly Wisdom