173
" Never stumble over fools. A fool is someone who doesn’t recognize a fool, and, even more, someone who does, but doesn’t get rid of him. Fools are dangerous to deal with, even superficially, and do much harm if you confide in them. For a while they are held back by their own caution or that of others, but the delay serves only to deepen their foolishness. Someone who has no reputation can do only harm to yours. Fools are always unfortunate—this is their burden—and their double misfortune sticks to them and rubs off on those they deal with. They have only one thing that isn’t completely bad: although the wise are of no use to them, they can be of use to the wise, as negative examples. "
― Baltasar Gracián , The Art of Worldly Wisdom