Although it doesn't say those exact words in Proverbs, the general gist is that wisdom calls aloud on the streets yet no one seems to hear her. Wisdom hates foolishness. These two opposites can not exist together. A fool can't perceive that they are a fool so they go on acting the way they do, but a fool who knows they are a fool (and wants to do something about it), then maybe they aren't such a fool after all!
