Fear has been the original parent of superstition, and every new calamity urges trembling mortals to deprecate the wrath of their invisible enemies.
There are four types of men in this world: 1. The man who knows, and knows that he knows; he is wise, so consult him. 2. The man who knows, but doesn't know that he knows; help him not forget what he knows. 3. The man who knows not, and knows that he knows not; teach him. 4. Finally, there is the man who knows not but pretends that he knows; he is a fool, so avoid him.