"...There are four kinds of people in this world: cretins, fools, morons, and lunatics."

"And that covers everybody?"

"Oh, yes, including us. Or at least me. If you take a good look, everybody fits into one of these categories. Each of us is sometimes a cretin, a fool, a moron, or a lunatic. A normal person is just a reasonable mix of these components, these four ideal types."

Foucault's Pendulum
Umberto Eco