Nick: Can God create a rock he can't lift?
Professor: Thomas Aquinas is not on the syllabus for this class.
Nick: Can you answer the question?
Professor: Mr. Haas...
Nick: If you answer yes, then there exists a rock in the world that God can't lift. Ergo, he's not all-powerful. Answer no, and he can't create such a rock, again, not all-powerful. So, the very idea of an all-powerful god is a human creation and a flawed one, at that.