I just figured since a favorite philosophers thread was started, why not a favorite sayings thread. So what is your favorite saying from a philosopher? You may give an explanation if you wish, but no explanation is required.

For a long while mine was "Know thyself" from Socrates, but since I've joined the forum I've been acquainted with a new saying that's currently my favorite from Voltaire, "God is a comedian playing for an audeince too afraid to laugh."