"The human body is a machine which winds its own springs. It is the living image of perpetual movement. Without food, the soul pines away, goes mad, and dies exhausted. ...[H]eavy food makes a dull and heavy mind whose usual traits are laziness and indolence. ...We think we are, and in fact we are, good men, only as we are gay or brave; everything depends on the way our machine is running."