Like Plato, C.S. Lewis believed that the human soul was made up of three parts — the head (the rational, reason-driven part of you), the belly (your appetites and base instincts), and the chest (the seat of virtue-seeking sentiments and well-tuned emotions). In order for your head to make your decisions, particularly the decision to live a virtuous life, rather than your decisions being driven by your belly, the head needs the aid of the chest, of right feeling.