In the first installment of his space trilogy, Out of the Silent Planet, C. S. Lewis describes an alien world in which questions of personhood are much less ambiguous than they have become on Earth. The hero of the story, Ransom, learns through conversation with an alien beast that the concept of a "person" among humans has become clouded and "bent" by modern philosophy, and that the way to return to a healthy idea is to understand moral beings in absolute terms.