“Humans are amphibians...half spirit and half animal...as spirits they belong to the eternal world, but as animals they inhabit time. This means that while their spirit can be directed to an eternal object, their bodies, passions, and imaginations are in continual change, for to be in time, means to change. Their nearest approach to constancy, therefore, is undulation--the repeated return to a level from which they repeatedly fall back, a series of troughs and peaks.”

British author, literary scholar, and Anglican lay theologian

C. S. Lewis was a British author, literary scholar, and Anglican lay theologian. He held posts in English literature at Magdalen College, Oxford, and later at Magdalene College, Cambridge. He is best known for The Chronicles of Narnia. Lewis also wrote The Screwtape Letters and the Space Trilogy, along with Christian apologetic works such as Mere Christianity, Miracles, and The Problem of Pain. His writing ranges from imaginative fiction to religious argument, and much of it reflects his interest in Christian belief and moral questions.