Clive Staples Lewis was a British writer, literary scholar, and Anglican lay theologian. He held academic positions in English literature at both Oxford University and Cambridge University. He is best known as the author of The Chronicles of Narnia, but he is also noted for his other works of fiction, such as The Screwtape Letters and The Space Trilogy, and for his non-fiction Christian apologetics, including Mere Christianity, Miracles, and The Problem of Pain.