Readers who can quote word for word from C.S. Lewis’s theological classic, Mere Christianity, or his science fiction novel, Perelandra, have often never read his work as a professional literary historian. They may not even recognize some of the neglected works discussed, here. Mark Neal and Jerry Root have done students of Lewis a great service, tracing the signature ideas in Lewis’s works of literary criticism and showing their relevance to Lewis’s more familiar books. Their thorough research...