Which C.S. Lewis book contains the fictional demon Screwtape’s letters?

The Screwtape Letters is the C.S. Lewis book built around letters from the senior demon Screwtape. The letters offer advice to a junior tempter named Wormwood about undermining a human’s spiritual life.

Lewis published the work in 1942. The epistolary format lets him present Christian moral ideas indirectly, using demonic advice to expose pride, distraction, self-deception, and misplaced priorities. The book became one of his most popular and frequently discussed works.

Screwtape is not presented as a heroic or admirable figure. The satire depends on readers recognizing that the demons’ apparently practical guidance reveals the destructive habits Lewis is criticizing. The book is also distinct from Lewis’s fictional demon character in The Great Divorce, and neither work is part of the Narnia series.