Which C.S. Lewis book features the demonic tutor Screwtape?

The C.S. Lewis book featuring the demonic tutor Screwtape is The Screwtape Letters.

The book was published in 1942 and is presented as a series of letters from Screwtape, a senior demon, to his inexperienced nephew Wormwood. Screwtape gives advice about tempting a human patient, while the reader must recognize that the advice is deliberately morally distorted. Lewis uses irony to discuss pride, distraction, fear, social pressure, and spiritual self-deception.

Lewis devised the work as a satirical inversion of a spiritual advice manual. The format lets him explore ordinary habits rather than relying on dramatic supernatural events. The “patient” is never given a personal name, which makes the situations broadly applicable to readers.

The book is sometimes confused with Mere Christianity, another Lewis work that developed from radio talks and presents direct Christian arguments. The Screwtape Letters instead uses a fictional correspondence between demons. Its unusual viewpoint is the central literary device, not evidence that Lewis endorsed the demons’ claims.