What was the title of C.S. Lewis’s 1942 book written as letters from a senior tempter?

C.S. Lewis’s 1942 book written as letters from a senior tempter is The Screwtape Letters.

The book consists of correspondence from Screwtape, an experienced demon, to his inexperienced nephew Wormwood. Their letters discuss how to undermine a human subject’s moral and spiritual life, using reversed advice to satirize temptation and self-deception.

Lewis first published the work in serialized form in the Anglican newspaper The Guardian in 1941. The collected book followed in 1942. Its unusual perspective lets Lewis explore human habits such as distraction, vanity, resentment, and spiritual complacency without presenting the advice as genuine moral instruction.

Readers sometimes group the book with Lewis’s direct apologetic works, including Mere Christianity. Its form is different: it is a fictional epistolary satire, and the narrator’s demonic viewpoint is deliberately ironic.