Which C.S. Lewis book uses letters from the senior demon Screwtape to advise his nephew Wormwood?

The Screwtape Letters is the C.S. Lewis book in which the senior demon Screwtape advises his nephew Wormwood. Lewis wrote the work as a series of fictional letters offering a satirical view of temptation.

Screwtape addresses Wormwood as the junior tempter responsible for influencing a human “patient.” The demonic perspective lets Lewis reverse ordinary moral language: spiritual failure is treated as success, while goodness appears as a threat. This reversal creates the book’s comedy and sharpens its religious criticism.

The letters were first published in book form in 1942, after appearing in the Anglican newspaper The Guardian. Lewis later found the process of imagining demonic advice uncomfortable and did not produce a similar sequel. Readers sometimes confuse the book’s correspondence format with ordinary theological instruction, but it is deliberately fictional and satirical.