What name did C.S. Lewis give his 1940 book of letters from a demon?

C.S. Lewis gave his 1940 book of fictional demonic correspondence the title The Screwtape Letters.

The book consists of letters from Screwtape, an experienced demon, to his inexperienced nephew Wormwood. Screwtape offers advice about tempting a human being, whom he calls “the Patient.” Lewis uses the imagined advice to examine ordinary moral weaknesses, self-deception, distraction, pride, and spiritual complacency.

The letters first appeared in the Anglican newspaper The Guardian, beginning in 1941. They were later collected and published as a book. Lewis’s unusual viewpoint lets him satirize demonic thinking while presenting a distinctly Christian account of temptation and moral choice.

Readers sometimes confuse this work with The Great Divorce, another Lewis book with supernatural imagery. The Great Divorce is an allegorical tale about a bus journey from a grey version of the afterlife, while The Screwtape Letters is structured as correspondence between demons.