Which C.S. Lewis book is an epistolary satire written as letters from a senior demon?

The Screwtape Letters is an epistolary satire written as letters from the senior demon Screwtape. C.S. Lewis published the book in 1942, during the Second World War.

Screwtape writes advice to his inexperienced nephew Wormwood, who is attempting to tempt a human being. Because the advice is presented from a demon’s perspective, Lewis reverses ordinary moral language: spiritual growth appears as a threat, while distraction, pride, and self-deception are treated as useful tools.

The book’s letter format lets Lewis examine human habits one at a time. Its targets include resentment, vanity, social pressure, romantic confusion, and the tendency to substitute vague feelings for disciplined thought. The satire depends on readers recognizing that the demons’ goals are the opposite of healthy moral life.

The name can be confused with Screwtape himself, but the title refers to the entire collection of letters. Wormwood is the junior demon and recipient, while Screwtape is the experienced adviser.