Screwtape is the senior demon and narrator of C.S. Lewis's The Screwtape Letters.
The book, published in 1942, consists of letters from Screwtape to his junior nephew Wormwood. Screwtape works as an experienced tempter and offers advice on how to influence a human patient. Lewis presents the advice ironically, so the demons' language exposes the destructive habits they are trying to encourage.
Lewis wrote the work as a satirical Christian apologetic text. Its epistolary form lets him examine pride, distraction, resentment, social pressure, and self-deception from an inverted perspective. The reader is expected to recognize the moral errors hidden inside the demons' apparently professional instructions.
Wormwood is the younger demon receiving the letters, not the authorial narrator. Screwtape is also distinct from Satan, who is not the book's letter-writing voice. The unusual viewpoint is a major reason the work remains one of Lewis's most recognizable titles.