Screwtape is the senior demon who writes to a junior tempter in C.S. Lewis’s The Screwtape Letters.
The book was published in 1942 and consists of letters from Screwtape to his inexperienced nephew, Wormwood. Screwtape offers strategic advice about tempting a human patient, while Lewis presents the advice ironically so that readers can recognize the moral and spiritual errors being recommended.
Lewis wrote the letters during the Second World War, and the work first appeared in serial form in the Anglican newspaper The Guardian. The imagined viewpoint allowed him to discuss pride, distraction, resentment, prayer, and habit by showing how a demon might exploit them. Lewis later found the project unpleasant to sustain because he had to keep writing from a demonic perspective.
Screwtape is not the junior tempter’s name: Wormwood is the nephew receiving the letters. The distinction matters because the book’s title refers to the letter writer, while the narrative mainly describes the unseen human patient and his spiritual development.