Screwtape represents the senior tempter in C.S. Lewis’s The Screwtape Letters. The book is presented as a collection of letters from Screwtape to his inexperienced nephew, Wormwood.
In the letters, Screwtape gives advice about tempting a human subject and undermining that person’s spiritual life. Lewis uses the fictional demon’s professional, bureaucratic voice to satirize human weakness, self-deception, pride, distraction, and shallow religious habits.
Wormwood is the junior tempter receiving the correspondence, so he is a frequent source of confusion in this question. Screwtape, not Wormwood, is the title character and the senior adviser. The book was first published in book form in 1942 after appearing in installments in the Anglican newspaper The Guardian.
Lewis’s inversion of perspective is central to the work: readers are meant to recognize that the demons’ strategic language exposes ordinary human behavior. The result is both a theological satire and a study of moral psychology.