What is the title of C.S. Lewis’s 1942 Christian apologetics book featuring a senior tempter?

The Screwtape Letters is C.S. Lewis’s 1942 Christian apologetics book featuring a senior tempter. It presents a fictional series of letters from Screwtape, an experienced demon, to his nephew Wormwood.

Screwtape advises Wormwood on how to influence a human subject away from Christian belief and moral action. Lewis reverses the expected viewpoint: readers hear the demons discuss temptation, distraction, pride, fear, and spiritual complacency as professional techniques.

The work began as a series published in the Anglican newspaper The Guardian. Lewis later collected the pieces as a book. Its epistolary structure gives the satire a distinctive voice and allows Lewis to examine everyday habits rather than only dramatic acts of wrongdoing.

The book is often grouped with Lewis’s other apologetic works, including Mere Christianity and The Problem of Pain. Unlike those books, The Screwtape Letters communicates much of its argument indirectly through irony and the advice of its fictional demons.