Which C.S. Lewis work is a series of letters from a senior demon to a junior tempter?

The Screwtape Letters is a series of letters from a senior demon to a junior tempter.

Published in book form in 1942, the work consists of advice written by Screwtape to his inexperienced nephew Wormwood. Screwtape’s assignment is to guide Wormwood in tempting a human subject away from Christian faith and moral seriousness.

Lewis uses an inverted viewpoint: the demons describe virtue as a danger and temptation as a professional success. That reversal allows him to examine pride, distraction, resentment, social pressure, and self-deception without presenting the advice as sound moral guidance.

The letters first appeared in the Anglican newspaper The Guardian. Lewis later dedicated the book to his friend J.R.R. Tolkien, although Tolkien did not enjoy the dedication. Readers sometimes confuse the book with Lewis’s direct apologetic works, but its fictional epistolary form and demonic narrators make it distinctive.