Which C.S. Lewis work presents a fictional debate between demons about tempting a human?

The C.S. Lewis work presenting a fictional debate between demons about tempting a human is The Screwtape Letters.

The book consists of letters from Screwtape, an experienced demon, to his inexperienced nephew Wormwood. Screwtape gives advice about how to influence a human known as “the Patient,” while the reader learns about temptation through the demons’ distorted perspective.

Lewis originally published the letters serially in the Anglican newspaper The Guardian during 1941. The letters were later collected as a book. Their satirical method lets Lewis discuss pride, distraction, resentment, social pressure, prayer, and moral choice without presenting the advice as reliable wisdom.

The work is often mistaken for a straightforward treatise on demonology. It is better understood as religious satire and moral commentary. Lewis deliberately gives the demons bureaucratic and professional language, making ordinary temptations appear like procedures in an infernal office. He later found the project emotionally unpleasant to continue, because maintaining the demonic viewpoint required sustained attention to the subject. The book remains one of his most widely read nonfiction works.