C.S. Lewis’s most popular non-Narnia novel is a delicious, perceptive treatise on the weaknesses of human nature. Here are 12 little-known facts about The Screwtape Letters, its development, and its enduring impact.    

1. It Took Lewis A Little Over Six Months to Write All 31 Letters.

In July 1940, Lewis came up with the idea of a senior demon named Screwtape mailing trade secrets and frank pointers to his greenhorn nephew, Wormwood, who has been charged with corrupting a human soul. Inspired, the author worked at breakneck speed, frequently knocking out an entire letter in one sit-down session.

2. Originally, These Dispatches Ran as a Serial.

Having already submitted material to a now-defunct Anglican gazette called The Guardian, Lewis was in good standing with its editor, who released the first “Screwtape Letter” on May 2, 1941. Every week, another hellish correspondence would appear, until the last one hit the stands on November 28. Readers devoured them en masse, and before long, publisher Geoffrey Bles converted Lewis’ series into a book

3. The Newspaper Proceeds Helped a Charitable Cause.  

The Guardian offered Lewis two pounds per letter. Refusing payment, he insisted that a fund dedicated to the widows of Church of England clergymen receive this money instead.

4. One of the Human Characters Was Probably Based on a Woman Lewis Lived With.  

Lewis wasn’t the sort who would go back on a promise made to a fallen friend. In WWI, he and a comrade named Paddy Moore agreed that if either man should perish, the other would take care of his surviving parent (both had already lost one—Lewis’s mother succumbed to cancer in 1908). Paddy ultimately died on the French front, leaving Janie King Moore behind. After the war, Lewis moved in with and tended to her.    

The overbearing Mrs. Moore could be a very difficult person. Lewis’ older brother, Warren, was disgusted by her manipulative, “insincere” personality. “She … interfered constantly with his work,” Warren recalled, “and imposed upon him a heavy burden of minor domestic tasks.” In The Screwtape Letters, Lewis’ fiction clearly borrowed from his reality. Wormwood’s mortal “client” has an exacting mother who’s described as “a positive terror to hostesses and servants.” Almost every C.S. Lewis biographer under the sun believes that she was also, in fact, a caricature of Mrs. Moore. 

5. Some Readers Didn’t Understand That the Letters Were Satirical.  

During their run in The Guardian, one angry clergyman canceled his subscription. Evidently, this fellow mistook Screwtape for an actual (and terrible) theologian doling out sincere spiritual tips. The outraged church official wrote the editor to complain that “much of the advice given in these letters … [seems] not only erroneous but positively diabolical.”

6. The Author Didn’t Enjoy Writing Them.

“Of all my books,” Lewis admitted in a 1963 interview, “there was only one I did not take pleasure in writing.” He found The Screwtape Letters “dry and gritty going. At the time, I was thinking of objections to the Christian life and decided to put them in the form ‘That’s what the devil would say.’ But making goods ‘bad’ and bads ‘good’ gets to be fatiguing.” 

7. Their Success Prompted Lewis to Hire His Brother as an Aide.  

Screwtape’s newspaper premiere triggered a typhoon of fan mail. Since Lewis couldn’t keep pace with it all, the novelist asked Warren if he’d consider becoming his paid personal assistant. This turned out to be an excellent job for Warren, whose responses to these admirers were so clever and so well-composed that they could easily pass for his sibling’s handiwork. 

8. The Book Version Is Dedicated to J.R.R. Tolkien, Who Didn’t Appreciate the Gesture.

Published in 1942, it turned into a runaway bestseller destined for eight reprints before the year’s end. Crack open any copy today, and you’ll find “To J.R.R. Tolkien” inside. But truth be told, Lewis’ longtime friend found the story disturbing. Plus, Tolkien knew just how little his colleague personally thought of it. It should come as no surprise, then, that he was less than thrilled with this particular shout-out.

9. Lewis Considered Writing a Companion Novel from An Angel’s Perspective.

At first, the concept of some new messages detailing “archangelical advice to the patient’s guardian angel” delighted Lewis. But his standards were too high and that project never took off. “Mere advice would be no good,” Lewis lamented, “every sentence would have to smell of Heaven.”

10. A Brief Sequel Appeared in The Saturday Evening Post. 

Lewis never penned another devilish letter, but when asked to do so by the Post, he did churn out a speech on behalf of his most sinister creation. In 1959's “Screwtape Proposes a Toast,” the demon gives a mealtime speech at the Tempter's Training College for Young Devils somewhere in Hell. Topics addressed include democracy, education, and—of course—religion. 

11. Multiple Authors Have Written Unofficial Follow-Ups.

A certain fiend opines on everything from gossip to pornography in Screwtape Writes Again (1975) by Martin Walter. Then there’s The Screwtape Email (2006): a self-explanatory postscript courtesy of Arthur H. Williams Jr. But perhaps the best-regarded of all is The Snakebite Letters: Devilishly Devious Secrets for Subverting Society as Taught in Tempter’s Training School  (1998) by Catholic philosopher Peter Kreeft. “I’m sure Lewis wanted such ‘plagiarisms,’” proclaims Kreeft’s introduction. “The Screwtape Letters invented a new genre, a new species; all I’m doing is breeding another specimen.” 

12. Calvin and Hobbes Included a Recurring Player Named After Screwtape’s Nephew.

Bill Watterson has acknowledged that Miss Wormwood (Calvin’s long-suffering teacher) was named for the naïve tempter, “as a few readers have guessed.” Lewis himself probably borrowed the moniker from a Biblical star mentioned in Revelations 8:11.