- Creator Backlash: A relatively mild example. Lewis said in the foreword of later editions that while Screwtape was one of the easiest things he ever wrote, it was also the least enjoyable. As he put it, it caused a kind of moral cramp, forcing himself into a demonic mindset. He also resented it for not being something he felt he wasn't skilled enough to write - Screwtape's advice balanced by angelic advice from Heaven. And he was rather annoyed that his later more serious books were marketed as "By the author of The Screwtape Letters". For these reasons, he never wrote a true sequel, though he did write a toast (a scathing criticism of the American educational system at the time and its resulting Tall Poppy Syndrome) in Screwtape's voice.
- Follow the Leader: Several Christian writers have copied Lewis's conceit of an Epistolary Novel by The Devil to deliver their own Author Tracts, with examples including Screwtape Writes Again by Walter Martin, To My Dear Slimeball by Rich Miller, and Lord Foulgrin's Letters and its sequel The Ishbane Conspiracy by Randy Alcorn. Let's just say that none of them has come anywhere close to the success of the original.
- Magnum Opus Dissonance: Alongside The Chronicles of Narnia, The Screwtape Letters is one of Lewis's most notable works, though he found it actively unpleasant to write. Till We Have Faces was Lewis's favorite of his own works, and he once said Perelandra was worth ten Screwtapes.
- Science Marches On: Screwtape mentions that "the majority of the human race dies in infancy". Thanks to modern medicine, it's not as much the case now as it was in the 1940s.
- What Could Have Been:
- In the original draft of the introduction, the letters were retrieved and translated from Old Solar by Ransom, the protagonist of The Space Trilogy.
- Pr. Lewis originally planned a P.O.V. Sequel, featuring Screwtape's Good Counterpart (mostly believed to be the Archangel Gabriel) giving advice to the patient's guardian angel, but never actually followed through on it. Some of that may have been reworked into The Great Divorce, where saintly humans try to persuade less-blessed souls to give up their vices and come with them to Heaven.
- Write What You Know: In the preface to the second edition, Lewis mentions that some people said he must have studied moral theology in great detail to be able to write so accurately about the nature of sin and temptation. He replied that this overlooked the actual source: He could learn all he needed about sin and temptation from his own heart.
Trivia / The Screwtape Letters