Lewis had a lot to say about atheists and atheism, mentioning the topic at least seventy-eight times in at least thirty books and essays. Having been an atheist himself, he understood Christianity from—as he put it—the outside. He held many of the same positions that atheists did in the 1910s and 1920s and for many of the same reasons that still influence people today. Although he did not compose any sort of systematic description, definition, or formal reaction to atheism, we can glean a great deal from his writings. Perhaps most important of all, Lewis knew quite a few atheists but avoided making generalizations about them. He knew how different they were from one another and that people become atheists for a wide variety of reasons.
Heck, Joel D.
"C. S. Lewis on Atheism,"
Sehnsucht: The C. S. Lewis Journal: Vol. 11
, Article 7.
Available at: https://digitalcommons.georgefox.edu/cslewisjournal/vol11/iss1/7