I'll take this opportunity to mention one unrelated letter he wrote, quoted not in his biography but self-deprecatingly (and, obviously, memorably) by its recipient, California pastor William Steuart McBirnie, on his TV show three decades ago. McBirnie revealed he had written to Lewis many years earlier requesting clarification, "Exactly how does Christianity save?" He gave CS Lewis' reply in full, which I believe I've reproduced here word-for-word: "Christianity does NOT save. Christ saves."
Cuts to the chase. Reminds me of something else he said. Asked something like, do we have souls, he responded in words to the effect, "No, we are souls. We have bodies."
Or was that Chesterton? No, I think it was Lewis.