His fellow Inkling, Owen Barfield was a student of Rudolf Steiner. He had other Inklings who would into Tarrot, Kabbalah, and more. Lewis packed a lot more into his books than you know. The Jesuits are also responsible for a major portion of the foundation of Dr Gilbert’s work. Incase you think about diving back into his books for fun. The Space Trilogy are some of my favorites but I’ve yet to read a Lewis book that wasn’t great.