This was, in my opinion, the hardest read by CS Lewis that I have experienced thus far. Maybe it was because I was slightly preoccupied while listening to it (audiobook). The message is a good one, though. I believe it has much to do like an exposition on the first two chapters of Mere Christianity, but taken from a different perspective. By the end I understood the point Lewis was trying to make, and did enjoy it, but this one definitely made me work harder to get to the end.