This was not quite what I was expecting. Lewis made that clear in his introduction, so I was aware once I started to read that I was getting something else. I was expecting a treatise on methods of coping with pain - emotional, physical, acute, chronic - with some reference to Christianity as Lewis was a Christian and wrote from that standpoint.
This is a book that seeks to answer the question as to why pain exists, given the Christian notion of an all-powerful god that is goodness personified. As I'm not Christian (though if anyone were to persuade me, it would be Lewis) I had to suspend disbelief while reading this book. It is not possible to simply wiggle a little and make what Lewis says fit your worldview. One has to suspend disbelief, read the totality of what he says and then see if what he says makes sense with whatever it is that you believe.
His argument is interesting and it's certainly one that I've never before considered. I'm not even going to try to summarise what he says. Mostly because he says it so much better and more clearly than I ever could and partly because I'm still letting it settle into my mind and find its place there.
I can only recommend this to Christians, or people who wonder what a Christian argument explaining pain and suffering is. If you're not interested in that, this isn't the book for you.