The Problem of Pain
In this book Lewis makes a philosophical analysis of suffering discussing why it is possible. It is not a devotional book, but one of pure reflection. Starting from a thorny paradox (how can there be suffering in the world if God is good and all-powerful?), Lewis makes his argument, passing through various Christian doctrines: the doctrine of grace, forgiveness, repentance. It discusses the possible natures of Heaven and Hell and their relationship to our life on Earth, making it clear just how suffering is an inherent aspect of life in a material universe.
In the end, he comes to the frightening conclusion that human suffering, despite being the result of a fall (Adam's sin, whether understood as an allegory or an actual fact), is also God's means of showing himself to men. It all depends on what we decide to turn it into: a curse or an opportunity for growth and courage.
From Lewis's style of argument came the idea of presenting the book as a clinical examination of suffering (which in fact it is). Again, the central idea underwent little change. The image is that of an x-ray of the hand of Christ nailed to the cross (an extreme example of suffering, particularly suitable for a book with a Christian basis), seeking with this shocking image to awaken the reader to the discussion that is about to begin.
On the back cover, the background image is that of the damned in Hell, writhing in pain, while the image in the center (the one that is repeated in chapter openings) shows a man carrying a heavy block of stone, symbolizing suffering as one of the inevitable burdens of our humanity. A burden, however, that can be carried.