What was the title of C.S. Lewis’s 1940 book defending Christianity and addressing human suffering?

The Problem of Pain is C.S. Lewis’s 1940 book defending Christianity while examining why a powerful and loving God might permit suffering. It addresses topics including divine omnipotence, human free will, hell, animal pain, and the meaning of goodness.

Lewis wrote the book as a work of Christian apologetics, aiming to present arguments for Christian belief rather than a personal memoir of bereavement. Its approach is therefore different from A Grief Observed, which he wrote after Joy Davidman’s death and published in 1961.

The Problem of Pain is also distinct from Mere Christianity. Mere Christianity developed from wartime radio talks broadcast during the 1940s, while The Problem of Pain began as a separate book-length argument. The two works are often grouped together because both explain Lewis’s Christian ideas to general readers.