Which book by C.S. Lewis collects broadcasts first made for the BBC during World War II?

Mere Christianity collects C.S. Lewis’s BBC broadcasts from the early 1940s. The talks were delivered during World War II and later revised and published as a book in 1952.

Lewis originally presented the broadcasts as short explanations of Christian belief for a broad audience. He aimed to describe ideas shared by major Christian traditions rather than defend the distinctive doctrines of one denomination.

The book is organized into four parts: right and wrong as a clue to the meaning of the universe, Christian belief, Christian behaviour, and personality or the doctrine of the Trinity. Its title refers to what Lewis called “mere” or basic Christianity.

The work is sometimes mistaken for a transcript of a single lecture series published unchanged. In fact, Lewis revised the broadcast material for print, and the book became one of his most influential works of Christian apologetics.