What title was given to C.S. Lewis’s BBC radio talks later collected as Mere Christianity?

C.S. Lewis’s BBC radio talks later collected as Mere Christianity were first published as The Case for Christianity.

Lewis delivered the talks during the Second World War, beginning in 1941, when the BBC asked him to address a broad public audience. He was not presenting a detailed denominational system; instead, he discussed basic Christian ideas in accessible language, beginning with moral law and moving toward Christian belief.

The talks were issued in stages. Broadcast Talks appeared in 1942, Christian Behaviour followed in 1943, and Beyond Personality was published in 1944. The material was later revised and combined in the 1952 book Mere Christianity.

The title The Case for Christianity is therefore associated with the first collected section, not the final overall title of the work. Readers sometimes assume that Mere Christianity was the original broadcast title, but it was the later name for the combined volume. The book became one of Lewis’s best-known works of Christian apologetics.