What was the original title of C.S. Lewis’s book later published as Mere Christianity?

C.S. Lewis’s book later published as Mere Christianity originally appeared as Broadcast Talks.

Lewis delivered the talks over BBC radio during World War II. The first series was broadcast in 1941, followed by additional series in 1942 and 1944. He aimed to explain shared Christian beliefs in accessible language rather than defend one particular denomination.

The talks were revised and collected in book form. Broadcast Talks was published in 1942, while later editions incorporated material from Christian Behaviour and Beyond Personality. The combined work became Mere Christianity, a title that Lewis used for the expanded 1952 volume.

The title “mere Christianity” refers to the core beliefs shared across historic Christian traditions. It does not mean a vague or minimal personal philosophy. Readers sometimes remember Christian Behaviour or Beyond Personality as the original title, but those were separate sections or related collections within the development of the final book.