What title did C.S. Lewis give the 1940s radio talks later collected as Mere Christianity?

C.S. Lewis called the first set of radio talks later collected as Mere Christianity Broadcast Talks.

Lewis delivered the BBC radio talks during the Second World War. The first series was broadcast in 1941 under the title Broadcast Talks. A second series followed as Christian Behaviour in 1942, and a third as Beyond Personality in 1944. The material was revised and brought together in book form as Mere Christianity in 1952.

The talks were intended for a broad British audience rather than a specialist theological readership. Lewis explained shared Christian beliefs, moral reasoning, and the Christian understanding of God, Christ, and human transformation. The final book’s title refers to the common or central beliefs of Christianity, not to a separate denomination.

The earlier titles matter because Mere Christianity was not the original broadcast title. Some references use The Case for Christianity for an American edition of part of the material, which can make the publication history appear more complicated than it is.