What name did C.S. Lewis use for the BBC talks that became Mere Christianity?

C.S. Lewis presented the material that became Mere Christianity as BBC broadcast talks.

During the Second World War, Lewis delivered a series of short radio talks for the BBC. The broadcasts were intended for a broad public audience and explained basic Christian ideas in accessible language rather than presenting a detailed defense of one particular denomination.

The talks were later revised and collected in book form. Mere Christianity was published in 1952, bringing together material from the earlier broadcasts and related writings. The title refers to the central beliefs shared across historic Christian traditions.

Lewis is sometimes described as having preached sermons on the radio, but the broadcasts were talks rather than church sermons. The distinction matters because the series was designed for listeners across Britain, including many who had little formal theological training. Its conversational style helped make the book one of Lewis’s most widely read works.