C.S. Lewis began broadcasting his wartime talks on Christianity in 1941. The talks were delivered for the BBC during the Second World War and later became the foundation of Mere Christianity.
The BBC invited Lewis to speak about Christian belief to a broad public audience. His broadcasts used direct, conversational language rather than academic terminology, making difficult ideas accessible to listeners facing the uncertainty and strain of wartime Britain. He continued the series in later years, with talks broadcast in 1942 and 1944 as well.
The original broadcasts were not titled Mere Christianity. Lewis revised and expanded them for publication, first in separate pamphlets and later in the 1952 book Mere Christianity. The book’s title therefore refers to the published structure, while 1941 identifies the beginning of the radio project.
These broadcasts helped make Lewis a nationally known religious speaker. They also illustrate the difference between a work’s first public form and the later book associated with it, a distinction that frequently causes date-based trivia errors.