Stephen Sackur speaks to Daniel Dennett, a philosopher who applies Darwinian evolutionary theory not just to species, but to ideas and religious beliefs. He believes religion has outlived its usefulness, hampers rational thought and damages our species. Along with Richard Dawkins and the late Christopher Hitchens, Dennett is seen as a founding father of the new atheism. But do humans want to live in a world where atheism rules and religion is dead?