What do you believe is true even though you cannot prove it?. This was the question posed by John Brockman to a group of leading scientists and thinkers via his Edge.org website. The subsequent answers created a media storm and prompted a fiery debate about all aspects of science, technology and even the nature of proof. What We Believe But Cannot Prove brings together the very best answers from the most eminent contributors. Here is Ian McEwan on the absence of an afterlife; Richard Dawkins on the relationship between design and evolution; and Jared Diamond on when humans first reached the Americas. Other contributions from luminaries like Steven Pinker, John Horgan and Martin Rees span the whole range of scientific endeavour and human experience, from the future of computing to the origins of intelligence; from insights into childhood behaviour to cutting-edge cosmology. Thought-provoking and hugely compelling, this collection is both a fascinating insight into the instinctive beliefs of some of the most brilliant minds alive today - and an invitation to answer the question yourself...