What We Believe But Cannot Prove: Today's Leading Thinkers on Science in the Age of Certainty is a non-fiction book edited by literary agent John Brockman with an introduction by novelist Ian McEwan and published by Harper Perennial. The book consists of various responses to a question posed by the Edge Foundation, with answers as short as one sentence or as long as a few pages. Among the 107 published contributors are such notable scientists and philosophers as Richard Dawkins, Daniel C.