What We Believe But Cannot Prove: Today's Leading Thinkers on Science in the Age of Certainty is a non-fiction book published by Harper Perennial and edited by literary agent John Brockman that includes an introduction by novelist Ian McEwan.

[1] Among the 107 published contributors are scientists and philosophers such as Richard Dawkins, Daniel C. Dennett, Jared Diamond, Rebecca Goldstein, Steven Pinker, Sir Martin Rees, and Craig Venter; as well as convicted sex offender Jeffrey Epstein.

[3][4] Each year, the Edge Foundation poses a question on its website to members of the "third culture", defined by Brockman as "those scientists and other thinkers...who, through their work and expository writing, are taking the place of the traditional intellectual in rendering visible the deeper meanings of our lives, redefining who and what we are".

[9] What We Believe But Cannot Prove received positive reviews from The Boston Globe, which printed that: "taken as a whole, this little compendium of essays will send you careening from mathematics to economics to the moral progress of the human race, and it is marvelous to watch this muddle of disciplines overlap".

[12][13] The Daily Telegraph praised the book as "refreshing" and "intriguing and unexpected", noting that "[b]y unleashing scientists from the rigours of the established method we gain fascinating glimpses into the future directions of arcane disciplines few fully understand".