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".[5]
The essays cover a broad range of topics, including evolution, the workings of the human mind, and science itself. A common focus is the issue of extra-terrestrial life and whether humanity has a supranatural element beyond flesh and blood.[6] Among the more esoteric topics is the question of cockroach consciousness.[7]
A pervasive theme, according to Publishers Weekly, is the discomfort responders felt in professing unproven beliefs, which Publishers Weekly described as "an interesting reflection of the state of science".[8] The question inspired implicit or explicit reflection in a number of responders about the scientific method's reliance on observable, empirical and measurable evidence, with a good many of what The Observer points out as largely American responders defending against "the return to an age of uncertainty in which creationism and intelligent design hold sway in the public mind".[6] "What's really at stake here", Wired said in its review, "is the nature of 'proof' itself".[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".[10] The Skeptical Inquirer stated that the book "offers an impressive array of insights and challenges that will surely delight curious readers, generalists, and specialists alike".[11]
Science News and The Guardian described the book respectively as "a tantalizing glimpse into the future of human inquiry" and "[s]scientific pipedreams at their very best".[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".[7]
While still generally positive, some reviewers criticized certain aspects of the book, including redundancy and tone. The Observer described the essays as "compelling and repetitive by turns".[6] Publishers Weekly referred to the collection as "stimulating", but found it "unfortunate that the tone of most contributions isn't livelier and that there aren't explanations of some of the more esoteric concepts discussed", limitations which would "keep these adroit musings from finding a wider audience."[8]
Krause, Kenneth. (January 5, 2007) "Intellectual and creative magnificence.(What We Believe But Cannot Prove: Today's Leading Thinkers in the Age of Uncertainty)(Book review)" (abstract) The Skeptical Inquirer, March 1, 2007. Full article hosted by redorbit.com.