John Brockman, the New York literary agent and science writer, had an artist friend, James Byars, who had a grand idea. It was ‘to gather the 100 most brilliant minds in the world together in a room, lock them in and have them ask each other the questions they were asking themselves’. The result, he supposed, would be a ‘synthesis of all thought’. He drew up his list of minds and telephoned them all. Seventy per cent of them proved their brilliance by hanging up on him. Brockman, undeterred, carried on where Byars had left off. He started a website, Edge, where he invited fellow-thinkers to answer the question, ‘What do you believe is true, even though you cannot prove it?’ The response, says Brockman, was sensational; a speaker on BBC Radio 4 called his question ‘fantastically stimulating.