Sam Leith

He does not know how much he does not know

There’s a wonderful story in this book, told by the biologist Lewis Wolpert, about a vistor to the office of the physicist Niels Bohr. The visitor, a fellow scientist, was astonished to see a horseshoe nailed above the Nobel laureate’s desk. ‘Surely you don’t believe that horseshoe will bring you luck?’ he said. ‘I believe no such thing, my good friend,’ replied Bohr. ‘Not at all. I am scarcely likely to believe in such foolish nonsense. However, I am told that a horseshoe will bring you good luck whether you believe in it or not.’

• From magazine issue: 29 September 2007