In 2010 the Royal Society celebrated its 350th anniversary. To mark this event the BBC designated 2010 as a “year of science” and commissioned several special programs with scientific themes. It was also thought timely for the Reith Lectures that year to have a scientific theme, and I was invited to give them by Mark Damazer, controller of BBC Radio 4. Mark’s persuasive powers overcame my diffidence and my unease about the format; I’m grateful for the advice and encouragement he offered me at every stage. Three of my Royal Society colleagues, Peter Collins, Peter Cotgreave, and James Wilsdon, made helpful comments on the script. I’m grateful also to Sue Ellis, Kirsten Lass, Martin Redfern, and their colleagues at the BBC for editorial suggestions, and for ensuring that the production and presentation of the lectures in four different locations went off smoothly. And I’m indebted to Sue Lawley for the zest and professionalism with which she introduced each lecture and moderated the lively discussions afterward.
Andrew Franklin encouraged me to prepare this expanded text; I am grateful to him, and to Penny Daniel, Susanne Hillen, and Rukhsana Yasmin for editorial advice and support at Profile Books, and to Angela von der Lippe and Laura Romain at Norton and Carol Rose, copy editor, for help with the US edition.