David Wootton is Anniversary Professor of History at the University of York. His previous books include Paolo Sarpi (1983), Bad Medicine (2006) and Galileo (2010). He has given the Raleigh Lecture at the British Academy (2008), the Carlyle Lectures at Oxford (2014) and the Benedict Lectures at Boston (2014), and a Beller Lecture to the American Physical Society (2016). His next book will be on the pursuit of happiness.