Sir Paul Nurse was awarded the Nobel Prize in Physiology or Medicine in 2001, and until 30th November 2015 was the President of the Royal Society. Three of the great ideas of biology are the gene theory, the theory of evolution by natural selection, and the proposal that the cell is the fundamental unit of all life. When considering the question of ‘what is life?’ these ideas come together. A fourth idea is that the organisation of chemistry within the cell provides explanations for life’s phenomena. A new idea is the central role that information management plays in generating biological organisation. Sir Paul Nurse discusses how these great ideas have influenced and changed the way we think of science today.