Lewis Wolpert is Emeritus Professor of Biology as Applied to Medicine in the Department of Cell and Developmental Biology at University College, London. His research interests are in the mechanisms involved in the development of the embryo. He was made a Fellow of the Royal Society in 1980 and a Fellow of the Royal Society of Literature in 1999. His books include The Triumph of the Embryo (OUP, 1991), Malignant Sadness - The Anatomy of Depression (Faber, 1999), Principles of Development, of which he is principal author, (4th edition, OUP 2011), and How We live, and Why We Die - the secret life of cells (Faber, 2009). He is also co-chief editor of the Journal of Theoretical Biology.