Leslie Valiant is currently T. Jefferson Coolidge Professor of Computer Science and Applied Mathematics at Harvard University. His work has ranged over several areas of computer science, particularly complexity theory, machine learning, and parallel computation. He also has interests in computational neuroscience, evolution and artificial intelligence. He is the author of two books, “Circuits of the Mind”, which describes a computational approach to understanding the brain, and “Probably Approximately Correct” which discusses the centrality of learning to biology and evolution. He was educated at King’s College, Cambridge; Imperial College, London; and at Warwick University where he received his Ph.D.. Before coming to Harvard he had taught at Carnegie Mellon University, Leeds University, and the University of Edinburgh. He is a Fellow of the Royal Society and a member of the National Academy of Sciences. He received the Nevanlinna Prize at the International Congress of Mathematicians in 1986, and the 2010 Turing Award.