Professor Steven Pinker delivers the Gifford Lecture series entitled "The Better Angels of Our Nature: A History of Violence and Humanity". Contrary to the popular impression view that we are living in extraordinarily violent times, rates of violence at all scales have been in decline over the course of history. This lecture explores how this decline could have happened despite the existence of a constant human nature. Steven Pinker is Harvard College Professor and Johnstone Family Professor in the Department of Psychology at Harvard University. He conducts research on language and cognition, which has won prizes from the National Academy of Sciences, the Royal Institution of Great Britain, the American Psychological Association, and the Cognitive Neuroscience Society. Recorded on Wednesday 29 May 2013 at McEwan Hall, the University of Edinburgh.