Our brain is the source of everything that makes us human: language, creativity, rationality, emotion, communication, culture, politics. The neurosciences have given us, in recent decades, fundamental new insights into how the brain works and what that means for how we see ourselves as individuals and as communities. Now - with the help of new advances in nanotechnology - brain science proposes to go further: to study its molecular foundations, to repair brain functions, to create mind-machine interfaces, and to enhance human mental capacities in radical ways. This book explores the convergence of these two revolutionary scientific fields and the implications of this convergence for the future of human societies. In the process, the book offers a significant new approach to technology assessment, one which operates in real-time, alongside the innovation process, to inform the ways in which new fields of science and technology emerge in, get shaped by, and help shape human societies.