Book excerpt: Great leaps forward in scientific understanding have, throughout history, engendered similar leaps forward in how we understand ourselves. Now, the new hybrid disciplines of evolutionary biology and social physics are making the next leap possible -- and fundamentally altering our notions of individual identity. If identity is a fact not derived from within the individual, but conferred on an individual by a group, or network, a host of assumptions about how governments work, how conflicts arise and are resolved, and how societies can be coaxed toward good are overturned. John Clippinger brilliantly illuminates how the Enlightenment itself -- the high point of individual assertiveness -- was a product not just of a few moments of individual inspiration and creativity, but rather of a societal shift that allowed innovation and creativity to flourish. Michelangelo owes quite as much to the circumstances of the Renaissance as the Renaissance does to the work of Michelangelo. Now, the digitalization of society, which affects all of us already, allows new insight into these questions: What does it require for societies, organizations and individuals, to thrive? Who decides who you are? How can happiness be shared and spread? Who can you trust?