Brain science matters. The strange computational material in our skulls is the perceptual machinery by which we navigate the world, the stuff from which decisions arise, the material from which imagination is forged. Our dreams and our waking lives emerge from its billions of zapping cells. A better understanding of the brain sheds light on what we take to be real in our personal relationships and what we take to be necessary in our social policy: how we fight, why we love, what we accept as true, how we should educate, how we can craft better social policy, and how to design our bodies for the centuries to come. In the brain’s microscopically small circuitry is etched the history and future of our species.