Longer lives are, at once, among the most remarkable achievements in all of human history and the greatest challenges of the 21st century. Whereas most discussions about aging societies are premised on the assumption that older people are frail and infirm, our premise is that problems of older people demand solutions so that the substantial increase in life expectancy can ultimately benefit individuals and societies. The mission of the Stanford Center on Longevity is to accelerate and implement scientific discoveries, technological advances, behavioral practices, and social norms so that century-long lives are healthy and rewarding. We are a center on longevity, not old age because building a world where the majority of people thrive in old age requires attention to the entire life span. Research shows clearly that education, exercise, nutritional habits, financial decisions, and social choices early in life have substantial implications for quality of life at advanced ages. Increased longevity demands that we reconsider traditional models of the life course which will necessitate new norms and practices for education, work, and families that span multiple generations. To inspire change on a grand scale, the Center works with more than 150 Stanford faculty, their students and research staffs, as well as leaders from industries that are poised to distribute innovative products and services to the public, thought leaders who help to shape the ideas that influence cultural change, and policymakers who target important challenges and opportunities for long-lived societies. By fostering dialogue and collaborations among typically disconnected worlds, the Center aims to develop workable solutions for urgent issues confronting the world as the population ages. With these collaborations, we aim to redesign how we live our lives so that the great potential of a longer life is fully realized.