At every turn the variations in individual perspectives on human rights and potentials, contrasting philosophies on social justice and political structure, and even debates over the best solutions to pressing social problems reflect the vital tension between the one and the many. Are humans, as a species, motivated more by selfish desires or by a commitment to helping others? Can society require that individuals contribute to a common good, even when they will not personally benefit from it? Is a commitment to a common good that will benefit generations to come more morally laudable than working diligently to achieve personal gain? Does capacity for self-sacrifice transform the effective leader into a benevolent one? The chapters in this book draw on psychology, anthropology, history, philosophy, political science, and biology to answer these questions about the inherent tension between the individual and the collective, yielding insights into the nature of philanthropy, the history of individualism in America, brain mechanisms that sustain cooperation, altruism, volunteerism, international aid, and the evolutionary roots of social compassion.