On January 20, 1949 US President Harry S. Truman officially opened the era of development. On that day, over one half of the people of the world were defined as "underdeveloped" and they have stayed that way ever since. This book explains the origins of development and underdevelopment and shows how poorly we understand these two terms. It offers a new vision for development, demystifying the statistics that international organizations use to measure development and introducing the alternative concept of buen vivir: the state of living well. The authors argue that it is possible for everyone on the planet to live well, but only if we learn to live as communities rather than as individuals and to nurture our respective commons. Scholars and students of global development studies are well-aware that development is a difficult concept. This thought-provoking book offers them advice for the future of development studies and hope for the future of humankind.