I am not a professional designer nor a social theorist in a design school. At the same time, my intellectual and professional life has gravitated around design issues, first as a student of chemical engineering (in Cali, Colombia, where I grew up), continuing with my master’s in food science and nutrition planning, and ending with my PhD program in Development Philosophy, Policy, and Planning at Berkeley. Chemical engineering is a design profession, though largely devoted to unsustainable designs; as I finished my engineering degree, I became concerned with issues of food and hunger and, through them, development. As I eventually discovered, development strategies are veritable designs which, more than solving the problems of “underdevelopment,” perpetuate them to infinity. Seventy years after the invention of “underdevelopment,” we are still in the business of “developing” the poorer countries; today under the guise of sustainable development. As a design technology, sustainable development is more intended to sustain development – with its accompanying cadre of well-paid experts, institutions, programs, and strategies – than in genuinely addressing the suffering of so many communities in the Global South. It is, in short, about sustaining the unsustainable.The book builds upon a relatively small but growing subset of critical design studies, whose practitioners emphasize the need to place design always in context, making it socially relevant, ecologically sound, and culturally appropriate. This trend, however, goes beyond reformist approaches. The designers pursuing this novel orientation advocate for a significant overhaul of design approaches and methodologies, away from expert-driven, object-oriented, and market-determined design practices toward collaborative, situated, place-based, and openly transformative approaches. The most farsighted proposals posit a notion of design as a space for contributing to bringing about civilizational transitions, even a “new civilization” (Ezio Manzini) or an age of “Sustainment” (Tony Fry), in contradistinction to the modern civilization, ushered in by The Enlightenment, which is, in actuality, a social order based on a narrow rationality that has systematically produced unsustainable societies. This newer civilizational model or era is described as one in which humans can finally co-exist with the Earth in mutually enhancing manners. In the last instance, what moves these critical designers is a profound caring for the notion that other worlds are, indeed, possible.