The subject of social movements has long been a major sociological specialism. New movements constantly arise in response to new situations, environmental, social and political; old movements may fade away or revitalize themselves. Movements can be thought of as praxis–the unity of theory and practice, oriented towards the future, and as both experiments in actually creating social change, and as sources of inspiration and aspiration to plant and concretize the idea of the possibility of change in the minds of people. Movements are by their very nature future oriented, and have often been more than allies in the pursuit of positive social change, but actually the cutting edge of such change–cultural, social or political. The dissident imagination as an anticipatory tool can destabilize assumptions and set new socio-cultural horizons that have the power to mobilize powerful movements of dissent and renewal. The chapter also presents an overview of the key concepts discussed in this book.