This text examines the challenges of ecological thought for the assumptions within the traditions of social and political theory. Ecological concerns are often grafted onto existing approaches, but this book examines how the fundamental questions raised by a green perspective transform the terms of reference of modern thinking. Mark J. Smith outlines the distinctive features of ecological thought and examines two contentious areas of environmental ethics: the obligations for present generations to future generations and the relationship of human to non-human animals. Through these case studies, the highlights some of the difficulties and contradictions of applying conventional ideas of rights and justice to environmental issues, pointing the way to a new politics of obligation grounded upon ecological citizenship. Designed as a student text in environmental studies, politics and sociology, this book is essential reading for those with a wider interest in ecology and the environment.