One of the main features of the contemporary environmental crisis is that no one has a clear pictue of what is taking place. Environmental problems are real enough but they bring home the inadequacy of our knowledge. How does the natural world realate to the social world? Why do we continue to have such a poor understanding? How can ecological knowledge be made to relate to our understanding of human society? The book argues that the division of labour is a key but neglected factor underlying people's inability to adequately understand and relate to the natural world. The argument extends Marx's theory of alienation to account for inadequate knowledge and therefore inadequate concern for nature. Using recent developments in 'critical realist' philosophy, the book aims to find ways of reorganizing knowledge in the light of ecological consciousness. It also corrects the emphasis of much environmental literature by focussing on production rather than consumption.