The development of the Third World countries and the global state of the environment present humanity with two of the most urgent and intractable problems of the late twentieth century. Only in the last decade or so have attempts been made to relate theoretically these two sets of problems. The debate is still unsystematic and confusing and the different positions adopted are often in conflict with one another. A contributor to the discussion states frankly in a recent book: ‘Despite the continuing efforts of international organizations to promote environmental issues, no generally recognized model of the relationships between environment and development is available.’1 However, this commentator, like others in the new ‘ecodevelopment school’, regards the question as a technical one which can be resolved in a theoretical vacuum. What is needed, and what I try to achieve here in a preliminary way, is a survey and conceptual clarification of the whole theoretical field. I take this to be an exercise in the philosophy of political economy.