Indigenous or local knowledge and modern, scientific knowledge have become increasingly separated in the process of modernization, and have often been assumed to be fundamentally different. In a world with unprecedented human impact on the environment, characterized by biophysical and sociocultural globalization, both the necessity of this separation and the assumption of fundamental differences need to be problematized. The question of how similar or different scientific knowledge and indigenous knowledge are, and how they might work together to help solve the problems of ‘development’, has immense practical and ethical implications. It also has immense theoretical importance – for better understanding the relationship between knowledge, action and environment (the world of things and actions outside of the mind) has the potential for improving the efficiency of consciously directed (teleological) human adaptation, for example for ‘sustainable’ interventions. It can help us to discriminate the general from the particular, an essential prerequisite for policy at all levels.At the same time, an important test of theory is its practical efficacy – the results of its application to understanding and solving human-environmental problems.