The authors outline a strategy for dealing with the new challenges of sustaining natural resources and human institutions. Without compromising their scientfic objectivity, they argue that sustainability is a matter of human values. Since it affects many people, discussions of sustainability inevitably enter the political arena. The authors maintain that big (and increasingly complex) government may reduce sustainability and they see commerce as a having a central and potentially very positive role in sustainaiblity. On the other hand, they do show explicit concern for the factors that many economists dismiss as "externalities". The authors use the concepts of scale, hierarchy and the criteria of organism, landscape, population and community to address the central issues of ecological sustainability with concrete implications for ecology and management.