The discussion of sustainability in environmental economics continues to be plagued by considerable disagreement and obscurity as to both the conceptual and the operational content of the term. These disagreements arise due to different disciplinary perspectives, the axiomatic foundations of the models that are used to explore the concept, and interpretations of sustainability at the policy level. The discussion is further plagued by ill-defined philosophical and ethical differences over issues of both intra- and inter-generational equity. This paper seeks to clarify matters through the development of a mathematical model of resource allocation that embraces both economic and ecological concepts of sustainability, drawing on models and insights from ecology to produce a sustainable and stable system.