The political economies of the contemporary world - most especially the advanced capitalist nation states - are on a collision course with natural limits, biodiversity conservation, and ecosystem health. If they undermine their own natural and biological foundations, they will erode their institutional and normative foundations as well. This paper discusses an agenda of critical theoretical and conceptual inquiry designed to address this conundrum that looms over our current modes of economic thinking. It considers two options: a discourse of economic adjustment to natural limits and a discourse of ecological accommodation. Behind the discourse of adjustment stands a narrative of human science and technology as a continuous process of adapting nature to human action rather than accommodating human action within the context of nature. Behind the discourse of accommodation stands a narrative of transition and discontinuity, which maintains that the technological and economic future will be different from the past, not simply in degree, but in kind. The paper discusses aspects of economics and democratic governance that require reconceptualization in the light of ecological limits, including the notions of fungibility of system functions, discounting, intergenerational equity, and external costs. It also discusses the question of the continuing viability of democratic governance systems to meet the requirements of ecological accommodation. Overall, the paper defends the thesis that by continuing to ignore fundamental aspects of the natural world upon which human economic activity draws, the management and governance of contemporary political economies will gradually erode the capacities to perform these functions and to fulfill these goals, and they will lose their social and ethical legitimacy