This chapter sets out to explore a theory of sustainable economics, grounded in the functionality and organization of the Earth system. It seeks to find a path to a sustainable future for humanity when viewed through all three lenses of environment, society, and economics. To begin with, the concept of a pluriverse is explained and critiqued. Next, the ecological pluriverse is explored, combining systems theory and thermodynamics. The Earth system consists of many worlds, or biomes, whose characteristics are emergent from the energetic contexts in which each biome finds itself. The biomes also operate their economies in ways that relate to their ecological properties. The totality results in an ecological pluriverse, one world and many worlds, setting the parameters for all life within. Next, the social pluriverse is explored, wherein a sustainable humanity can be seen to exist in resonance with the ecological pluriverse. Finally, the economic pluriverse is addressed, wherein appropriate sustainable economic activity emerges from the social pluriverse and, more fundamentally, the economics of the ecological pluriverse.