Abstract
The idea of sustainability is an odd composite of imagination and accounting. Environmental history is a permissive historical subdiscipline, and this essay is about the environmental???economic???intellectual history of an environmental idea, sustainability, which is historical in the sense that it is very old, and historical, too, in the sense that it is an idea about history, or about imagining the future in relation to the past. One of the oddities of the last several decades is that these old ideas have been transformed into the most celebrated of all the dicta of environmental policy, or an aspiration of UN commissions, ???strategy consultancies???, and very large government agencies