This is now Our doom; which if we can sustain and bear, Our Supream Foe in time may much remit His anger. John Milton, 1667 DEFINITIONS AND IMPLICATIONS What exactly is sustainability? This question is no mere philosophical exercise. Over the last decade, the word 'sustainability' has become a compulsively used word to get at some unspecified but ubiquitous notion of an environmentally ethical and conscious way of life. Businesses, cities, neighbourhoods, buildings, and lifestyles can all be praised as 'sustainable' or criticised as 'unsustainable'. Moreover, there are substantial resources and interests behind the word. Governments, businesses, and civil organisations on all scales are investing heavily in pursuit of 'sustainability,' perhaps because they genuinely believe that this pursuit will improve the quality of life, but quite evidently too because they believe it will give them a competitive advantage vis-a-vis their peers, or perhaps even function as a brand with which they can effectively market their activities. This is not to say that 'sustainability' is not also a principle widely appealed to by both radical environmental and global justice movements. But what makes 'sustainability' interesting and worthy of analysis is precisely its ability to be simultaneously appropriated by corporate and governmental sectors. My home university, for example, recently elected to make 'sustainability' a central feature of its mission, not least because it had received an extraordinarily large grant from a local foundation to do so. At a recent conference funded by this very grant on 'Sustainability and the Humanities', many scholars proposed that our critical ecological insights, goals or visions are in fact better captured by other words, such as restoration, responsibility, or partnership. Yet one cannot but be struck by the fact that neither the local foundation nor the university would have for a single minute considered funding a program on 'Restoration and the Humanities' or 'Responsibility and the Humanities'. What is it about 'sustainability' that enables the word to mobilise wealth and power so effectively? What does it say that this particular word, as opposed to any other, expresses the ecological hopes and fears of so diverse and typically Thinkers ranging from Friedrich Nietzsche to Raymond Williams remind us that the present value of words--their connotative tensions and hidden resonance--emerges in striking ways when we revisit their lexical histories and etymologies. (1) 'Sustainability' is often traced back by its advocates to the 1987 Brundtland Report's definition of 'sustainable development' as 'development that meets the needs of the present without compromising the ability of future generations to meet their own needs'. (2) And indeed, if one understands 'sustainability' to designate the quality of 'forms of human economic activity and culture that do not lead to environmental degradation, especially avoiding the long-term depletion of natural resources', then the Oxford English Dictionary can confirm that this meaning does not date much further back than 1980, or perhaps to the 1970s if we consider certain limited references to 'sustainable growth'. (3) However, the verb 'sustain' upon which the contemporary notion of 'sustainability' depends, reaches all the way back to Old English, where one finds several meanings that remain active and relevant. The most expected of these meanings in the OED is to 'cause to continue in a certain state; to keep or maintain at the proper level or standard', a sense that straightforwardly suggests our ecological appropriation of the word. However, to 'sustain' has at least two other clusters of meanings that bear interestingly on what the word has become in the twenty-first century. Firstly, 'sustain' can mean to 'uphold the validity or rightfulness of; to support as valid, sound, correct, true, or just'. (4) We still use this sense of the word when, for example, in juridical contexts we speak of 'sustaining' an argument. …