For our purposes sustainability is defined as the persistence over an apparently indefinite future of certain necessary and desired characteristics of the socio-political system and its natural environment.
(Robinson et al. 1990, p 39)

Sustainability is defined throughout this paper as: non-declining utility of a representative member of society for millennia into the future.
(Pezzey 1992, p323)

Sustainability is a relationship between dynamic human economic systems and larger dynamic, but normally slower-changing, ecological systems in which: (1) human life can continue indefinitely; (2) human individuals can flourish; (3) human cultures can develop; but in which (4) the effects of human activities remain within bounds, so as not to destroy the diversity, complexity, and function of the ecological life-support system. (Costanza 1992, p 111 and Norton 1992)

Sustainable development is itself something of a paradox. The phrase implies that something must change but that something must also remain constant. (Holling 1995, p 25)

Wrapped within the intellectual cocoon of environmental studies it is too easy to believe that the rest of the world carries the same basic values and perspective as I and fellow scholars. The following quotes are included primarily to dispel this belief, warning of the dangers of such an assumption.

"We now have in our hands - in our libraries, really - the technology to feed, clothe and supply energy to an ever-growing population for the next 7 billion years. Most amazing is that most of this specific body of knowledge developed within the past hundred years or so, though it rests on knowledge that had accumulated for millennia, of course. Indeed, the last necessary additions to this body of knowledge - nuclear fission and space travel - occurred decades ago. Even if no new knowledge were ever invented after those advances, we should be able to go on increasing forever, improving our standard of living and our control over our environment. The discovery of genetic manipulation certainly enhances our power greatly, but even without it we could have continued our progress forever." (Simon in Costanza 1995, p 89)

"Maddox also endorses Beckerman's "conclusion that there must be 'major flaws' in the argument that the Earth's resources are finite." (Common 1995, p 101)

"Solow [urges thinking about] "sustainability as a matter of distributional equity between the present and the future." ...
By this definition, sustainability had never been much of a problem in the modern era and would not be unless future developments cause a drastic reversal of the economic trends of the nineteenth and twentieth centuries. As Solow observed, "you could make a good case that our ancestors, who were considerably poorer than we are, ... were probably excessively generous in providing for us." ... Based on this past precedent, and given the general value presumption in favor of a more equal distribution of income, the current generation perhaps should be looking to increase its consumption, to redistribute income from the richer people expected in the future to those of us who are less well off today.
This economic way of thinking about sustainability obviously is not what many people who now express concern about the issue have in mind." (Nelson 1995, p 142)