Kent A. Peacock

The idea of sustainability is simple: an arrangement is sustainable if it can go on indefinitely; it is unsustainable if it cannot. Living on the interest from an inheritance is sustainable; drawing down the principal is not. An unsustainable ecology is one that, for mathematical or biophysical reasons, undermines the conditions necessary for its own continuance, while a sustainable ecology is one that is self-supporting. Thus sustainability is not a moral evaluation (although it has large moral implications); it has to do with whether or not a certain thing can work in a certain way. ...