Sustainability implies that the system in question supports the continuance of the practice, the institution, or the phenomenon in a roughly stable state, although it is possible to conceptualize systems that are in constant yet orderly states of change. The important empirical question for sustainability is whether the practice or phenomenon is compatible with continuous (or cyclical) reinforcement or reproduction of the underlying system. There is a nonzero probability that the earth will be hit by a comet and fracture into pieces sometime in the next 100 years, but it would be silly to...

Sustainability implies that the system in question supports the continuance of the practice, the institution, or the phenomenon in a roughly stable state, although it is possible to conceptualize systems that are in constant yet orderly states of change. The important empirical question for sustainability is whether the practice or phenomenon is compatible with continuous (or cyclical) reinforcement or reproduction of the underlying system. There is a nonzero probability that the earth will be hit by a comet and fracture into pieces sometime in the next 100 years, but it would be silly to argue that our current systems of agriculture are unsustainable because they would not survive such an impact.