p.1 While most people support sustainable development, many believe that its benefits must be weighed against other objectives such as economic growth and consumer desires for recreation, comfort and status. However, sustainability is not an option but a requirement. Any economy that is not sustainable will go bankrupt: any biological system that is not sustainable will die.

p.7 So please do not take the theories advanced here to be the final word on anything. To the extent that they add to our understandings of how societies function and change, they are useful tools for analysing real problems and developing practical solutions. But in the end they are only ways of viewing and interpreting reality. Other perspectives can also be valid. Moreover, no theory is the ultimate theory. Like the process of evolution, each stage builds on the last, and each becomes in turn a stepping stone for further developments.