Economic progress means the discovery and application of better ways of doing things to satisfy our wants. The piping of water to a household that previously dragged it from a well, the growing of two blades of grass where one grew before, the development of a power loom that enables one man to weave ten times as much as he could before, the use of steam power and electric power instead of horse or human power - all these things clearly represent economic progress.

One of the most important skills of the economist, therefore, is that of simplification of the model. Two important methods of simplification have been developed by economists. One is the method of partial equilibrium analysis (or microeconomics), generally associated with the name of Alfred Marshall and the other is the method of aggregation (or macro-economics), associated with the name of John Maynard Keynes.

The World is a very complex system. It is easy to have too simple a view of it, and it is easy to do harm and to make things worse under the impulse to do good and make things better.

DNA has been aptly described as the first three-dimensional Xerox machine.

Deciding under uncertainty is bad enough, but deciding under an illusion of certainty is catastrophic.

At the opposite pole from the gift is tribute - that is, a grant made out of fear and under threat. A threat is a statement of the form "you do something that I want or I will do something that you do not want.

Don't go to great trouble to optimize something that never should be done at all. Aim to enhance total systems properties, such as creativity, stability, diversity, resilience, and sustainability - whether they are easily measured or not.