In calling society an ecological system we are not merely using an analogy; society is an example of the general concept of an "ecosystem" that is, an ecological system of which biological systems - forests, fields, swamps - are other examples.

Communication can only take place among equals.

[The notion of equilibrium] is a notion which can be employed usefully in varying degrees of looseness. It is an absolutely indispensable part of the toolbag of the economist and one which he can often contribute usefully to other sciences which are occasionally apt to get lost in the trackless exfoliations of purely dynamic systems.

Accounting for the most part, remains a legalistic and traditional practice, almost immune to self-criticism by scientific methods.

[There will be movement toward] behavioral economics... [which] involves study of those aspects of men's images, or cognitive and affective structures that are more relevant to economic decisions.

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.

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.