"It is almost as hard to define mathematics as it is to define economics, and one is tempted to fall back on the famous old definition attributed to, “Economics is what economists do,” and say that mathematics is what mathematicians do. A large part of mathematics deals with the formal relations of quantities or numbers."

“It is much more accurate to identify the factors of production as know-how , energy, and materials, for, as we have seen, all processes of production involve the direction of energy by some know-how structure toward the selection, transportation, and transformation of materials into the product”

“Equilibrium is a figment of the human imagination.”

“One advantage of exhibiting a hierarchy of systems in this way is that it gives us some idea of the present gaps in both theoretical and empirical knowledge. Adequate theoretical models extend up to about the fourth level, and not much beyond. Empirical knowledge is deficient at practically all levels.”

“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.”

“The very act of thinking about power in our lives and experiences creates a process of revelation and self-analysis that may even make us look at ourselves in a new light... thinking about power and its complex manifestations may not simply lead to a better understanding of the abstract complexities of society, but may have an effect on one‟s own image and identity. Perhaps a warning label should be placed on the cover...”

“Without the heroic, man has no meaning; without the economic, he has no sense. Economic man is most likely to be economic woman — a good wife, pulling the coat tails of her heroic husband, checking his extravagances of speech and action with words of caution and good sense. But without the heroic coat tails to pull, life for both of them would be dull and savorless indeed.”