A world of unseen dictatorship is conceivable, still using the forms of democratic government.

As long as man was small in numbers and limited in technology, he could realistically regard the earth as an infinite reservoir, an infinite source of inputs and an infinite cesspool for outputs. Today we can no longer make this assumption. Earth has become a space ship, not only in our imagination but also in the hard realities of the social, biological, and physical system in which man is enmeshed.

What exists, is possible.

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.

[In science any model depends on a pre-chosen taxonomy] a set of classifications into which we divide the enormous complexity of the real world... Land, labor, and capital are extremely heterogeneous aggregates, not much better than earth, air, fire, and water.

The perception of potential threats to survival may be much more important in determining behavior than the perceptions of potential profits, so that profit maximization is not really the driving force. It is fear of loss rather than hope of gain that limits our behavior.

Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist.