I have been gradually coming under the conviction, disturbing for a professional theorist, that there is no such thing as economics - there is only social science applied to economic problems.

Mathematics brought rigor to Economics. Unfortunately, it also brought mortis.

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.

Reality, in its quantitative aspect, must be considered as a system of populations... The general study of the equilibria and dynamics of populations seems to have no name; but as it has probably reached its highest development in the biological study known as 'ecology,' this name may well be given to it.

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 Jacob Viner, "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.

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.

[on the theory of the firm] It is exactly analogous to the analysis of the reactions of a consumer by means of indifferent curves. Indeed, a consumer is merely a 'firm' whose product is 'utility.'