Are we to regard the world of nature simply as a storehouse to be robbed for the immediate benefit of man? ... Does man have any responsibility for the preservation of a decent balance in nature, for the preservation of rare species, or even for the indefinite continuance of his race?

The use of isoquants to describe the production function did not develop to any great extent until the thirties.

Economic problems have no sharp edges. They shade off imperceptibly into politics, sociology, and ethics. Indeed, it is hardly an exaggeration to say that the ultimate answer to every economic problem lies in some other field.

Even personal tastes are learned, in the matrix of a culture or a subculture in which we grow up, by very much the same kind of process by which we learn our common values. Purely personal tastes, indeed, can only survive in a culture which tolerates them, that is, which has a common value that private tastes of certain kinds should be allowed.

Know this: though love is weak and hate is strong, Yet hate is short, and love is very long.

Equilibrium is a figment of the human imagination.

No science of any kind can be divorced from ethical considerations... Science is a human learning process which arises in certain subcultures in human society and not in others, and a subculture as we seen is a group of people defined by acceptance of certain common values, that is, an ethic which permits extensive communication between them.