The use of isoquants to describe the production function did not develop to any great extent until the thirties.
Kenneth E. Boulding[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.
Kenneth E. BouldingAre 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?
Kenneth E. BouldingNothing fails like success, because we do not learn anything from it. We only learn from failure, but we do not always learn the right things from failure. If there is a failure of expectations, that is, if the messages that we receive are not the same as those we expected, we can make three possible inferences.
Kenneth E. Boulding