Physicists can only talk to other physicists and economists to economists... sociologists often cannot even understand each other.

Where there is hypocrisy, there is hope.

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

Mathematicians themselves set up standards of generality and elegance in their exposition which are a bar to understand.

There are, of course, a number of epistemological questions, some of which lie more in the province of the philosopher than they do the economist or the social scientist. The one with which I am particularly concerned here is that of the role of knowledge in social systems, both as a product of the past and as a determinant of the future.

If the society toward which we are developing is not to be a nightmare of exhaustion, we must use the interlude of the present era to develop a new technology which is based on a circular flow of materials such that the only sources of man's provisions will be his own waste products.

Physicists only talk to physicists, economists to economists-worse still, nuclear physicists only talk to nuclear physicists and econometricians to econometricians. One wonders sometimes if science will not grind to a stop in an assemblage of walled-in hermits, each mumbling to himself words in a private language that only he can understand.