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.

Conflict may be defined as a situation of competition in which the parties are aware of the incompatibility of potential future positions, and in which each party wishes to occupy a position that is incompatible with the wishes of the other.

Almost every organization... exhibits two faces a smiling face which it turns toward its members and a frowning face which it turns to the world outside.

Communication can only take place among equals.

[The historical] development in the international system may almost be defined as the process by which we pass from stable war to stable peace.

Economists are like computers. They need to have facts punched into them.

The economy of the future might be called the "spaceman economy," in which the earth has become a single spaceship, without unlimited reservoirs of anything.