The right to have children should be a marketable commodity, bought and traded by individuals but absolutely limited by the state.

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

The proposition that the meek (that is the adaptable and serviceable), inherit the earth is not merely a wishful sentiment of religion, but an iron law of evolution.

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.

The social dynamics of human history, even more than that of biological evolution, illustrate the fundamental principle of ecological evolution - that everything depends on everything else. The nine elements that we have described in societal evolution of the three families of phenotypes - the phyla of things, organizations and people, the genetic bases in knowledge operating through energy and materials to produce phenotypes, and the three bonding relations of threat, integration and exchange - all interact on each other.

All knowledge is gained through an orderly loss of information.

The ability to work with systems of general equilibrium is perhaps one of the most important skills of the economist - a skill which he shares with many other scientists, but in which he has perhaps a certain comparative advantage.