We have seen that in certain respects operant reinforcement resembles the natural selection of evolutionary theory. Just as genetic characteristics which arise as mutations are selected or discarded by their consequences, so novel forms of behavior are selected or discarded through reinforcement.

At this very moment enormous numbers of intelligent men and women of goodwill are trying to build a better world. But problems are born faster than they can be solved.

I may say that the only differences I expect to see revealed between the behavior of the rat and man (aside from enormous differences of complexity) lie in the field of verbal behavior.

It is a surprising fact that those who object most violently to the manipulation of behaviour nevertheless make the most vigorous effort to manipulate minds.

We have not yet seen what man can make of man.

A person's genetic endowment, a product of the evolution of the species, is said to explain part of the workings of his mind and his personal history the rest.

The simplest and most satisfactory view is that thought is simply behavior - verbal or nonverbal, covert or overt. It is not some mysterious process responsible for behavior but the very behavior itself in all the complexity of its controlling relations.