"The question is not whether man is free, but whether he can be made free."

"The ideal of a body of knowledge to which all men can contribute and which all men can use has been the great motivating force of science."

"The way to build a car is not to put a man in it and tell him to push."

"The only way to tell whether a given event is reinforcing to a given organism under given conditions is to make a direct test."

"The traditional view of man is an obstacle to a science of behavior."