"We are all controlled by the world in which we live, and we are all engaged in controlling the world in which we live."

"The self is a repertoire of behavior appropriate to a given set of contingencies."

"I am sometimes asked, 'Do you think of yourself as you think of the organisms you study?' The answer is yes."

"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."

"We can't have a science of behavior if we insist that behavior is not determined."