Twenty-five hundred years ago it might have been said that man understood himself as well as any other part of the world. Today he is the thing he understands least.
B. F. SkinnerThe human species took a crucial step forward when its vocal musculature came under operant control in the production of speech sounds. Indeed, it is possible that all the distinctive achievements of the species can be traced to that one genetic change.
B. F. Skinner