March 11, 2019 / Last updated : March 5, 2019 B. F. Skinner Foundation Skinner's Quote of the Day Recent Issues. Chapter 10: Laurence Smith’s Behaviorism and Logical Positivism. Quote 2 “I preferred radical behaviorism, which accepted the existence of private states, but as states of the body, the study of which should be left to physiology.” (p. 110)