Sure, if you stretch the meaning of "behavior" far enough, that quote is true because it becomes a tautology. However, Skinner had some pretty specific ideas a

Sure, if you stretch the meaning of "behavior" far enough, that quote is true because it becomes a tautology. However, Skinner had some pretty specific ideas about what "behavior" meant and probably wouldn't have included stuff like playing a chess game against oneself in one's head.