Even in Watson’s time, his was not the only type of behaviorism. One of Watson’s most formidable adversaries was McDougall, who agreed with Watson that psychology should be the science of behavior but thought that purposive behavior should be emphasized. Because of its emphasis on goal-directed behavior, McDougall’s position was referred to as hormic psychology. Although McDougall defined psychology as the science of behavior, he did not deny the importance of mental events, and he believed they could be studied through their influence on behavior. In other words, McDougall was a methodological behaviorist. Whereas Watson had concluded that instincts played no role in human behavior, McDougall made instincts the cornerstone of his theory. For McDougall an instinct is an innate disposition that, when active, causes a person to attend to a certain class of events, to feel emotional excitement when perceiving those events, and to act relative to those events in such a way as to satisfy the instinctual need. When the instinctual need is satisfied, the whole chain of events terminates. Thus, for McDougall, instincts and purposive behavior go hand in hand. McDougall believed that the reason humans learn habits is that they satisfy instinctual needs. Also, McDougall believed that instincts seldom, if ever, motivate behavior in isolation. Rather objects, events, and ideas tend to elicit two or more instincts simultaneously, in which case a sentiment is experienced. In the famous debate between Watson and McDougall, McDougall was narrowly declared the winner.