ABSTRACT
William James-the author of one of the first physiological theories of emotions more than a century ago-published a paper with a most remarkable title: “What is emotion?” (James, 1884). Nevertheless, one hundred years after this question was formulated, we find in the textbook “Human Physiology” the following revelation: “Despite the fact that each of us knows what emotions are, it is impossible to give the emotional state a precise scientific definition…. At the present time there is no generally
accepted scientific theory of emotions, nor any precise data concerning which centers emotions arise in, how they arise, or what their nervous substrate is” (Schmidt and Thews, 1983).
