This is a textbook intended for students who have had an introductory course in psychology. It is based on the literature of academic psychology and also on related physiological research, such as that of Cannon and Bard. It digests this very extensive literature and reviews simply and clearly many of the theories of emotion. The author proceeds upon the definition of emotion as a disruption or disorganization of the individual. In other words, when he speaks of emotion he has in mind acute emotional states of sufficient intensity to interfere with normal integrated functioning. The obvious difficulties in this view are resolved to some extent, but not fully, by the concepts of attitude and motivation