The psychology of states of feelings, it is generally recognised, is still in a confused and backward condition. Although it has benefited in some measure by the contemporary allurement of psychological research, it must be acknowledged that it has only exerted a moderate seduction upon workers; the preference has been given to other studies, such as those of perception, of memory, of images, of movement, of attention. If any proof is necessary we may find it in the bibliographies, now published in Germany, America, and France, which give the psychological inventory of each year; of the whole number of books, memoirs, and articles which appear, less than the twentieth part, on an average, relates to the feelings and emotions. It is a very small part compared to the part played by the emotions and passions in human life, and this region of psychology is not deserving of such neglect. It is true that in recent years W. James and Lange seem to have brought this state of stagnation to an end. Their thesis, paradoxical in appearance, has aroused, especially in America, many discussions, criticisms, defences, and, what is of more value, observations and researches.