It must be acknowledged that for those who have any care for precision and clearness the study of the feelings and emotions presents great difficulties. Internal observation, always an uncertain guide which leads us but a little way, is here especially questionable. Experiment has given some very useful results, but they are much less important and numerous than in other regions of psychology. Detailed researches and monographs are lacking, so that the subject abounds with questions on which little light has yet been thrown. Finally, the dominant prejudice which assimilates emotional states to intellectual states, considering them as analogous, or even treating the former as dependent oh the latter, can only lead to error. We have, in fact, in every study of the psychology of feeling to choose between two radically distinct positions, and this choice involves a difference in method. Concerning the final and essential nature of states of feeling there are two contrary opinions. According to one, they are secondary and derived, the qualities, modes, or functions of knowledge; they only exist through it; they are “confused intelligence”: that is the _intellectualist_ thesis. According to the other, they are primitive, autonomous, not reducible to intelligence, able to exist outside it and without it; they have a totally different origin: that is the thesis which under its present form may be called _physiological_. These two doctrines exhibit variations which I ignore, as I am not writing their history, but they all come into one or the other of these two great currents. The intellectualist theory, which is of considerable age, has found its most complete expression in Herbart and his school, for whom every state of feeling only exists through the reciprocal relation of representations; every emotion results from the co-existence in the mind of ideas which agree or disagree; it is the immediate consciousness of the momentary elevation or depression of psychic activity, of a free or impeded state of tension. But it does not exist by itself; it resembles musical harmonies and dissonances, which differ from elementary sounds though only existing through them. Suppress every intellectual state, and feeling vanishes; it only possesses a borrowed life, that of a parasite. The influence of Herbart still persists in Germany, and, with some exceptions (Horwicz, Schneider, etc.), complete or mitigated intellectualism predominates.