_Origin of the Social Feelings—Animal societies—Nutritive societies—The individual and society—Domestic societies—Social instinct has its source neither in sexual nor in maternal love—Gregarious societies—Attraction of like for like—Origin of social tendencies—Accidental and transitory unions, of variable duration, and voluntary—The social tendencies arise from the conditions of existence—Social life does not spring from domestic life—The higher societies among animals: they exclude family relations—Human societies—Two opposite theories of their origin: the family, the horde—Evolution of the family—Evolution of social life—The family and the clan not similar institutions—The moral sense. Two views of its origin: (a) the intellectual, (b) the emotional—They correspond to two stages in its development—Its innateness and its necessity belong to the motor, not the intellectual order—Genesis of the benevolent feeling. Psychological analysis of its generative elements. Facts in support of this—Discoverers in morality—Genesis of the sense of justice—Phases of its development—Conclusion: complexity of the moral sense—Pathology. Elimination of the questions of criminal anthropology. Moral insensibility._ At the moment of beginning the study of the composite emotions which have had the most brilliant career, and played the most important part in human life, it will be well to indicate the course which will be followed, once for all. We cannot, in dealing with the social, moral, religious, æsthetic and intellectual sentiments, discuss the numerous questions which they suggest, and so lose ourselves in endless details. The allotted task of psychology seems to me to be quite clearly defined—viz., to take each feeling _at its origin_ and try to determine its nature and follow its development, in its principal phases, by the help of the documents supplied to us by ethnology, and the history of morals, of religions, and of æsthetic and scientific culture, thus avoiding vagueness and _a priori_ reasoning, without losing our way in an inextricable tangle of facts. In conformity with this plan, we shall begin with the simplest forms of the social instinct in animals, passing from them to man, and thence to the evolution of moral tendencies.