That human nature admits of sympathetic instincts, or, according to the name given them by Comte, _altruistic_ instincts, is not a postulate but a fact. Positive psychology proves it. It is one of the solid portions of Gall’s doctrine. To be convinced of this it is enough to observe men, children, and even animals. Without these instincts, moreover, society would not subsist. Metaphysicians who considered man as a being acting chiefly through reasoning, may have imagined a society founded upon the expressed or tacit consent of the contracting parties. In reality, before all things men obey their inclinations. If they live in society, it is assuredly because their affective faculties lead them to it. Without inborn altruistic tendencies there can be no society and no morality. But biology has proved that, since organic life preponderates over animal life, the selfish instincts are naturally stronger than the sympathetic ones. How could the latter succeed first in counter-balancing and then in dominating the former? This problem would have no solution if the progressive ascendency of the altruistic instincts, very weak originally, were not favoured by two orders of conditions, the one subjective, the other objective, whose action is unceasingly felt. The following development of domestic and social affection is, in the first place, the result of the fact that man lives in society, and, consequently, in continual relation with his neighbours and his fellows. For, as we know, habitual exercise favours the development of organs and of functions. Further, the natural inferiority of the altruistic inclinations is compensated for by their aptitude for “indefinite extension.” They can grow in all the members of a group at the same time. Far from their being obstacles in each other’s way, the stronger altruism in one awakens and encourages nascent altruism in others. On the contrary, forms of selfishness tend to exclude each other. Save in the case of a more or less durable coalition, their rival claims clash with each other, to the peril of social peace. They are bound to make mutual concessions. They are never altogether repressed; however, social life obliges them to dissimulate and to restrain their most violent outbursts.