In the former instance I experience a feeling of dissatisfaction, the feeling of neglected duty and of remorse; in the latter I have the pleasurable sensation of duty fulfilled. And yet the nature of the object matters little. Only the intensity of the sympathy, together with the individual development of the conscience, determine the intensity of the sense of duty in any given case. An insane person can feel the most vehement sense of duty or remorse without any real object, or as the result of entirely perverted conceptions. As every living creature, particularly if it possesses a separate nervous system, has the instinct of self-preservation, the conscience therefore results directly from the conflict between this instinct and the secondary emotions of altruistic sympathy. These latter are of later origin, and have for the most part been evolved from the attraction between the sexes (sexual love), or from the relationship of parents to the offspring dependent upon them (parental love). The first feelings of duty and of sympathy in the animal kingdom are therefore confined to the family, and adapted to the preservation of the species. They are also exclusive, and may only persist for a short time (as in the case of cats), but frequently they are of lifelong duration. The conjugal fidelity of certain apes and parrots is exemplary. But the necessity of protection against common foes brought about in the case of many animals a ripening of the sense of sympathy, and it became extended to whole groups, so that here and there free communities (swallows, buffaloes, monkeys) have resulted. Finally certain species have developed the senses of sympathy and duty to such an extent that they have led to a complete anarchistic Socialism, as is the case among wasps, bees, and ants. Here the social sense has so far overcome both egotism and altruism limited to a few individuals that it wholly dominates them. The individual devotes his whole energy and labour to the communal existence, and even sacrifices his life for this object. He never, however, sacrifices his life for another single member of the community, unless the latter is of primary importance for the maintenance of the species. One worker-bee does not immolate itself for another, but does so without hesitation for the queen and the hive. It will even empty the whole contents of its stomach into the queen bee’s mouth and starve in order to save her. The altruism of the ants and the bees knows nothing of family affection or sexual love; it is confined absolutely to the hive or nest. Different beehives or ants’ nests are either inimical or indifferent to one another.