all packs, herds, and communities of animals there is some subordination of self-will to secure the realization of the universal will in social existence. And the higher we ascend in the scale of gregariousness the more conspicuous does co-operation become, until among the higher races of civilized man we find that it has in some degree transferred the pressure of the struggle for existence from the individual to the body corporate, and that it tends to do so more and more. Social organization is loose and shadowy when compared with that of living beings, and differentiation of structure and function in it are partial and ill-defined, but still it is readily perceived that its development is regulated by a social process which, although it may seem to emerge from environment and the struggle for life, clearly implies as it goes on not only the harmonious coexistence of different classes differently employed and interested in a larger life than their own, that of the system or nation of which they form, a part, but the subjection of individual self-assertion to social growth, in accordance with some social ideal or, shall we say, design. In the social not less than in the organic process we see pause given to the life struggle and the co-operation of diverse parts to a common end. In highly civilized societies certain classes—propertied and pensioned classes—are practically relieved from the struggle for existence by the operation of moral restraints, and it is the avowed aim of state socialism to make that struggle less and less the concern of the individual and more and more that of the state. In the intercourse between nation and nation traces of co-operation may be recognized.
But it is in sexual relations far more than in the organic or social process that the embryonic forms and cotyledons of the moral sentiments that among mankind, when in full leaf and blossom, mask and overshadow and sometimes choke natural selection may be most clearly recognized. Nutrition is everywhere egotistic, but reproduction is invariably altruistic in its character. In its lowest form, where two exhausted cells flow together, reproduction corresponds with what has been designated protoplasmic hunger; but wherever true sexual union takes place we have activities that are other, regarding and whenever genuine maternity is differentiated we have hints of self-sacrifice. Sexual preferences and the selection of mates have obvious reference to the continuance of the species and the welfare of the offspring and imply co-operation, and the fatality that attends the triumph of motherhood represents the immolation of the individual for the collective advantage. Among the insects we have the pairing of mates preceded by courtship and followed by associated industry, as in the aterechus, where the male and female beetle disinterestedly toil together in rolling up receptacles for their unborn off-