a. The idea which still bulks most largely in the popular mind, as contributed by biology to social theory, is unquestionably that of the struggle for life or the survival of the fittest. It should be noticed that the social application of this analogy rests entirely on the comparison of a human society, not to the individual animal organism, and still less to the individual mind; but to a whole animal species or even to the aggregate of all animal species, so far as they or their members are in competition with one another. One whole side of the sociological {24} doctrine, which Mr. Spencer has advocated with unwearied persistence, is founded upon this application of the biological analogy, and the paradox which he has made his principle professes to be borrowed directly from the dealings of nature with the individuals of the animal species. This paradox, that benefits should be assigned inversely as services in infancy but directly as services among adults, is his ultimate sociological basis; the modification of which, to suit human society, by the introduction of benevolence or altruism, so to speak, on the top of it, only serves to display its inadequacy. But we may take it that the analogy of the struggle for life has made it clear that, in any given position, life can be maintained only in virtue of definite qualities adapted to that position. And formal as this principle is when taken by itself, its application in human society can never be unnecessary. b. A more recent school has insisted on the complementary analogy, which might be taken as resting upon the comparison of a society with an individual organism. Here, it must be remembered, lay the resemblance which, in this region of ideas, first caught the eye of social philosophers in antiquity. But it is alleged that the aspect of co-operation can be traced as between individual members of the animal world no less than between the parts of a single organism, and it is affirmed that the view which sees nothing but internecine competition in the animal kingdom has been too rough and too superficial in its reading of the facts. And therefore it is suggested that the phenomena of social fellowship, no less than those of individual competition, have their source {25} and root in the world of lower nature; and perhaps sociology is now not far from the recognition that competition and co-operation are simply the negative and positive aspect of the same general fact--the fact of the division of labour, of essentiality of function, and of uniqueness of true individual service. If it is suggested by the one organic analogy that life depends upon qualities adequate to the position which is to be filled, it is made obvious by the other that the qualities which satisfy the claims of a certain position are those, in general and in principle, by which a function is discharged in the service of the whole.