We might suggest here some of the topics upon which biology has information of value in this bio-social field; many of these we shall discuss later on from our present and special point of view. First of all come the facts regarding the variability and variation of human beings, not alone in physical characteristics, but in respect to psychic traits as well. Here as in all organisms we must distinguish between true variations and bodily modifications; that is, we must be careful to make, as far as possible, the biological distinction between innate and acquired traits, particularly in considering mental characteristics. Next must come consideration of the facts of heredity. This is undoubtedly the field of greatest importance to the Eugenist; facts of no other kind are of equal significance in determining the course of eugenic practice. We now have a fairly extensive working basis here from which to discuss heredity in man. The various phases of human selection should be noticed, in particular that known as selective fertility or differential fertility in different social groups or classes. Another evolutionary factor of importance here is that of "isolation" in the many and varied forms which it assumes in human society, especially those which result from assortative and preferential mating, and from the operation of social convention, restrictions in marriage, and the like.
Before discussing any of these subjects let us offer here just a word of caution to the enthusiast. The results gained in one field of science cannot be transferred in toto to another field and there be found to fit. Biology has learned much from Physics and Chemistry, but the biological applications of the laws of these sciences must be carried out with the greatest care. Such transference has often been premature and attended by results retardative to progress in the field of Biology. Any formula borrowed from one science and applied in another must be rigorously tested under the new conditions. The indiscriminating application of biological laws in the field of sociology may result in confusion and retardation in the progress of both sciences, or at any rate in their practical applications. As Thomson points out in writing on this topic, human society is not only a complex of individual activities of a strictly biological character, but also and further it involves an integration and regulation of those activities which are not yet, at least, susceptible of concrete biological analysis. Thomson says: "The biological ideal of a healthful, self-sustaining, evolving human breed is as fundamental as the social ideal of a harmoniously integrated society is supreme." The great danger here lies in forgetting the fundamental and general character of the biological principles. The ideals of biology and sociology need not coincide, often they do not, but they must not conflict. In practice Eugenics must be largely a social matter; but in its theory, its fundamentals, it must be largely biological.
The coming together of biology and sociology, and their common search for guiding principles in their common endeavor is likely to have results of several kinds. It is likely to bring out more clearly than has yet been done the distinction, in human life and society, between that which is fundamentally biological or animal, and that which is distinctly social. Such information will prove of especial value later when the time comes for the suggestion and carrying out of a definite eugenic program, when the time comes for the real eugenic organization of society. And further the close rapprochement of the two subjects will doubtless result in mutual aid and suggestion in the development of each subject in its own stricter field, outside the limits of their common meeting ground.
Before bringing this introductory chapter to a conclusion we should suggest one further caution which must be borne in mind. There may at times seem to be suggestions of antagonism between the biological and the social conceptions of what is eugenic and what is not. Much of this apparent discord will disappear if we recognize that after all the overlapping areas of the two subjects which have fused into the subject of Eugenics are relatively small portions of either whole subject. Sociology has for one of its aims, perhaps its chief aim, the improvement of the present condition of society. The sociologist is interested in the improvement of social conditions to-day and to-morrow. He wants to improve housing conditions, food and milk supplies, to reduce the curses of alcoholism, poverty, and crime, to take the children out of the factory and their mothers out of the sweatshop and put them into schools or under humane conditions of labor. And so on through a long list. The biologist or Eugenist is of course heartily with the sociologist in these endeavors, but as a human being, not as a biologist or Eugenist. For the Eugenist is, as such, by deliberate assumption and definition, directly interested in only such conditions as affect the innate characteristics of the race, conditions which may not have direct reference to the present generation at all, but to the next and to future generations. As a Eugenist he is not concerned with factory legislation, alcoholism, or play grounds, unless it can be shown that there is a relation between these things and the innate mental and physical properties of the race. If there is such a relation, of improvement or impairment, these are eugenic topics; if there is no such relation they are purely social topics, and the Eugenist does not deal with them, not because they are not worth dealing with, but because they are then by definition outside his field. In the end the Eugenist hopes, with the Sociologist, to accomplish these social betterments, but he believes that these will come as by-products in the process of innate racial improvement—improvement in the inherent, physical, mental, and moral qualities of the human kind, and that accomplished in this way the results will be more stable and permanent than any accomplished by attacking the problems as such and separately, largely leaving out of account the real and fundamental cause—bad human protoplasm.
Eugenics is not offered as a universal cure for social ills: no single cure exists. But the Eugenist believes that no other single factor in determining social conditions and practices approaches in importance that of racial structural integrity and sanity. The Eugenist would oppose only those social activities, if such there be, that conflict with his ideal of genuine, progressive, human evolution. The main question which the Eugenist would raise here is largely that of the economy of effort—whether it were not better by concentrating upon a few activities, known to give permanent results, once for all to end an intolerable social condition, rather than to attempt the Sisyphean task.
In conclusion let us quote a few sentences from Francis Galton. "Charity refers to the individual; Statesmanship to the nation; Eugenics cares for both.... I take Eugenics very seriously, feeling that its principles ought to become one of the dominant motives in a civilized nation, much as if they were one of its religious tenets.... Man is gifted with pity and other kindly feelings; he has also the power of preventing many kinds of suffering. I conceive it to fall well within his province to replace Natural Selection by other processes that are more merciful and not less effective. This is precisely the aim of Eugenics. Its first object is to check the birth rate of the Unfit instead of allowing them to come into being, though doomed in large numbers to perish prematurely. The second object is the improvement of the race by furthering the productivity of the Fit, by early marriages and the healthful rearing of their children. Natural Selection rests upon excessive production and wholesale destruction; Eugenics on bringing no more individuals into the world than can be properly cared for, and those only of the best stock."