20 THE AMERICAN JOURNAL OF SOCIOLOGY
I cannot tell ; but since I entered that service fourteen years ago, I have been in a multitude of minor ways impressed with two things : first, that in every Scottish community, rural and urban, a hygienic renascence is in progress ; second, that in the many forms it assumes, it has no explicit basis in scientific theory. In attempting, some time ago, to penetrate to the root-idea of the public-health move- ment, I concluded that, rightly or wrongly, we have all taken for granted certain postulates. The hygienic renascence is the objective side of a movement whose ethical basis is the set effort after a richer, cleaner, intenser, life in a highly organized society. The postulates of hygienics whose administrative form con- stitutes the public-health service are such as these : that society or the social group is essentially organic ; that the social organism, being as yet but little integrated, is capable of rapid and easy modification, that is, of variations secured by selection ; that disease is a name for certain maladaptations of the social organism or of its organic units ; that diseases are thus, in greater or lesser degrees, preventable ; that the prevention of disease promotes social evolution ; that, by the organization of representative agencies county councils, town coun- cils, district councils, parish councils, and the like the processes of natural selection may be indefinitely aided by artificial selections ; that thus, by con- tinuous modification of social organism, of its organic units, and of the compound environment of both, it is possible to further the production of better citizens more energetic, more alert, more versatile, more individuated. Provisionally, public health may be defined as the systematic application of scientific ideas to the extirpation of diseases and thereby to the direct or indirect establishment of beneficial variations both in the social organism and in its organic units. In more concrete form, it is an organized effort of the collective social energy to heighten the physiological normal of civilized living.
A science of hygienics might thus be regarded as almost equivalent to the science of eugenics ; character is presupposed in both. The fundamental assump- tion of hygienics is that the human organism is capable of greater things than on the average it has anywhere shown, and that its potentialities can be elicited by the systematic improvement of the environment. From the practical side, hygienics aims at " preparing a place " for the highest average of faculty to develop in.
Take heredity one of Dr. Galton's points. The modern movement for the extirpation of tubercular phthisis began with the definite proof that the disease is due to a bacillus. But the movement did not become world-wide until the belief in the heredity of tuberculosis had been sapped. So long as the tubercular person was weighted by the superstition that tubercular parents must necessarily produce tubercular children, and that the parents of tubercular children must themselves have been tubercular, he had little motive to seek for cure, the fatal- ism being here supported by the alleged inheritance of disease. Now that he knows how to resist the invasion of a germ, he is proceeding in his multitudes to fortify himself. What is true of tuberculosis is true of many other infections. Consequently, every hygienist will agree with Dr. Galton that the dissemination of a true theory of heredity is of the first practical importance. Nor is the evil of a wrom? theory of heredity confined to infectious disease. If the official " nomenclature of diseases " be carefully scrutinized, it will be found that the vast majority of diseases are due either to the attacks of infective or parasitic organisms, or to the functional stress of environment, which for this purpose is better named " nurture." This has recently been borne in upon me by the examina- tion of school children. The conclusion inevitably arising out of the facts is that inherited capacities are in every class of society so masked by the effects of nurture, good or bad, that we have as yet no means of determining, in any individual case, how much is due to inheritance and how much to nurture. There is here an unlimited field for detailed study.
Next, fertility. It is, I suppose, on the whole, true that the less opulent classes are more fertile than the more opulent. But I am not prepared to accept the assumption that the economically " upper classes " coincide with the bio- logically " upper classes." May it not be that the relatively infertile " upper classes " (economical) are only the biological limit of the " lower classes," from
