It is hard to separate the causation of disease in man from the influence which organized society exercises on him. The relations are many and complex, acting in divers ways, and not always with visible directness. For one thing, if you think of it, the important factor of heredity in the causation of disease is, truly and broadly considered, a social factor. And when we mention environment, the other half of the entire etiologic circle, it is readily seen that that in particular depends on the social aggregate and its intelligence and activities in behalf of the preservation of health for its composition and complexion, for the power of doing good or evil, for its influence on health and disease.
Man probably suffered from certain diseases and accidents in his pre-social days, but that the greatest percentage of man's present ills is socially caused, directly or remotely, is a certainty.