But in fact morals is the most humane of all subjects. It is that which is closest to human nature; it is ineradicably empirical, not theological nor metaphysical nor mathematical. Since it directly concerns human nature, everything that can be known of the human mind and body in physiology, medicine, anthropology, and psychology is pertinent to moral inquiry. Human nature exists and operates in an environment. And it is not "in" that environment as coins are in a box, but as a plant is in the sunlight and soil. It is of them, continuous with their energies, dependent upon their support, capable of increase only as it utilizes them, and as it gradually rebuilds from their crude indifference an environment genially civilized. Hence physics, chemistry, history, statistics, engineering science, are a part of disciplined moral knowledge so far as they enable us to understand the conditions and agencies through which man lives, and on account of which he forms and executes his plans. Moral science is not something with a separate province. It is physical, biological and historic knowledge placed in a human context where it will illuminate and guide the activities of men. The path of truth is narrow and straitened. It is only too easy to wander beyond the course from this side to that. In a reaction from that error which has made morals fanatic or fantastic, sentimental or authoritative by severing them from actual facts and forces, theorists have gone to the other extreme. They have insisted that natural laws are themselves moral laws, so that it remains, after noting them, only to conform to them. This doctrine of accord with nature has usually marked a transition period. When mythology is dying in its open forms, and when social life is so disturbed that custom and tradition fail to supply their wonted control, men resort to Nature as a norm. They apply to Nature all the eulogistic predicates previously associated with divine law; or natural law is conceived of as the only true divine law. This happened in one form in Stoicism. It happened in another form in the deism of the eighteenth century with its notion of a benevolent, harmonious, wholly rational order of Nature.