In this new view of the human body, science not only exhibits the growth and perfection of man as the goal toward which God has been moving from the first, but also throws light upon the sinfulness of man and the conflicts that rage within the soul. Man is seen to be a double creature. The spirit man rides a man of flesh and is often thrown thereby and trampled under foot. There is a lower animal nature having all the appetites and passions that sustain the physical organization; but super-imposed thereon, is a spiritual man, with reason and moral sentiment, with affection and faith. The union of the two means strife and conflict; the doing what one would not do and the leaving undone what one would do. The poet describes the condition by saying: "The devil squatted early on human territory, and God sent an angel to dispossess him." The animal nature foams out all manner of passions and lusts. From thence issue also lurid lights and murky streams. But the under man is not the true man. The soldier rides the horse, but is himself other than his beast. Man uses an animal at the bottom, but man is what he is at the top. Sin is the struggle for supremacy between the animal forces and the higher spiritual powers. The passions downstairs must be subordinated to the people upstairs. In some men the animal impulses predominate with terrible force, and their control is not easy. It is as if a child should try to drive a chariot drawn by forty steeds of the sun. When a man finds that he can not dam back the mountain stream, nor stop up its springs, he learns to use the stream by building a mill, and controlling the pressure of the flood for grinding his corn. Similarly, the problem of life is for the upper man to educate, control, and transmute the lower forces into sympathy and service. The combative powers once turned against his fellows must be turned against nature and used for hewing down the forests, bridging rivers, piercing mountains. Thus every animal force and passion becomes sacred through consecration to mental and spiritual ends and aims.