The distribution of the human race over the face of the earth has thus been governed by a different law from that which has governed the distribution of plants and animals. In the latter case, the degree of perfection of the types is exactly proportional to the intensity of heat and other material conditions favorable to the development of physical life. _This is the law of a physical order._ In the former case, in man, the degree of perfection of the types is in proportion to the degree of intellectual and moral improvement, and to the physical conditions favorable to intellectual and moral development. _This is the law of a moral order._ This difference between the two laws has its ground and reason in the essential difference between the nature and destination of these different orders of being. The plant and the animal are not destined to become a different thing from what they already are. The end of their existence is already attained. The development of each individual is bound to an immutable necessity of nature. Therefore vegetable life and organization are ceaselessly uniform; there are always the same cellular structures and the same morphological forms. Unreasoning and instinctive life never leaves its sphere. The beaver builds its dam, lives, and dies, just as it did six thousand years ago. The bee builds the same hexagonal cell she built before the flood. There is an all-pervading order in the physical world, But with man it is quite otherwise. Man, created in the image of God, is a free moral being. He is not solely under the dominion of mere nature-conditions, and he is therefore a progressive being. The physical man is not the true man; the body is not an end, but a means. There is another man--the intellectual, the moral, the spiritual man--which grows up with the body, and to which the physical man is a servant and minister. The unfolding, the development, the perfection of this spiritual nature is the grand end of man. This development can only take place under freedom; this nature be unfolded only by education; the maturity and the perfection of man secured only by the exercise and discipline of his spiritual powers.[392]