For palaeontology, zooelogy, history, social and political science, and philosophy are really only parts of one great science, of biology in the widest sense, in distinction from the narrower sense in which it is now used to include zooelogy and botany.  They form an organic unity in which no one part can be adequately understood without reference to the others.  You know nothing of even a constellation, if you have studied only one of its stars.  Much less can the study of a single organ or function give an adequate idea of the human body.

Only when we have attained a biological history can we have any satisfactory conception of environment.  As we look about us in the world, environment often seems to us to be a chaos of forces aiding or destroying good and bad, fit and unfit, alike.

But our history of animal and human progress shows us successive stages, each a little higher than the preceding, and surviving, for a time at least, because more completely conformed to environment.  If this be true, and it must be true unless our theory of evolution be false, higher forms are more completely conformed to their environment than lower; and man has attained the most complete conformity of all.  Our biological history is therefore a record of the results of successive efforts, each attaining a little more complete conformity than the preceding.  From such a history we ought to be able to draw certain valid deductions concerning the general character and laws of our environment, to discover the direction in which its forces are urging us, and how man can more completely conform to it.

If man is a product of evolution, his mental and moral, just as really as his physical, development must be the result of such a conformity.  The study of environment from this standpoint should throw some light on the validity of our moral and religious creeds and theories.  It would seem, therefore, not only justifiable, but imperative to attempt such a study.

Our argument is not directly concerned with modern theories of heredity, or variation, or with the “omnipotence” or secondary importance of natural selection.  And yet Naegeli, and especially Weismann, have had so marked an influence on modern thought that we cannot afford to neglect their theories.  We will briefly notice these in the closing chapter.

CHAPTER I

THE PROBLEM:  THE MODE OF ITS SOLUTION

The story of a human life can be told in very few words.  A youth of golden dreams and visions; a few years of struggle or of neglected opportunities; then retrospect and the end.

        “We come like water, and like wind we go.”