Page:Popular Science Monthly Volume 33.djvu/171

 by the conclusions we draw on this point, is obvious. If a nation is modified en masse by transmission of the effects produced on the natures of its members by those modes of daily activity which its institutions and circumstances involve; then we must infer that such institutions and circumstances mould its members far more rapidly and comprehensively than they can do if the sole cause of adaptation to them is the more frequent survival of individuals who happen to have varied in favorable ways.

"I will add only that, considering the width and depth of the effects which acceptance of one or other of these hypotheses must have on our views of Life, Mind, Morals, and Politics, the question—Which of them is true? demands, beyond all other questions whatever, the attention of scientific men."—Nineteenth Century.



N seeking the explanation of highly complex phenomena, many simple and entirely inadequate causes are apt to be assigned by men who have become absorbed in them to the exclusion of other factors; and an ultimate comprehension of the problem is usually reached when some wide generalization, including many single causes, is found.

Thus, to account for the recurring waves of commercial depression to which the modern world is a prey, the bimetallist, the protectionist, the free-trader, and other specialists, urge their pet theories as individually sufficient; while in some far-reaching chain of influences, of which these are but necessary links, is probably to be found the complete cause. What follows is as much of an attempt as so brief a space will permit to find for these phenomena a generalization of this kind.

Life, or in more general terms the persistence of any organic aggregate, depends upon adaptation to surrounding circumstances. In the animal creation this adaptation is of two fundamental descriptions: first, the development of structures for the assimilation of nutriment; and, secondly, the development of structures for the obtainment of nutriment in competition with other organisms.

In the physical struggle, which grew more intense with the multiplication of organic forms, this second mode of adaptation reached its culmination in man. Indirectly, through the use of a more developed brain, the human being so employed the forces of Nature as to overcome the teeth and claws and brawn of his 