When one thinks of the myriads of minute living organisms that pervade and make up his own body, of their struggles and activities, their antagonisms and coöperations, their victories and defeats,--the cells coöperating and building up the organs, the organs coöperating and building up the body, the phagocytes policing the blood and destroying the invading germs, the intestinal flora contending with one another for the possession of the soil, the ferments, the enzymes,--when one thinks of all this and more, and how little aware the man is of all this strife and effort and activity within him,--how he himself, body and mind, is the result of it all,--one has a dim vision of all our strife and effort in this world as a part of the vital movements of a vast system of things, or of a Being that is no more cognizant of our wars and struggles and triumphs than we are of the histories of the little people that keep up the functional integrity of our own systems. Man can himself make short work of the ants unless he encounters their devouring hosts in a tropical jungle, in which case they may make short work of him. He can often slay with his antiseptics the disease-germs that are destroying him, but not always; the balance of nature is often on their side. Whichever triumphs, Nature wins, because all are parts of her system. The capital invested is hers alone. Man thinks a part of it is his, because he forgets that he too is a part of Nature, and that whatever is his, is hers. How are we to reconcile the obvious facts of evolution, namely, that throughout the biological ages there has been an impulse in Nature steadily working toward the development of man, with the still more obvious fact that Nature cares no more for the individual man than she does for the individual of any other species? She will drown him, starve him, freeze him, crush him, as quickly as she will any other form of life. Is the account balanced by the fact that she has given him the wit and the power to avoid these calamities in a larger measure than she has given them to any other creature? That is the way the great mystery works. Every creature is exposed to the hazards of its kind, but within its reach are always the benefits and advantages of its kind, and these latter have steadily kept in the lead. The evolutionary impulse toward the horse, toward the dog, toward the bird, has apparently been as jealously guarded and promoted as the impulse toward man. Man in his own conceit is at the head of the animal kingdom, and the whole creation is for him, though there are other animals that surpass him in strength, speed, and endurance. But he alone masters and makes servants of the inorganic forces, and thus rules the world below him.