The unpleasant truth should be realized that invading armies must, with other luxuries, have women. As a result, they leave a large progeny--wrens in the nests of the doves of peace. Hence, inasmuch as soldiers are the pick of the manhood of their country, they are likely to do about as much toward securing the survival of the fit in an enemy's country as they would have in their own country.
There is another very important consideration, which is that war is a great mixer of races, and that usually mixed types benefit enormously from their compound blood.
Furthermore, the mingling of races and peoples has in all times served greatly to spread knowledge of one another, and they have always profited largely from the mingled knowledge. Soldiers visiting distant lands have brought home acquaintance with new arts and sciences and broader ideas of international usefulness. The soldiers of the North, who marched with Sherman through Georgia to the sea, returned years afterward and built cotton mills, iron foundries, and machine-shops all over the South, and stimulated the South with Northern energy and Northern capital.
We know that the inhabitants of the earth are constantly growing more fit; consequently, we know that they cannot be growing constantly more unfit, due to the degenerative influence of war. The history of nations is a history of wars; consequently we know as untrue the contention of the peace sophists that war secures the survival of the unfit. We know that exactly the opposite must be true; that war secures the survival of the fit.
There is yet another thing of which the peace sophists have never thought, and could not be expected to think--the tremendous self-saving potentiality of the race.
As I have pointed out elsewhere, Nature seems to care little for individuals, but everything for a race or species; consequently, Nature has forefended herself by very ample measures to insure the survival of the fit.
If every able-bodied man in the world today were to be slain, and only the weak and puny left, although the injury would be incalculable and would make the whole race stagger, still the next generation of men would be almost as able-bodied and as fit as the present generation. Let us see why: It is because of that great potentiality--atavism. Children inherit not only directly from their parents, but their inheritance harks back to grandfather, great-grandfather, and even to remote ancestry.