natural selection, each of which must be separately weighed and the whole then balanced, that it is a matter of extensive inquiry to determine whether a certain war has a preponderance of eugenic or dysgenic results.
When the quality of the combatants is so high, compared with the rest of the world, as during the Great War, no conceivable eugenic gains from the war can offset the losses. It is probably well within the facts to assume that the period of this war represents a decline in inherent human quality, greater than in any similar length of time in the previous history of the world.
Unfortunately, it does not appear that war is becoming much less common if we consider number of combatants rather than number of wars as times goes on,42 and it steadily tends to be more destructive. War, then, offers one of the greatest problems which the eugenist must face, for a few months of war may undo all that eugenic reforms can gain in a generation.
The total abolition of war would, of course, be the ideal, but there is no possibility of this in the near future. The fighting instinct, it must be remembered, is one of the most primitive and powerful that the human mechanism contains. It was evolved in great intensity, to give man supremacy over his environment—for the great "struggle for existence" is with the environment, not with members of one's own species. Man long ago conquered the environment so successfully that he has never since had to exert himself in physical combat in this direction; but the fighting instinct remained and could not be baulked without causing uneasiness. Spurred on by a complex set of psychological and economic stimuli, man took to fighting his own kind, to a degree that no other species