(2) But the moral harm of war is no less conspicuous than the physical.  It fosters cruelty, callousness, contempt of life; it kills sympathy and the gentler virtues; it coarsens and leads almost inevitably to sensuality.  After a war there is always a marked increase in crime and sexual vice; ex-soldiers are restless, and find it hard to settle down to a normal life.  There is a permanent coarsening of fiber.  Even the maintenance of armies in time of peace is a great moral danger.  The unnatural barrack-life, the requisite postponement of marriage, the opportunity for physical and moral contagion, make military posts commonly sources of moral contamination.  Prostitution flourishes and illegitimacy increases where soldiers are quartered; the army is a bad school of morals.

Add to this indictment the stimulus to national hatreds caused by war, the inflaming of resentments and checking of international good will.  Frenchmen still nourish a bitter animosity against the Germans for the possession of Alsace and the occupation of Paris.  The instinctive racial antipathies of the Balkan peoples have been immeasurably deepened by the recent wars on the peninsula.  The eventual brotherhood of man is indefinitely postponed by every war and by every rumor of war.

The interest in war also takes attention and effort away from the remedying of social and moral evils; it is useless to attempt any moral campaign while a war is on.  Jane Addams tells us, in Twenty Years at Hull House, that when she visited England in 1896 she found it full of social enthusiasm, scientific research, scholarship, and public spirit; while on a second visit, in 1900, all enthusiasm and energy seemed to be absorbed by the Boer War, leaving little for humanitarian undertakings.

(3) A less obvious, but even more lasting, evil is that caused by the loss of the best blood of a nation.  In general, the strongest and best men go to the field; the weaklings and cowards are left to produce the next generation.  The inevitable result is racial degeneration.  The decline of the Greek and Roman civilizations was doubtless in large part due to the continual killing off of the best stocks, until the earlier and nobler breed of men almost ceased to exist.  The effect of modern war is the exact opposite of that of primitive war, where all the men had to fight, and the strongest or bravest or swiftest survived; strength and valor and speed avail nothing against modern projectiles, and it is the stay-at-homes who are selected for survival, in general the weakest and least worthy.  War is the greatest of dysgenic forces, and undoes the effect of a hundred eugenic laws.