Examples of behaviour illustrating these deep differences of reaction are often to be met with in the {187} stories of those who have described incidents of the war. It is recorded that German soldiers in trenches within hearing of the English, seeking to exasperate and appal the latter, have sung in an English version their fondly valued “Hymn of Hate.” Whereupon the English, eagerly listening and learning the words of the dreadful challenge, have petrified their enemies by repeating it with equal energy and gusto, dwelling no doubt with the appreciation of experts upon the curses of their native land. It would scarcely be possible to imagine a more significant demonstration of the psychological differences of the two social types. The peculiarities of a state of the wolfish type are admirably suited to conditions of aggression and conquest, and readily yield for those purposes a maximal output of moral strength. As long as such a nation is active and victorious in war, its moral resources cannot fail, and it will be capable of an indefinite amount of self-sacrifice, courage, and energy. Take away from it, however, the opportunities of continued aggression, interrupt the succession of victories by a few heavy defeats, and it must inevitably lose the perfection of its working as an engine of moral power. The ultimate and singular source of _inexhaustible_ moral power in a gregarious unit is the perfection of communion amongst its individual members. As we have seen, this source is undeveloped in units of the aggressive type, and has been deliberately ignored by Germany. As soon, if ever, as she has to submit to a few unmistakable defeats in the field, as soon as, if it should happen, all outlets for fresh aggression are closed, she will become aware of how far she has staked her moral resources on continuous success, and will not be able for long to conceal her knowledge from the world. {188}