We are to-day forced to undertake a more searching inquiry into the forces which, in civilisation, operate against war. I wish to call attention here to one such influence of fundamental character, which has not been unrecognised, but possesses an importance we are often apt to overlook. "A French gentleman, well acquainted with the constitution of his country," wrote Thicknesse in 1776,[1] "told me above eight years since that France increased so rapidly in peace that they must necessarily have a war every twelve or fourteen years to carry off the refuse of the people." Recently a well-known German Socialist, Dr. Eduard David, member of the Reichstag and a student of the population question, setting forth the same great truth (in _Die Neue Generation_ for November, 1914) states that it would have been impossible for Germany to wage the present war if it had not been for the high German birth-rate during the past half-century. And the impossibility of this war would, for Dr. David, have been indeed tragic. A more distinguished social hygienist, Professor Max Gruber, of Munich, who took a leading part in organising that marvellous Exposition of Hygiene at Dresden which has been Germany's greatest service to real civilisation in recent years, lately set forth an identical opinion. The war, he declares, was inevitable and unavoidable, and Germany was responsible for it, not, he hastens to add, in any moral sense, but in a biological sense, because in forty-four years Germans have increased in numbers from forty millions to eighty millions. The war was, therefore, a "biological necessity." If we survey the belligerent nations in the war we may say that those which took the initiative in drawing it on, or at all events were most prepared to welcome it, were Russia, Austria, Germany, and Serbia. We may also note that these include nearly all the nations in Europe with a high birth-rate. We may further note that they are all nations which--putting aside their cultural summits and taking them in the mass--are among the most backward in Europe; the fall in the birth-rate has not yet had time to permeate them. On the other hand, of the belligerent peoples of to-day, all indications point to the French as the people most intolerant, silently but deeply, of the war they are so ably and heroically waging. Yet the France of the present, with the lowest birth-rate and the highest civilisation, was a century ago the France of a birth-rate higher than that of Germany to-day, the most militarist and aggressive of nations, a perpetual menace to Europe. For all those among us who have faith in civilisation and humanity, and are unable to believe that war can ever be a civilising or humanising method of progress, it must be a daily prayer that the fall of the birth-rate may be hastened.