It is fairly safe to assume that there will be very little new furniture on the stage of the world for some considerable time; that if there is much difference in the roads and railways and shipping it will be for the worse; that architecture, domestic equipment, and so on, will be fortunate if in 1924 they stand where they did in the spring of 1914. In the trenches of France and Flanders, and on the battlefields of Russia, the Germans have been spending and making the world spend the comfort, the luxury and the progress of the next quarter-century. There is no accounting for tastes. But the result is that, while it was possible for the writer in 1900 to write "Anticipations of the Reaction of Mechanical Progress upon Human Life and Thought," in 1916 his anticipations must belong to quite another system of consequences. The broad material facts before us are plain enough. It is the mental facts that have to be unravelled. It isn't now a question of "What thing--what faculty--what added power will come to hand, and how will it affect our ways of living?" It is a question of "How are people going to take these obvious things--waste of the world's resources, arrest of material progress, the killing of a large moiety of the males in nearly every European country, and universal loss and unhappiness?" We are going to deal with realities here, at once more intimate and less accessible than the effects of mechanism. As a preliminary reconnaissance, as it were, over the region of problems we have to attack, let us consider the difficulties of a single question, which is also a vital and central question in this forecast. We shall not attempt a full answer here, because too many of the factors must remain unexamined; later, perhaps, we may be in a better position to do so. This question is the probability of the establishment of a long world peace. At the outset of the war there was a very widely felt hope among the intellectuals of the world that this war might clear up most of the outstanding international problems, and prove the last war. The writer, looking across the gulf of experience that separates us from 1914, recalls two pamphlets whose very titles are eloquent of this feeling--"The War that will End War," and "The Peace of the World." Was the hope expressed in those phrases a dream? Is it already proven a dream? Or can we read between the lines of the war news, diplomatic disputations, threats and accusations, political wranglings and stories of hardship and cruelty that now fill our papers, anything that still justifies a hope that these bitter years of world sorrow are the darkness before the dawn of a better day for mankind? Let us handle this problem for a preliminary examination.