In view of the development of modern technical science, it was inevitable that the World War should exhibit many characteristics different from those of earlier wars. None the less, it would be a great error to declare all the experience gained from previous wars to be out of date. The human intelligence attaches itself involuntarily to what lies nearest. Those who turned to account the experiences of the Boer War and of the Manchurian campaign would have benefited by a warning against one-sidedness. We have already drawn attention to the fact that, notwithstanding the power and effectiveness of modern weapons, now as ever it is the moral element that is finally decisive in war. The same is true of the intellectual element, of leadership. If the leaders were unwilling to consult the experiences of earlier wars, they would fall into a hopeless one-sidedness. As in every department of practical life, it is a question of finding the true relation between knowledge and capacity. Clausewitz expresses it exactly when he says[1]: "He who intends to move in such an element as war must bring with him nothing at all gained from books save the education of his mind; if he brings with him ready-made ideas which have not been inspired in him by the shock of the moment, which he has not generated out of his own flesh and blood, the rush of events will overthrow his building before it is completed. He will never be understood by natural men and will enjoy least confidence precisely among the most distinguished of them, that is to say, those who know themselves what they want." Thus the instruction gained from the past must be further developed and adapted to present-day conditions. This was done for his age by Moltke in exemplary fashion. When he became the Chief of the General Staff he was already advanced in years, and although he possessed abundant practical experience and a comprehensive technical training, he had had no experience of European wars on a large scale. Hence he derived his opinions inevitably from the Napoleonic wars, and he could do so without detriment. The masses of troops which he had subsequently to command were no larger than the armies of the last wars of the First Empire. The army corps of 1866 and 1870 still corresponded to some extent to what to-day has already reached the dimensions of an army or army-group. Moreover, the difference between the military weapons of Moltke's day and those of the previous Napoleonic era was less than the difference between those of our day and those of 1870, though the introduction of breechloaders and rifled barrels had even at that day marked an important advance in the technique of arms, and Moltke did in fact form a just estimate of their influence upon tactics.