It is not contended that the system here described is perfect. Every system has its failures, and there is no possibility of entirely excluding the influences of favour or prejudice. But it may be asserted with confidence that the high average of practical ability secured in the superior officers of the Prussian army is due in the main to the practice of selection, the careful inspection by the superiors, at every stage, and to the mature wisdom by which the higher education of the general staff is directed. The intellectual advancement of the officers of every army is confronted by a peculiar difficulty. The foundations of all military institutions are authority and obedience--principles which appear to be directly opposed to the free movement of intelligence. Every army is constantly in danger of decay from mental stagnation. Free criticism is liable to undermine discipline, and the habit of unconditional obedience too often destroys the independence of judgment without which moral and intellectual progress is impossible. The Prussian general staff has escaped from this dilemma by itself taking the lead in scientific progress, and organizing itself, in regard to all that concerns the business of national defence, as an institution for the advancement of learning. [1] Cf. Colonel Maurice in the _Encyclopedia Britannica_ article "War," p. 345: "There does not exist, and never has existed ... an 'art of war' which was something other than the methodic study of military history." [2] It is interesting to note that Moltke was a pupil at the War Academy from 1823 to 1826, while Clausewitz was its director. The director, however, is not a teacher, and Clausewitz did not publish any of his principal works during his lifetime, so that the evidence does not prove a personal influence of Clausewitz upon Moltke. [3] See Vom Kriege, _Hinterlassenes Werk des Generals Carl von Clausewitz_, Zweites Buch, Fünftes Capitel. [4] Clausewitz is fully aware of the difficulty with which this critical study has to contend, that the real causes, the motives which led to the adoption of a particular measure, are in many cases unknown. [5] It may be interesting to compare with what follows Foster's _Essay on Decision of Character_, Letter VI., in which the value of a "conclusive manner of thinking" is discussed.