- trolling factors which, in map problems, do not appear at all,
and which, in exercises on the terrain, appear only in a restricted measure. One must learn the conduct of war from the experience of others; one's own experience is costly and is almost invariably gained too late. That experience in war, of itself, is not sufficient (aside from the fact that it is gained too late in a given case) is illustrated by the defeat of the Austrians in 1866, of the French in 1870-71, and of the British in South Africa. "Les Autrichiens," says Colonel Foch,[1] "ont fait la guerre sans le comprendre, les Prussiens l'ont compris sans le faire, mais ils l'ont étudiée." "Military history is neither a compilation of clever theories nor a book designed for whiling away idle moments. It is, on the contrary, a careful teacher, who, if we are attentive, allows us to view and grasp matters which we have never before been in a position to see, but which, nevertheless, are liable to confront us in the same, a similar, or a changed form, and demand unpremeditated, instant and decisive action, entailing heavy responsibilities. Military history, it is true, offers us, in the first instance, only events and their outline, conditions and phenomena, but it also presents, what the cleverest theory is unable to furnish, a graphic illustration of the disturbing elements in war, an illustration of the influences, doubts, embarrassments, unforeseen accidents, surprises and delays. It describes the course pursued by commanders and by practical military common sense in surmounting these difficulties. It prepares in advance the mental balance necessary at the moment of action; it should prepare also for the unexpected. It affords a substitute for lack of military experience, for the accumulation of which the life of the individual, prior to the moment of action, has been too short."[2] The pedantic enumeration of a few examples in support of a stated opinion can-*
