Of the value of du Picq's work to the professional soldier, I naturally cannot speak, but even for the civilian, the student of military events, of war and of the larger as well as the smaller circumstances of battle, its usefulness can hardly be exaggerated. Reading it one understands something, at least of the soul as well as the science of combat, the great defeats and the great victories of history seem more intelligible in simple terms of human beings. Beyond this lies the contemporaneous value due to the fact that nowhere can one better understand Foch than through the reading of du Picq. By translating this volume of du Picq and thus making it available for an American audience whose interest has been inevitably stirred by recent events, the translators have done a public as well as a professional service. Both officers enjoyed exceptional opportunities and experiences on the Western front. Col. Greely from Cantigny to the close of the battle of the Meuse-Argonne was not only frequently associated with the French army, but as Chief of Staff of our own First Division, gained a direct knowledge of the facts of battle, equal to that of du Picq, himself. On the professional side the service is obvious, since before the last war the weakness of the American like the British Army, a weakness inevitable, given our isolation, lay in the absence of adequate study of the higher branches of military science and thus the absence of such a body of highly skilled professional soldiers, as constituted the French or German General Staff. The present volume is a clear evidence that American officers themselves have voluntarily undertaken to make good this lack. On the non-professional side and for the general reader, the service is hardly less considerable, since it supplies the least technically informed with a simply comprehensible explanation of things which almost every one has struggled to grasp and visualize during the last six years extending from the battle of Marne in 1914 to that of the Vistula in 1920. Of the truth of this latter assertion, a single example will perhaps suffice. Every forthcoming military study of the campaign of 1914 emphasizes with renewed energy the fact that underlying all the German conceptions of the opening operations was the purpose to repeat the achievement of Hannibal at Cannae, by bringing the French to battle under conditions which should, on a colossal scale, reproduce those of Hannibal's greatest victory. But nowhere better than in du Picq's volume, are set forth the essential circumstances of the combat which, after two thousand years gave to Field Marshal von Schlieffen the root ideas for the strategy expressed in the first six weeks of 1914. And, as a final observation, nowhere better than in du Picq's account, can one find the explanation of why the younger Moltke failed in executing those plans which gave Hannibal one of the most shining triumphs in all antiquity.