The art of war does not commence with a strategical reconnaissance from the air, or the saddle, to ascertain whether, and if so in what locality and in what strength, hostile troops are being concentrated. From information so obtained, the physical force of an enemy may indeed be determined; but "in war (said Napoleon) moral force is to the physical (that is, to numbers and { 9} armament) as three to one," and upwards of a hundred years later the same idea has again been expressed. "To understand war you must go beyond its instruments and materials; you must study in the book of history, conscientiously analysed, armies, troops in movement and in action, with their needs, their passions, their devotions, their capacities of all kinds. That is the essence of the subject, that is the point of departure for a reasonable study of the art of war" (Marshal Foch). And while dealing with moral force it must be remembered that the moral force of opposing leaders of nations or of armies is at least as important as that of the nations or armies themselves, for a war is a struggle between human intelligences rather than between masses of men. "There have been soldiers' battles but never a soldiers' campaign" ("The Science of War"). "It was not the Roman legions which conquered Gaul, it was Caesar. It was not the French Army which reached the Weser and the Inn, it was Turenne" (Napoleon). A commander must, therefore, take into account the character, the moral fibre, as well as the ability and the means at the disposal of his adversary. He must project his mind to his adversary's council chamber, and putting himself in his place must conjecture how a man of that character and of that ability will act under the given circumstances.
History supplies many examples of mental activity of this kind.[2] Napoleon predicted the impetuous onset of the Russian left wing against his right at _Austerlitz_, Dec. 2, 1805, because he knew the temperament of the Tsar Alexander. At Austerlitz, the most brilliant of all his battles, Napoleon had 70,000 troops and was confronted by 80,000 Austrians and Russians drawn up on the Heights of Pratzen. His plan was to draw the weight of the Russian attack against his right--which was so disposed as to invite the headstrong and { 10} self-confident Tsar "to administer a lesson in generalship to Napoleon"--and then to launch a superior attack against the Heights, which contained a village and a knoll, the key to the position; and finally to hurl his General Reserve in a decisive counter-attack on the Russians when they were involved in battle with his right wing. When the rattle of musketry and booming of the guns showed that his right was engaged, Napoleon launched Murat, Bernadotte, and Soult against the allied centre; when Soult was master of the village and the knoll, and as the broken remnants of the enemy's centre were streaming down the reverse slopes of the Pratzen Ridge, the French centre wheeled round to the right and threw itself upon the flank and rear of the Russians, who were still heavily engaged in their original attack. These operations were completely successful and over 40,000 of the opposing armies were accounted for. Wellington defeated Soult at Sauroren in the Pyrenees (July 28, 1813) by taking advantage of a minor incident. He had ridden forward to see the disposition of the French forces, and as his men cheered him all along the line, he turned to his staff and said, "Soult is a very cautious commander. He will delay his attack to find out what those cheers mean; that will give time for the Sixth Division to arrive and I shall beat him"--and the event turned out exactly as he had predicted. Generals R. E. Lee and T. J. Jackson frequently played upon the nervousness of President Lincoln for the safety of Washington, and by threatening to cross the Potomac induced him to withdraw troops that were advancing against Richmond.