To this Napoleon[377] replied from St. Helena:
“The question in this battle was not that of separating the English from the Prussians; we knew that the English could not be ready to act till the next day; but here the point was to hinder that part of the IIId Corps of Blücher which had not joined him by 11 A.M., and which came by way of Namur, and also the IVth Corps, which came from Liége by way of Gembloux, from uniting [with the Ist and IId Corps] on the field of battle. In cutting the enemy’s line at Ligny, his whole right wing at St. Amand was turned and compromised; while by simply becoming masters of St. Amand, we should have accomplished nothing.”
In other words, Napoleon defends his plan of battle by showing that it aimed at a decisive tactical success; that its accomplishment would practically have destroyed half of the Prussian army; which an attack upon the exposed right wing would not have effected. He contends that the Prussians being, as they certainly were, on this day, completely separated from the English, the best thing he could possibly do was to take advantage of their faulty formation, and cut off and destroy the two exposed corps. This he calculated he could effect with the troops he had in hand. Then he undoubtedly hoped that he would get assistance from Ney in this operation.[378] The order to Ney at 2 P.M. shows this beyond a question; and this order was reiterated at a quarter-past three. Napoleon said to Gérard during the battle,[379] “It is possible that in three hours the issue of the war may be decided. If Ney executes his orders well, not a cannon in the Prussian army can escape capture. That army is taken en flagrant délit.” This last expression occurs also in the 3.15 P.M. order. The possibility of Ney’s sending a force down the Quatre-Bras-Namur turnpike to take the exposed Prussian right wing in rear, was therefore an additional reason for inclining him to make his main attack at Ligny, and thereby isolate this wing, with the hope of surrounding and destroying it. That he had no right to count on Ney’s coöperation is certainly true, as has been stated above; but then Napoleon believed that he could carry out his plan without Ney’s coöperation, and that if Ney should assist him, his success would be overwhelming.
To the reasons advanced by Rogniat for making the main attack upon the right flank of the Prussians, Marshal Davout adds another:—[380]
“He ought not to have left the Prussian army between himself and Marshal Ney; because, in that case, if he should beat the Prussians, he would force them to retire in the direction of the English.”
To the same effect Clausewitz[381] asks, “whether Bonaparte ought to have arranged his attack so as to drive Blücher towards Wellington, or so as to push him away from him,”—implying that the result of the battle as fought by Napoleon had the former effect.
“If,” says Clausewitz, “Bonaparte had attacked St. Amand with his right wing, Wagnelée with his left, and had advanced with a third column against the road from Brussels,[382] the Prussians, if they lost the battle, would have been forced to retreat along the Roman road, that is, towards the Meuse, and a union with Wellington in the days immediately following the battle would have been very uncertain, perhaps impossible.”
We can have no hesitation in admitting that if the Prussians had been driven in the direction of the Meuse as the result of the battle, they could not have afforded aid to the English on the 18th of June. But we can hardly believe that if Napoleon had destroyed their Ist and IId Corps, which he expected would be the result of his plan of battle, the Prussians could possibly have afforded any further assistance to the English. Still, while the decision of the Prussian generals after the battle to maintain their communication with the Duke of Wellington, and to come to his assistance at Waterloo with their whole army, was not arrived at merely or chiefly because the two corps which had been beaten at Ligny were able to fall back in a northerly direction instead of in an easterly direction, in retiring from the field of battle,[383] it is certainly true that this fact did make the task easier of accomplishment; it saved time, also. At the same time, it did not affect in any way the risk involved in the operation,—that of renouncing for the time being their line of supplies.
3. We have seen that Napoleon believed that Ney’s intervention, which, as we have seen, might have occurred at the moment when the Prussian centre was being pierced, would have gained him a great victory. But Clausewitz[384] asks: “Why was it inevitable that 10,000 men in the rear of the strong Prussian army of 80,000 men, in an open country, where one can see on all sides, should bring about its complete overthrow?” In other words, Napoleon was not warranted (so Clausewitz contends) in expecting such a decisive success, even if Ney should send 10,000 men down the Namur road.