It is also true,[373] that, had Napoleon advanced early in the morning with the main body of his army, leaving Ney to push forward with the left wing as soon as he could, he would have been able to interrupt the formation of the Prussian line of battle, and would not have been in the least interfered with by the Anglo-Dutch army. But Napoleon, although it is plain from his letters to Grouchy and Ney that he did not expect to find either the Prussians or the English in great force, preferred on the whole to make his own advance coincide in point of time with that of Marshal Ney. He could not estimate with any certainty the number of troops which Blücher might have on the heights of Ligny or within call; he could not know how large a part of his army Wellington had been able to collect. Hence he decided to defer his own movement until Ney was ready, or, at least, ought to have been ready, with all the troops which had been assigned to him, to protect the left flank of the main army from all danger of an attack by the Anglo-Dutch forces. The question is one on which different opinions will always exist. The course adopted by Napoleon was unquestionably the one most in accordance with the principles of war. Whether a chance of success justifies a departure from the practice of those principles, or whether such a departure is warranted only in cases of emergency, is the real question. We have no room to discuss it further here. 2. Napoleon’s plan of battle at Ligny has been severely criticised. Clausewitz,[374] Rogniat,[375] Marshal Davout,[376] are especially pronounced in their opinion that Napoleon should have manœuvred so as to turn the Prussian right, and not to pierce their centre. The question is thus stated by Rogniat: “We arrived upon their right flank; reason counselled us to attack this wing; in this way we should have avoided in part the defiles of the brook; we should have approached our own left wing, which was fighting at Quatre Bras, so that both armies could have helped each other, and finally we should have thrown the Prussians far from the English, in forcing them to retire on Namur.” 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.”