By this covering it is not at all meant that a portion of the army is to be detached to defend the space round its wings, in order to prevent the enemy from approaching these weak points, as they are called: who would then defend the wings of these flanking corps? This kind of idea, which is so common, is complete nonsense. The wings of an army are in themselves not weak points of an army for this reason, that the enemy also has wings, and cannot menace ours without placing his own in jeopardy. It is only if circumstances are unequal, if the enemy’s army is larger than ours, if his lines of communication are more secure (see Lines of Communication), it is only then that the wings become weak parts; but of these special cases we are not now speaking, therefore, neither of a case in which a flanking corps is appointed in connection with other combinations to defend effectually the space on our wings, for that no longer belongs to the category of general dispositions. But although the wings are not particularly weak parts still they are particularly important, because here, on account of flanking movements the defence is not so simple as in front, measures are more complicated and require more time and preparation. For this reason it is necessary in the majority of cases to protect the wings specially against unforeseen enterprises on the part of the enemy, and this is done by placing stronger masses on the wings than would be required for mere purposes of observation. To press heavily these masses, even if they oppose no very serious resistance, more time is required, and the stronger they are the more the enemy must develop his forces and his intentions, and by that means the object of the measure is attained; what is to be done further depends on the particular plans of the moment. We may therefore regard corps placed on the wings as lateral advanced guards, intended to retard the advance of the enemy through the space beyond our wings and give us time to make dispositions to counteract his movement. If these corps are to fall back on the main body and the latter is not to make a backward movement at the same time, then it follows of itself that they must not be in the same line with the front of the main body, but thrown out somewhat forwards, because when a retreat is to be made, even without being preceded by a serious engagement, they should not retreat directly on the side of the position. From these reasons of a subjective nature, as they relate to the inner organisation of an army, there arises a natural system of disposition, composed of four or five parts according as the reserve remains with the main body or not.