But although we assume that each of these distinct parts of an army shall be competent to undertake an independent combat, and it may be obliged to engage in one, it does not therefore by any means follow that the real object of fractioning an army is that the parts should fight separately; the necessity for this distribution of the army is mostly only a condition of existence imposed by time. If the enemy approaches our position to try the fate of a general action, the strategic period is over, everything concentrates itself into the one moment of the battle, and therewith terminates and vanishes the object of the distribution of the army. As soon as the battle commences, considerations about quarters and subsistence are suspended; the observation of the enemy before our front and on our flanks has fulfilled the purpose of checking his advance by a partial resistance, and now all resolves itself into the one great unit—the great battle. The best criterion of skill in the disposition of an army lies in the proof that the distribution has been considered merely as a condition, as a necessary evil, but that united action in battle has been considered the object of the disposition. CHAPTER VII. Advanced Guard and Out-Posts These two bodies belong to that class of subjects into which both the tactical and strategic threads run simultaneously. On the one hand we must reckon them amongst those provisions which give form to the battle and ensure the execution of tactical plans; on the other hand, they frequently lead to independent combats, and on account of their position, more or less distant from the main body, they are to be regarded as links in the strategic chain, and it is this very feature which obliges us to supplement the preceding chapter by devoting a few moments to their consideration. Every body of troops, when not completely in readiness for battle, requires an advanced guard to learn the approach of the enemy, and to gain further particulars respecting his force before he comes in sight, for the range of vision, as a rule, does not go much beyond the range of firearms. But what sort of man would he be who could not see farther than his arms can reach! The foreposts are the eyes of the army, as we have already said. The want of them, however, is not always equally great; it has its degrees. The strength of armies and the extent of ground they cover, time, place, contingencies, the method of making war, even chance, are all points which have an influence in the matter; and, therefore, we cannot wonder that military history, instead of furnishing any definite and simple outlines of the method of using advanced guards and outposts, only presents the subject in a kind of chaos of examples of the most diversified nature.