If the ground and occasion be not known, the front cannot help the rear; the left cannot support the right, nor the right the left, nor the rear the front. For on occasion, the parts of the army are two score leagues apart, while a distance of four or five leagues is comparatively close. The soldiers of Wu[10] are less than the soldiers of Yueh; but as superiority in numbers does not of necessity bring victory, I say, then, that we may obtain the victory. If the enemy be many in number, prevent him from taking advantage of his superiority, and ascertain his plan of operations. Provoke the enemy and discover the state of his troops; feint and discover the strength of his position. Flap the wings, and unmask his sufficiency or insufficiency. By constant feints and excursions, we may produce on the enemy an impression of intangibility, which neither spies nor art can dispel. The general makes his plans in accordance with the dispositions of the enemy, and puts his hosts in motion; but the multitude cannot appreciate the general's intention; they see the signs of victory, but they cannot discover the means. If a victory be gained by a certain stratagem, do not repeat it. Vary the stratagem according to circumstances. An army may be likened to water. Water leaves dry the high places, and seeks the hollows. An army turns from strength and attacks emptiness. The flow of water is regulated by the shape of the ground; victory is gained by acting in accordance with the state of the enemy. The shape of water is indeterminate; likewise the spirit of war is not fixed. The leader who changes his tactics in accordance with his adversary, and thereby controls the issue, may be called the God of war. Among the five elements[11] there is no settled precedence; the four seasons come and go; the days are long and short; and the moon waxes and wanes. _So in war there is no fixity._ VII BATTLE TACTICS Sun the Master said:-- For the most part, military procedure is as follows:-- The general receives orders from his lord; assembles and settles harmony among the forces, and takes the field. There is nothing more difficult than Battle Tactics. Their difficulty lies in the calculation of time and distance, and the reversal of misfortune. To make the enemy take a circuitous route by a show of gain, and then, whilst starting after him, to arrive before him, is to be a master of the art of manoeuvre. The operations of an army may reap advantage; the wrangles of a multitude are fraught with peril.