Emptiness and Fullness — Chapter Six

Sun Tzu said: Those who occupy the ground of battle before the enemy arrives are at ease; those who take the ground later and must hurry to battle are fatigued. Therefore the skillful commander causes others to come to him and does not go to others.

To make the enemy come of their own accord is to offer them profit; to prevent the enemy from coming is to harm them. Thus make the idle enemy labor, make the sated enemy hungry, make the secure enemy move. Move where they do not expect to go; strike where they do not expect to be struck.

To march a thousand li without fatigue is to move through ground unoccupied by men. To attack and be sure to capture is to strike where he does not guard; to defend and be sure to hold is to defend where he does not attack. Therefore the skillful attacker makes the enemy uncertain where to guard; the skillful defender makes the enemy uncertain where to attack. Subtle, subtle indeed — reaching formlessness; mysterious, mysterious indeed — reaching soundlessness. Thus one can determine the enemy’s fate.

Advance in a way that cannot be stopped by striking at their weak points; withdraw in a way that cannot be pursued by moving with speed beyond reach. Thus, if I desire battle, even though the enemy has high ramparts and deep ditches, I can force him to fight by attacking what he must relieve. If I desire not to fight, even if I merely mark out ground and hold it, I can prevent the enemy from engaging by diverting his intentions.

Therefore give the enemy a visible form while I remain formless; then I concentrate while the enemy disperses. I concentrate as one, the enemy divides into ten; when ten attack one, I am many and the enemy few. He who can use many against few makes his engagements sure. If the place where I will fight cannot be known, then the enemy must prepare in many places; with many places to prepare, the place I fight will be thinly guarded. Prepare the front and the rear will be weak; prepare the rear and the front will be weak; prepare the left and the right will be weak; prepare the right and the left will be weak. If you prepare everywhere, then nothing is weak. 'Weak' means being the one forced to guard; 'many' means making others guard against you.

Therefore, knowing where to fight and when to fight allows you to gather forces over a thousand li for battle; not knowing where or when means the left cannot help the right, the right cannot help the left, the front cannot help the rear, and the rear cannot help the front — and that is with distances of only a few li, much less dozens. In my judgment, though the Yue may have many soldiers, how much does that avail in victory or defeat? Hence it is said: victory can be seized. Even if the enemy is numerous, he can be rendered unable to fight.

Thus by calculation you know the measures of gain and loss; by disposition you know the principles of movement and stillness; by forming shape you know the ground of life and death; by probing you discover surplus and deficiency. Therefore the extreme in shaping an army is to be formless. Formless, the deepest spy cannot see it, the wisest cannot plan against it. By adapting form to secure victory, the many cannot know. All may know the apparent forms by which I win, but none know the underlying forms by which I control victory. Therefore my triumphs cannot be repeated in the same way; I shape myself endlessly to circumstances.

The shape of an army is like water. The way water moves is to avoid heights and flow downward; the army that wins avoids the strong and strikes the weak. Water shapes its course to the ground; army shapes victory to the enemy. Hence an army has no constant form, no fixed shape; one who can change with the enemy to secure victory is called divine. Likewise the five elements have no permanent victor, the four seasons have no fixed place: days are short or long, the moon wanes and waxes.