Fighting with a large army under your command is nowise different from fighting with a small one: it is merely a question of instituting signs and signals.

So there are five ways of knowing who will win. Those who know when to fight and when not to fight are victorious. Those who discern when to use many or few troops are victorious. Those whose upper and lower ranks have the same desire are victorious.

Therefore I say: know the enemy and know yourself; in a hundred battles you will never be in peril. When you are ignorant of the enemy but know yourself, your chances of winning or losing are equal. If ignorant both of your enemy and of yourself, you are certain in every battle to be in peril.

The relative size of your force as against that of your adversary is by itself of no consequence. What controls is the relative size of your force at the point where you join in battle. You can strike with the few and be many if you strike your adversary in his gaps. Seek out places where the defense is not strict, the place not tightly guarded, the generals weak, the troops disorderly, the supplies are scarce and the forces are isolated.

There are not more than five primary colours, yet in combination they produce more hues than can ever been seen.

Fierce language and pretentious advances are signs that the enemy is about to retreat.

Now this foreknowledge cannot be elicited from spirits; it cannot be obtained inductively from experience, nor by any deductive calculation.