Subtle and insubstantial, the expert leaves no trace; divinely mysterious, he is inaudible. Thus he is master of his enemy's fate.

Correct your mistake as soon as you have found it.

If you are strong, appear weak. But if you are weak, appear strong.

The sovereign must have full knowledge of the activities of the five sorts of agents. This knowledge must come from the double agents, and therefore it is mandatory that they be treated with the utmost liberality.

Factors in the art of warfare are: First, calculations; second, quantities; third, logistics; fourth, the balance of power; and fifth, the possibility of victory is based on the balance of power.

On the field of battle, the spoken word does not carry far enough; hence the institution of gongs and drums... banners and flags. Gongs and drums, banners and flags, are means whereby the ears and eyes of the host may be focused on one particular point.

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.