If those who are sent to draw water begin by drinking themselves, the army is suffering from thirst.

Spies are a most important element in water, because on them depends an army's ability to move.

It is according to the shapes that I lay the plans for victory, but the multitude does not comprehend this. Although everyone can see the outward aspects, none understands the way in which I have created victory.

We may distinguish six kinds of terrain, to wit: (1) Accessible ground; (2) entangling ground; (3) temporising ground; (4) narrow passes; (5) precipitous heights; (6) positions at a great distance from the enemy.

When you shoot a bow and arrow, you aim at the clouds, not because you expect to hit them, but so that you may reach the distant target on the ground.

To know your Enemy, you must become your Enemy.

Knowledge of the enemy's dispositions can only be obtained from other men.