It is ten thousand times cheaper to pay the best spies lavishly than even a tiny army poorly.

O divine art of subtlety and secrecy!

First learn to become invincible, then wait for your enemy's moment of vulnerability.

Like the sun and moon, they end but to begin anew; like the four seasons, they pass away to return once more.

If fighting is sure to result in victory, then you must fight, even though the ruler forbid it; if fighting will not result in victory, then you must not fight even at the ruler's bidding.

A military operation involves deception. Even though you are competent, appear to be incompetent. Though effective, appear to be ineffective.

Should the enemy forestall you in occupying a pass, do not go after him if the pass is fully garrisoned, but only if it is weakly garrisoned.