Convince your enemy that he will gain very little by attacking you; this will diminish his enthusiasm

Quickness is the essence of the war.

In warfare, there are no constant conditions. He who can modify his tactics in relation to his opponent will succeed and win.

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

In executing an Artful Strategy: When ten times greater, surround them; When five times greater, attack them; When two times greater, scatter them. If the opponent is ready to challenge: When fewer in number, be ready to evade them; When unequal to the match, be ready to avoid them. Even when the smaller opponents have a strong position, the larger opponent will capture them.

It is a doctrine of war not to assume the enemy will not come, but rather to rely on one's readiness to meet him; not to presume that he will not attack, but rather to make one's self invincible.

Of all those in the army close to the commander none is more intimate than the secret agent; of all rewards none more liberal than those given to secret agents; of all matters none is more confidential than those relating to secret operations.