What is of the greatest importance in war is extraordinary speed: One cannot afford to neglect opportunity.

Sweat more during peace: bleed less during war

Generally in war the best policy is to take a state intact; to ruin it is inferior to this.

He who relies solely on warlike measures shall be exterminated; he who relies solely on peaceful measures shall perish.

Know thy self, know thy enemy.

The good fighters of old first put themselves beyond the possibility of defeat, and then waited for an opportunity of defeating the enemy. To secure ourselves against defeat lies in our own hands, but the opportunity of defeating the enemy is provided by the enemy himself. Thus the good fighter is able to secure himself against defeat, but cannot make certain of defeating the enemy.

If you know both yourself and your enemy, you can win a hundred battles without a single loss.