Against those skilled in attack, an enemy does not know where to defend; against the experts in defense, the enemy does not know where to attack.

Unless you know the mountains and the forests, the defiles and impasses, the lay of the marshes and swamps, you cannot maneuver with an armed force. Unless you use local guides, you cannot get the advantages of the land.

Hostile armies may face each other for years, striving for the victory which is decided in a single day. This being so, to remain in ignorance of the enemy's condition simply because one grudges the outlay of a hundred ounces of silver in honors and emoluments, is the height of inhumanity.

If ignorant both of your enemy and yourself, you are certain to be in peril.

The successful person has unusual skill at dealing with conflict and ensuring the best outcome for all.

Know thy self, know thy enemy.

When your opponent gives you an opening, be swift as a hare.