If the enemy opens the door, you must race in.

Without harmony in the State, no military expedition can be undertaken; without harmony in the army, no battle array can be formed.

Know the enemy, know yourself; your victory will never be endangered. Know the ground, know the weather; your victory will then be total.

To perceive victory when it is known to all is not really skilful... It does not take much strength to lift a hair, it does not take sharp eyes to see the sun and moon, it does not take sharp ears to hear the thunderclap.

So the principles of warfare are: Do not depend on the enemy not coming, but depend on our readiness against him. Do not depend on the enemy not attacking, but depend on our position that cannot be attacked.

All war is based on deception.

Opportunities increase as they are taken.