IV: Formation
In ancient times skillful warriors first made themselves invincible, and
then watched for vulnerability in their opponents.
Invincibility is in oneself, vulnerability is in the opponent.
Therefore skillful warriors are able to be invincible, but they cannot cause opponents to be vulnerable.
That is why it is said that victory can be discerned but not manufactured.
Invincibility is a matter of defense, vulnerability is a matter of attack.
Defense is for times of unsufficiency, attack is for times of surplus.
Those skilled in defense hide in the deepest depths of the earth, those skilled in attack maneuver in the highest heights of the sky. Therefore they can preserve themselves and achieve complete victory.
To perceive victory when it is known to all is not really skillful. Everyone calls victory in battle good, but it is not really good.
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 a thunderclap.
In ancient times those known as good warriors prevailed when it was easy to prevail.
Therefore the victories of good warriors are not noted for cleverness or bravery. Therefore their victories in battle are not flukes. Their victories are not flukes because they position themselves where they will surely win, prevailing over those who have already lost.
So it is that good warriors take their stand on ground where they cannot lose, and do not overlook conditions that make an opponent prone to defeat.
Therefore a victorious army first wins and then seeks battle; a defeated army first battles and then seeks victory.
Those who use arms well cultivate the Way and keep the rules. Thus they can govern in such a way as to prevail over the corrupt.
The rules of the military are five: measurement, assessment, calculation, comparison, and victory. The ground gives rise to measurements, measurements give rise to assessments, assessments give rise to calculations, calculations give rise to comparisons, comparisons give rise to victories.
Therefore a victorious army is like a pound compared to a gram, a defeated army is like a gram compared to a pound.
When the victorious get their people to go to battle as if they were directing a massive flood of water into a deep canyon, this is a matter of formation.