An army may be likened to water, for just as flowing water avoids the heights and hastens to the lowlands, so an army avoids strength and strikes weakness.
Defeat the enemies strategy.
One defends when his strength is inadequate, he attacks when it is abundant.
Maneuvering with an army is advantageous; with an undisciplined multitude, most dangerous.
Victory is the main object in war.
When he utilizes combined energy, his fighting men become, as it were, like rolling logs or stones... The energy developed by good fighting men is as the momentum of a round stone rolled down a mountain thousands of feet in height.