If our soldiers are not overburdened with money, it is not because they have a distaste for riches; if their lives are not unduly long, it is not because they are disinclined to longevity.
Those who do not know the plans of competitors cannot prepare alliances. Those who do not know the lay of the land cannot maneuver their forces. Those who do not use local guides cannot take advantage of the ground.
From a position of this sort, if the enemy is unprepared, you may sally forth and defeat him. But if the enemy is prepared for your coming, and you fail to defeat him, then, return being impossible, disaster will ensue.
These are the six ways of courting defeat - neglect to estimate the enemy's strength; want of authority; defective training; unjustifiable anger; nonobservance of discipline; failure to use picked men.
In your deliberations, when seeking to determine the military conditions, let them be made the basis of a comparison, in this wise: which of the two generals has the most ability? on which side is Discipline most rigorously enforced? which army is stronger? on which side are the officers and men more highly trained? in which army is there the greater constancy both in reward and punishment?
The art of war teaches us to rely not on the likelihood of the enemy's not coming, but on our own readiness to receive him; not on the chance of his not attacking, but rather on the fact that we have made our position unassailable.