Of all those in the army close to the commander none is more intimate than the secret agent; of all rewards none more liberal than those given to secret agents; of all matters none is more confidential than those relating to secret operations.

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?

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

Unhappy is the fate of one who tries to win his battles and succeed in his attacks without cultivating the spirit of enterprise, for the result is waste of time and general stagnation.

In the practical art of war, the best thing of all is to take the enemy's country whole and intact; to shatter and destroy it is not so good.

To ... not prepare is the greatest of crimes; to be prepared beforehand for any contingency is the greatest of virtues.

In warfare, there are no constant conditions. He who can modify his tactics in relation to his opponent will succeed and win.