The end and aim of spying in all its five varieties is knowledge of the enemy; and this knowledge can only be derived, in the first instance, from the converted spy. Hence it is essential that the converted spy be treated with the utmost liberality.

He whose ranks are united in purpose will be victorious.

Spies cannot be usefully employed without a certain intuitive sagacity; They cannot be properly managed without benevolence and straightforwardness; Without subtle ingenuity of mind, one cannot make certain of the truth of their reports; Be subtle! be subtle! and use your spies for every kind of warfare; If a secret piece of news is divulged by a spy before the time is ripe, he must be put to death together with the man to whom the secret was told.

The best victory is when the opponent surrenders of its own accord before there are any actual hostilities...It is best to win without fighting.

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.

Act after having made assessments. The one who first knows the measure of far and near wins - this is the rule of armed struggle.

All wars are won or lost before they are ever fought.