It is essential to seek out enemy agents who have come to conduct espionage against you and to bribe them to serve you. Give them instructions and care for them. Thus doubled agents are recruited and used.

Know thy self, know thy enemy. A thousand battles, a thousand victories.

What enables the wise sovereign and the good general to strike and conquer, and achieve things beyond the reach of ordinary men, is foreknowledge.

A sovereign of high character and intelligence must be able to know the right man, should place the responsibility on him, and expect results.

In peace prepare for war, in war prepare for peace. The art of war is of vital importance to the state. It is matter of life and death, a road either to safety or to ruin. Hence under no circumstances can it be neglected.

What is of the greatest importance in war is extraordinary speed: One cannot afford to neglect opportunity.

The peak efficiency of knowledge and strategy is to make conflict unnecessary.