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 ca… - Sun Tzu

About Sun Tzu himself this is all that Ssu-ma Ch`ien has to tell us in this chapter. But he proceeds to give a biography of his descendant, Sun Pin, born about a hundred years after his famous ancestor's death, and also the outstanding military genius of his time.

The difficulty of tactical maneuvering consists in turning the devious into the direct, and misfortune into gain. [This sentence contains one of those highly condensed and somewhat enigmatical expressions of which Sun Tzu is so fond. This is how it is explained by Ts’ao Kung: “Make it appear that you are a long way off, then cover the distance rapidly and arrive on the scene before your opponent.” Tu Mu says: “Hoodwink the enemy, so that he may be remiss and leisurely while you are dashing along with utmost speed.” Ho Shih gives a slightly different turn: “Although you may have difficult ground to traverse and natural obstacles to encounter this is a drawback which can be turned into actual advantage by celerity of movement.” Signal examples of this saying are afforded by the two famous passages across the Alps — that of Hannibal, which laid Italy at his mercy, and that of Napoleon two thousand years later, which resulted in the great victory of Marengo.] 4. Thus, to take a long and circuitous route, after enticing the enemy out of the way, and though starting after him, to contrive to reach the goal before him, shows knowledge of the artifice of DEVIATION.

Now the reason the enlightened prince and the wise general conquer the enemy whenever they move and their achievements surpass those of ordinary men is foreknowledge.