[Literally, "releases the spring" (see V. § 15), that is, takes some decisive step which makes it impossible for the army to return—like Hsiang Yu, who sunk his ships after crossing a river. Ch’en Hao, followed by Chia Lin, understands the words less well as "puts forth every artifice at his command."]
- He burns his boats and breaks his cooking-pots; like a shepherd driving a flock of sheep, he drives his men this way and that, and none knows whither he is going.
[Tu Mu says: "The army is only cognizant of orders to advance or retreat; it is ignorant of the ulterior ends of attacking and conquering."]
- To muster his host and bring it into danger:—this may be termed the business of the general.
[Sun Tzŭ means that after mobilization there should be no delay in aiming a blow at the enemy’s heart. Note how he returns again and again to this point. Among the warring states of ancient China, desertion was no doubt a much more present fear and serious evil than it is in the armies of today.]
- The different measures suited to the nine varieties of ground;
[Chang Yu says: "One must not be hide-bound in interpreting the rules for the nine varieties of ground."]
the expediency of aggressive or defensive tactics; and the fundamental laws of human nature: these are things that must most certainly be studied.
- When invading hostile territory, the general principle is, that penetrating deeply brings cohesion; penetrating but a short way means dispersion.
[Cf. supra, § 20.]