23. Thus the energy developed by good fighting men is as the momentum of a round stone rolled down a mountain thousands of feet in height. So much on the subject of energy. [The chief lesson of this chapter, in Tu Mu’s opinion, is the paramount importance in war of rapid evolutions and sudden rushes. "Great results," he adds, "can thus be achieved with small forces."] [1] "Forty-one Years in India," chapter 46. Chapter VI. WEAK POINTS AND STRONG [Chang Yu attempts to explain the sequence of chapters as follows: "Chapter IV, on Tactical Dispositions, treated of the offensive and the defensive; chapter V, on Energy, dealt with direct and indirect methods. The good general acquaints himself first with the theory of attack and defence, and then turns his attention to direct and indirect methods. He studies the art of varying and combining these two methods before proceeding to the subject of weak and strong points. For the use of direct or indirect methods arises out of attack and defence, and the perception of weak and strong points depends again on the above methods. Hence the present chapter comes immediately after the chapter on Energy."] 1. Sun Tzŭ said: Whoever is first in the field and awaits the coming of the enemy, will be fresh for the fight; whoever is second in the field and has to hasten to battle, will arrive exhausted. 2. Therefore the clever combatant imposes his will on the enemy, but does not allow the enemy’s will to be imposed on him. [One mark of a great soldier is that he fight on his own terms or fights not at all. [1] ] 3. By holding out advantages to him, he can cause the enemy to approach of his own accord; or, by inflicting damage, he can make it impossible for the enemy to draw near. [In the first case, he will entice him with a bait; in the second, he will strike at some important point which the enemy will have to defend.] 4. If the enemy is taking his ease, he can harass him; [This passage may be cited as evidence against Mei Yao- Ch’en’s interpretation of I. § 23.] if well supplied with food, he can starve him out; if quietly encamped, he can force him to move. 5. Appear at points which the enemy must hasten to defend; march swiftly to places where you are not expected. 6. An army may march great distances without distress, if it marches through country where the enemy is not. [Ts’ao Kung sums up very well: "Emerge from the void [q.d. like "a bolt from the blue"], strike at vulnerable points, shun places that are defended, attack in unexpected quarters."] 7. You can be sure of succeeding in your attacks if you only attack places which are undefended. [Wang Hsi explains "undefended places" as "weak points; that is to say, where the general is lacking in capacity, or the soldiers in spirit; where the walls are not strong enough, or the precautions not strict enough; where relief comes too late, or provisions are too scanty, or the defenders are variance amongst themselves."]