This is Ts‘ao Kung’s interpretation. Chang Yü adopts it, saying: 當疾進其後使首尾俱至 “We must quickly bring up our rear, so that head and tail may both reach the goal.” That is, they must not be allowed to straggle up a long way apart. Mei Yao-ch‘ên offers another equally plausible explanation: 敵未至其地我若在後則當疾趨以爭之 “Supposing the enemy has not yet reached the coveted position, and we are behind him, we should advance with all speed in order to dispute its possession.” 其 would thus denote the enemy, 後 being the preposition, and 趨 would retain its usual intransitive sense. Cf. VII. § 4: 後人發先人至. Ch‘ên Hao, on the other hand, assuming that the enemy has had time to select his own ground, quotes VI. § 1, where Sun Tzŭ warns us against coming exhausted to the attack. His own idea of the situation is rather vaguely expressed: 若地利在前先 分精銳以據之彼若恃衆來爭我以大衆趨其後無不尅者 “If there is a favourable position lying in front of you, detach a picked body of troops to occupy it; then if the enemy, relying on their numbers, come up to make a fight for it, _you may fall quickly on their rear_ with your main body, and victory will be assured.” It was thus, he adds, that Chao Shê beat the army of Ch‘in. [See p. 57.] Li Ch‘üan would read 多 for 趨, it is not easy to see why. 48. 交地吾將謹其守衢地吾將固其結 On open ground, I would keep a vigilant eye on my defences. As Wang Hsi says, 懼襲我也 “fearing a surprise attack.” The _T‘ung Tien_ reads here 固其結 (see next sentence). On ground of intersecting highways, I would consolidate my alliances. The _T‘ung Tien_ reads 謹其市, which Tu Yu explains as “watching the market towns,” 變事之端 “the hotbeds of revolution.” Capt. Calthrop translates 固其結 by the same words as 合交 in § 12: “cultivate intercourse.” 49. 重地吾將繼其食圮地吾將進其塗 On serious ground, I would try to ensure a continuous stream of supplies. The commentators take this as referring to forage and plunder, not, as one might expect, to an unbroken communication with a home base. One text, indeed, gives the reading 掠其食. Cf. § 13. Capt. Calthrop’s “be careful of supplies” fails to render the force of 繼. On difficult ground, I would keep pushing on along the road. Capt. Calthrop’s “do not linger” cannot be called a translation, but only a paraphrase of the paraphrase offered by Ts‘ao Kung: 疾過去也 “Pass away from it in all haste.” 50. 圍地吾將塞其闕死地吾將示之以不活 On hemmed-in ground, I would block any way of retreat.