Two commentators, Li Ch‘üan and Chang Yü, take 形之 in the sense of 示之 “put on specious appearances.” The former says: “You may either deceive the enemy by a show of weakness—striking your colours and silencing your drums; or by a show of strength—making a hollow display of camp-fires and regimental banners.” And the latter quotes [V. 19], where 形之 certainly seems to bear this sense. On the other hand, I would point to [§ 13] of this chapter, where 形 must with equal certainty be active. It is hard to choose between the two interpretations, but the context here agrees better, I think, with the one that I have adopted. Another difficulty arises over 死生之地, which most of the commentators, thinking no doubt of the 死地 in [XI. § 1], refer to the actual ground on which the enemy is encamped. The notes of Chia Lin and Mei Yao-ch‘ên, however, seem to favour my view. The same phrase has a somewhat different meaning in [I. § 2].
24. 角之而知有餘不足之處
Carefully compare the opposing army with your own,
Tu Yu is right, I think, in attributing this force to 角; Ts‘ao Kung defines it simply as 量. Capt. Calthrop surpasses himself with the staggering translation “Flap the wings”! Can the Latin cornu (in its figurative sense) have been at the back of his mind?
so that you may know where strength is superabundant and where it is deficient.
Cf. [IV. § 6].
25. 故形兵之極至於無形無形則深閒不能窺知者不能謀
In making tactical dispositions, the highest pitch you can attain is to conceal them;
The piquancy of the paradox evaporates in translation. 無形 is perhaps not so much actual invisibility (see supra, [§ 9]) as “showing no sign” of what you mean to do, of the plans that are formed in your brain.
conceal your dispositions, and you will be safe from the prying of the subtlest spies, from the machinations of the wisest brains.