To ensure that your whole host may withstand the brunt of the enemy’s
attack and remain unshaken—this is effected by manœuvres direct and
indirect.
For 必, there is another reading 畢, “all together,” adopted by
Wang Hsi and Chang Yü. We now come to one of the most interesting
parts of Sun Tzŭ’s treatise, the discussion of the 正 and the 奇.
As it is by no means easy to grasp the full significance of these
two terms, or to render them at all consistently by good English
equivalents, it may be as well to tabulate some of the
commentators’ remarks on the subject before proceeding further. Li
Ch‘üan: 當敵爲正傍出爲奇 “Facing the enemy is _chêng_, making
lateral diversions is _ch‘i_.” Chia Lin: 當敵以正陳取勝以奇兵 “In
presence of the enemy, your troops should be arrayed in normal
fashion, but in order to secure victory abnormal manœuvres must be
employed.” Mei Yao-ch‘ên: 動爲奇靜爲正靜以待之動以勝之 “_Ch‘i_ is
active, _chêng_ is passive; passivity means waiting for an
opportunity, activity brings the victory itself.” Ho Shih:
我之正使敵視之爲奇我之奇使敵視之爲正正亦爲奇奇亦爲正 “We must cause the
enemy to regard our straightforward attack as one that is secretly
designed, and _vice versâ_; thus _chêng_ may also be _ch‘i_, and
_ch‘i_ may also be _chêng_.” He instances the famous exploit of
Han Hsin, who when marching ostensibly against 臨晉 Lin-chin (now
朝邑 Chao-i in Shensi), suddenly threw a large force across the
Yellow River in wooden tubs, utterly disconcerting his opponent.
[_Ch‘ien Han Shu_, ch. 34.] Here, we are told, the march on
Lin-chin was 正, and the surprise manœuvre was 奇. Chang Yü gives
the following summary of opinions on the words: “Military writers
do not all agree with regard to the meaning of _ch‘i_ and _chêng_.
尉繚子 Wei Liao Tzŭ [4th cent. B.C.] says: 正兵貴先奇兵貴後 ‘Direct
warfare favours frontal attacks, indirect warfare attacks from the
rear.’ Ts‘ao Kung says: ‘Going straight out to join battle is a
direct operation; appearing on the enemy’s rear is an indirect
manœuvre.’ 李衛公 Li Wei-kung [6th and 7th cent. A.D.] says: ‘In
war, to march straight ahead is _chêng_; turning movements, on the
other hand, are _ch‘i_.’ These writers simply regard _chêng_ as
_chêng_, and _ch‘i_ as _ch‘i_; they do not note that the two are
mutually interchangeable and run into each other like the two
sides of a circle [see _infra_, § 11]. A comment of the T‘ang
Emperor T‘ai Tsung goes to the root of the matter: ‘A _ch‘i_
manœuvre may be _chêng_, if we make the enemy look upon it as
_chêng_; then our real attack will be _ch‘i_, and _vice versâ_.
The whole secret lies in confusing the enemy, so that he cannot
fathom our real intent.’” To put it perhaps a little more clearly:
any attack or other operation is 正, on which the enemy has had his
attention fixed; whereas that is 奇, which takes him by surprise or
comes from an unexpected quarter. If the enemy perceives a
movement which is meant to be 奇, it immediately becomes 正.