s CHENG, making lateral diversion
is CH`I. Chia Lin: "In presence of the enemy, your troops
should be arrayed in normal fashion, but in order to secure
victory abnormal maneuvers must be employed." Mei Yao-ch`en:
"CH`I is active, CHENG is passive; passivity means waiting for an
opportunity, activity beings the victory itself." Ho Shih: "We
must cause the enemy to regard our straightforward attack as one
that is secretly designed, and vice versa; thus CHENG may also be
CH`I, and CH`I may also be CHENG." He instances the famous
exploit of Han Hsin, who when marching ostensibly against Lin-
chin (now 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. 3.] Here, we are told, the march
on Lin-chin was CHENG, and the surprise maneuver was CH`I."
Chang Yu gives the following summary of opinions on the words:
"Military writers do not agree with regard to the meaning of CH`I
and CHENG. Wei Liao Tzu [4th cent. B.C.] says: 'Direct warfare
favors 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
maneuver.' Li Wei-kung [6th and 7th cent. A.D.] says: 'In war,
to march straight ahead is CHENG; turning movements, on the other
hand, are CH`I.' These writers simply regard CHENG as CHENG, 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, ss. 11]. A comment on the T`ang Emperor T`ai
Tsung goes to the root of the matter: 'A CH`I maneuver may be
CHENG, if we make the enemy look upon it as CHENG; then our real
attack will be CH`I, and vice versa. 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 CHENG, on which the enemy has had his attention
fixed; whereas that is CH`I," which takes him by surprise or
comes from an unexpected quarter. If the enemy perceives a
movement which is meant to be CH`I," it immediately becomes
CHENG."]

4. That the impact of your army may be like a grindstone
dashed against an egg - this is effected by the science of weak
points and strong.
5. In all fighting, the direct method may be used for
joining battle, but indirect methods will be needed in ord