, king of the Wu State.]

16. While heading the profit of my counsel, avail yourself
also of any helpful circumstances over and beyond the ordinary
rules.
17. According as circumstances are favorable, one should
modify one's plans.

[Sun Tzu, as a practical soldier, will have none of the
"bookish theoric." He cautions us here not to pin our faith to
abstract principles; "for," as Chang Yu puts it, "while the main
laws of strategy can be stated clearly enough for the benefit of
all and sundry, you must be guided by the actions of the enemy in
attempting to secure a favorable position in actual warfare." On
the eve of the battle of Waterloo, Lord Uxbridge, commanding the
cavalry, went to the Duke of Wellington in order to learn what
his plans and calculations were for the morrow, because, as he
explained, he might suddenly find himself Commander-in-chief and
would be unable to frame new plans in a critical moment. The
Duke listened quietly and then said: "Who will attack the first
tomorrow -- I or Bonaparte?" "Bonaparte," replied Lord Uxbridge.
"Well," continued the Duke, "Bonaparte has not given me any idea
of his projects; and as my plans will depend upon his, how can
you expect me to tell you what mine are?" [1] ]

18. All warfare is based on deception.

[The truth of this pithy and profound saying will be
admitted by every soldier. Col. Henderson tells us that
Wellington, great in so many military qualities, was especially
distinguished by "the extraordinary skill with which he concealed
his movements and deceived both friend and foe."]

19. Hence, when able to attack, we must seem unable; when
using our forces, we must seem inactive; when we are near, we
must make the enemy believe we are far away; when far away, we
must make him believe we are near.
20. Hold out baits to entice the enemy. Feign disorder,
and crush him.

[All commentators, except Chang Yu, say, "When he is in
disorder, crush him." It is more natural to suppose that Sun Tzu
is still illustrating the uses of deception in war.]

21. If he is secure at all points, be prepared for him. If
he is in superior strength, evade him.
22. If your opponent is of choleric temper, seek to
irritate him. Pretend to be weak, that he may grow arrogant.

[Wang Tzu, quoted by Tu Yu, says that the good tactician
plays with his adversary as a cat plays with a mouse, first
f