虛實篇 NO.6：

故策之而知得失之計，作之而知動靜之理，形之而知死生之地，角之而知有余不足之處。

故形兵之極，至于無形。

無形，則深間不能窺，智者不能謀。

因形而措勝于眾，眾不能知。

人皆知我所以勝之形，而莫知吾所以制勝之形。

故其戰勝不復，而應形于無窮。

這句啥意思：

通過仔細分析可以判斷敵人作戰計劃的優劣得失；通過挑動敵人，可以了解敵方的活動規律；通過“示形”，可以弄清地形是否對敵有利；通過試探性進攻，可以探明敵方兵力布置的強弱多寡。

所以，示形誘敵的方法運用得極其巧妙時，一點破綻也沒有。

到這種境地，即使隱藏再深的間諜也不能探明我的虛實，智慧高超的敵手也想不出對付我的辦法。

根據敵情采取制勝的策略，即使擺在眾人面前，眾人也理解不了。

人們都知道我克敵制勝的方法，卻不能知道我是怎樣運用這些方法制勝的。

所以戰勝敵人的戰略戰術每次都是不一樣的，應適應敵情靈活運用。

英文這么說：

Rouse him, and learn the principle of his activity or inactivity. Force him to reveal himself,so as to find out his vulnerable spots.

Carefully compare the opposing army with your own,so that you may know where strength is superabundant and where it is deficient.

In making tactical dispositions, the highest pitch you can attain is to conceal them; conceal your dispositions,and you will be safe from the prying of the subtlest spies,from the machinations of the wisest brains.
How victory may be produced for them out of the enemy's own tactics--that is what the multitude cannot comprehend.
All men can see the tactics whereby I conquer,but what none can see is the strategy out of which victory is evolved.
Do not repeat the tactics which have gained you one victory, but let your methods be regulated by the infinite variety of circumstances.

《用兵策略》

這幾句是講對敵的策略。作者認為知己知彼，才能百戰不殆。因此要多籌劃，要了解敵人的行動規律，了解敵人所處的地理形勢，了解敵人的長處短處。為此可以有意地激怒敵人，可以實地考查，甚至可以火力偵察。這幾句所說的用兵策略，值得借鑒。