九地篇 NO.5：
将军之事，静以幽，正以治。
能愚士卒之耳目，使之无知；
易其事，革其谋，使人无识；
易其居，迂其途，使民不得虑。
帅与之期，如登高而去其梯；
帅与之深入诸侯之地，而发其机。
焚舟破釜，若驱群羊，驱而往，驱而来，莫知所之。
聚三军之众，投之于险，此谓将军之事也。
九地之变，屈伸之利，人情之理，不可不察也。
这句啥意思：
主持军事行动，要做到考虑谋略沉着冷静而幽深莫测，管理部队公正严明而有条不紊。
要能蒙蔽士卒的视听，使他们对于军事行动毫无所知；
变更作战部署，改变原定计划，使人无法识破真相；
不时变换驻地，故意迂回前进，使人无从推测意图。
将帅向军队赋予作战任务，要象使其登高而抽去梯子一样。
将帅率领士卒深入诸侯国土，要象弩机发出的箭一样一往无前。
对待士卒要能如驱赶羊群一样，赶过去又赶过来，使他们不知道要到哪里去。
集结全军，把他们置于险境，这就是统帅军队的要点。
九种地形的应变处置，攻防进退的利害得失，全军上下的心理状态，这些都是作为将帅不能不认真研究和周密考察。
英文这么说：
It is the business of a general to be quiet and thus ensure secrecy; upright and just, and thus maintain order.
He must be able to mystify his officers and men by false reports and appearances, and thus keep them in total ignorance.
By altering his arrangements and changing his plans, he keeps the enemy without definite knowledge.
By shifting his camp and taking circuitous routes,he prevents the enemy from anticipating his purpose.
At the critical moment, the leader of an army acts like one who has climbed up a height and then kicks away the ladder behind him.
He carries his men deep into hostile territory before he shows his hand.
He burns his boats and breaks his cooking-pots;like a shepherd driving a flock of sheep,
he drives his men this way and that, and nothing knows whether he is going.
To muster his host and bring it into danger:--this may be termed the business of the general.
The different measures suited to the nine varieties of ground; the expediency of aggressive or defensive tactics;
and the fundamental laws of human nature:these are things that must most certainly be studied.
单句理解：
孙子在这里提出的其实是一种“愚兵”思想。军人的天职是服从，因此他们应当知道的是“做什么”而不是“为什么”。既然如此，将帅的军事计划就没有必要让士卒们知道。只有这样，将帅才能根据战争的实际需要随机地改变军事目标和作战计划，而且能够使这些计划得以顺利执行。
