孙子曰：凡治众如治寡，分数是也﹔斗众如斗寡，形名是也﹔三军之
众，可使必受敌而无败，奇正是也﹔兵之所加，如以碫投卵者，虚实
是也。
凡战者，以正合，以奇胜。故善出奇者，无穷如天地，不竭如江河。
终而复始，日月是也。死而复生，四时是也。声不过五，五声之变，
不可胜听也。色不过五，五色之变，不可胜观也。味不过五，五味之
变，不可胜尝也。战势不过奇正，奇正之变，不可胜穷之也。奇正相
生，如环之无端，孰能穷之？
激水之疾，至于漂石者，势也﹔鸷鸟之疾，至于毁折者，节也。是故
善战者，其势险，其节短。势如张弩，节如发机。
纷纷纭纭，斗乱而不可乱也。浑浑沌沌，形圆而不可败也。
乱生于治，怯生于勇，弱生于强。治乱，数也﹔勇怯，势也﹔强弱，
形也。
故善动敌者，形之，敌必从之﹔予之，敌必取之。以利动之，以卒动
之。
故善战者，求之于势，不责于人，故能择人而任势。任势者，其战人
也，如转木石。木石之性，安则静，危则动，方则止，圆则行。故善
战人之势，如转圆石于千仞之山者，势也。
Chapter 5 :
Posture of Army Generally, management of a large force is the same as management of a few men. It is a matter of organization. And to direct a large force is the same as to direct a few men. This is a matter of formations and signals. That the army is certain to sustain the enemy's attack without suffering defeat is due to operations of the extraordinary and the normal forces. Troops thrown against the enemy as a grindstone against eggs is an example of a solid acting upon a void. Generally, in battle, use the normal force to engage and use the extraordinary forces to win. Now, the resources of those skilled in the use of extraordinary forces are as infinite as the heavens and earth, as inexhaustible as the flow of the great rivers, for they end and recommence - cyclical, as are the movements of the sun and moon. They die away and are reborn - recurrent, as are the passing seasons. The musical notes are the passing seasons. The musical notes are only five in number, but their combinations are so infinite that one cannot visualize them all. The flavors are only five in number, but their blends are so various that one cannot taste them all. In battle, there are only the normal and extraordinary forces, but their combinations are limitless; none can comprehend them all. For these two forces are mutually reproductive. It is like moving in an endless circle. Who can exhaust the possibility of their combination? When torrential water tosses boulders, it is because of its momentum; when the strike of a hawk breaks the body of its prey, it is because of timing. Thus, the momentum of one skilled in war is overwhelming, and his attack precisely timed. His potential is that of a fully drawn crossbow; his timing, that of the release of the trigger. In tumult and uproar, the battle seems chaotic, but there must be no disorder in one's own troops. The battlefield may seem in confusion and chaos, but one's array must be in good order. That will be proof against defeat. Apparent confusion is a product of good order; apparent cowardice, of courage; apparent weakness, of strength. Order of disorder depends on organization and direction; courage or cowardice on circumstances; strength or weakness on tactical dispositions. Thus, one who is skilled at making the enemy move does so by creating a situation, according to which the enemy will act. He entices the enemy with something he is certain to want. He keeps the enemy on the move by holding out bait and then attacks him with picked troops. Therefore, a skilled commander seeks victory from the situation and does not demand it of his subordinates. He selects suitable men and exploits the situation. He who utilizes the situation uses his men in fighting as one rolls logs or stones. Now, the nature of logs and stones is that on stable ground they are static; on a slope, they move. If square, they stop; if round, they roll. Thus, the energy of troops skillfully commanded in battle may be compared to the momentum of round boulders which roll down from a mountain thousands of feet in height.
