《孙子兵法》载:“水因地而制行,兵因敌而制胜。故兵无常势,水无常形;能因敌变化而取胜者,谓之神。”意思是:用兵的规律象水流,水流动的规律是避开高处而流向低处,用兵的规律是避开敌人坚实之处而攻击其虚弱的地方。水因地势的高下而制约其流向,用兵则要依敌情而决定取胜方针。所以,用兵作 “Sun Tzu’s Art of War” contains: “The system of water is based on the ground. Soldiers are defeated by the enemy. Therefore, the soldiers are incapable of change, the water is invariable, and the enemy can be victorious. The meaning is: the law of using soldiers.” Like the flow of water, the law of water flow is to avoid the heights and flow to the lower place. The law of the use of soldiers is to avoid the weak points of the enemy and attack its weakness. Because of the height of the terrain, the water constrains its flow, and the use of troops depends on the circumstances of the enemy and decides to win. Therefore, using soldiers