Left: 故知兵者,动而不迷,举而不穷. 故曰:知己知彼,胜乃不殆﹔知天知地,胜乃可全。
Hence the experienced soldier, once in motion, is never bewildered; once he has broken camp, he is never at a loss. Hence the saying: If you know the enemy and know yourself, your victory will not stand in doubt; if you know Heaven and know Earth, you may make your victory complete.
Right: 夫兵形象水,水之形,避高而趨下:兵之形,避實而擊虛;水因地而制流,兵因敵而制勝。故兵無常勢,水無常形;能因敵變化而取勝,謂之神。
Military tactics are like unto water; for water in its natural course runs away from high places and hastens downwards. So in war, the way is to avoid what is strong and to strike at what is weak. Water shapes its course according to the nature of the ground over which it flows; the soldier works out his victory in relation to the foe whom he is facing. Therefore, just as water retains no constant shape, so in warfare there are no constant conditions. He who can modify his tactics in relation to his opponent and thereby succeed in winning, may be called a heaven-born captain.