《孙子遗说》

Preface to the Residual Discourses on the Ten Commentaries to the Sunzi

A truly complete body of method yields ever more principle the more deeply it is explored; words that are truly well put seem ever more without end the more they are questioned. Only when method and speech reach so profound and inexhaustible a state are they fit to instruct the present age and to be handed down to later generations.

Confucian scholars have long felt that although the Classic of Changes (Yijing) is simple, the principles it sets forth are profound and without limit. Students of the art of war are likewise often troubled that the discussions in Sunzi’s Art of War are subtle, mysterious, and hard to exhaust. Is the Sunzi to the military schools what the Classic of Changes is to the Confucians?

The Classic of Changes embraces the three powers of Heaven, Earth, and humanity and encompasses the myriad things, taking as its mystery the transformations of Yin-Yang, which cannot be fathomed. Thus the humane, reading it, perceive the principle of humaneness; the wise perceive wisdom; and ordinary people make use of it every day without necessarily understanding its principle. The methods of Sunzi’s Art of War embrace every kind of military art and gather the teachings of the various schools, taking the mutual conversion of the unorthodox and the orthodox as the way of change. Thus those skilled in planning see stratagems in it; the deft see timely adaptation; and the three armies act according to it without necessarily grasping its mysteries to the full.

Later, scholars of the various schools interpreted the Classic of Changes one after another, and people were thereby better able to appreciate its meaning; yet this is like the mystery of the sun, moon, and stars: one can only calculate and observe the courses they display, and cannot inquire into why they are so mysterious. After the ten commentators—the ten scholars who annotated Sunzi’s Art of War—appeared, people were likewise better able to understand the methods of the thirteen chapters of the Sunzi; yet this is like the variations of the five musical tones and the five colors: the commentators can only set forth in detail what the ear can hear and the eye can see, and still cannot fully explain the subtlety of the transformations. One therefore cannot hold that the deep meaning of the Sunzi has already been exhausted by the ten commentaries.

Even so, students of the art of war who do not read the commentaries of the ten schools will find it hard to glimpse the entrance to the Sunzi. Following the tributaries in search of the source, and walking the side paths in order to enter the gate—for understanding the methods of the Sunzi, the ten commentaries are indeed of real help.

Of late, in my leisure, I have reflected on the subtle intent of the Sunzi and singled out places the ten commentaries fail to explain, some several dozen items in all. Casting the corresponding answers in the form of questions put by another person, I have written them down and named the work Residual Discourses on the Ten Commentaries. When readers see that the Sunzi still contains matter the commentators have not said to the end, they may come to believe that methods profound and without limit, and words that inquiry cannot exhaust, are indeed of a kind with the unfathomable mystery of the Classic of Changes.

Written by Zheng Youxian of Xingyang.

Someone asked, “Why, when one comes to speak of the battlefield where life and death are at stake, must one first discuss the way of the state’s survival or destruction?”

The reply was: “Sun Wu held that the use of troops is a matter of the greatest consequence, and that the crux lies in whether the right person has been chosen as general. If the general is capable, the army can win and preserve life; when the army abroad can be preserved, the state at home can endure. If the general lacks ability, the army will be defeated and suffer casualties; when the army abroad is destroyed, the state at home will perish as well. It is thus clear that the life and death of the army in the field bears upon the survival or destruction of the state at home. For this reason, after its defeat at Changping the state of Zhao moved toward ruin, and after the Sui army’s defeat on the Liao River the Sui dynasty likewise collapsed. Jiang Taigong said: ‘One who lacks far-sighted strategy, yet flaunts strength and valor and lightly opens hostilities, causing the army to be routed and the troops to scatter and endangering the very foundation of the state—such a man the ruler must never appoint as general.’ This is why one speaks first of the employment of generals and only afterward of life and death on the battlefield. Hence it is said that the general who understands the use of troops holds the people’s fate in his charge and is the arbiter of the state’s safety or peril.”

Someone asked, “The text speaks of ‘many calculations’ and ‘few calculations,’ and also of ‘no calculations.’ What do many, few, and none mean respectively?”

The reply was: “The wording of the Sunzi is by no means without foundation. It weighs war by five factors and compares one’s own side with the enemy by seven standards, and the prospects of victory on either side can all be examined from these. Among the five factors, superiority in three or four counts as many, and superiority in one or two counts as few; among the seven standards, superiority in four or five counts as many, and superiority in two or three counts as few. If one holds the advantage in both the five factors and the seven standards, one may be confident of complete victory; if one holds the advantage in not a single respect, there is no chance of victory. What is called ‘groping in darkness yet ranking the matter first’ means being wholly ignorant of the situation and yet still treating combat as the foremost concern; what is called ‘fighting first and seeking victory afterward’ means rashly opening hostilities and only then hoping to win; what is called ‘scheming for a speculative, all-or-nothing gain’ means calculating on staking everything in a single throw and profiting by luck; what is called ‘sending forth an army of reckless battle’ means dispatching troops to fight a rash and overreaching engagement.”