Ten Commentaries on Sunzi's Lost Teachings

Someone asked: Why is "the ground of life and death" placed before "the way of survival or ruin"?

The answer: Sun Wu believed that in military affairs, the key lies in whether the general is competent. If the general is capable, the army can win and survive. If the army survives abroad, the state can be preserved at home. If the general is incompetent, the army will be defeated and perish. If the army perishes abroad, the state will be destroyed at home. Thus, external life and death are linked to internal survival or ruin. Therefore, when the army was defeated at Changping, the state of Zhao perished; when the army lost its troops at the Liao River, the Sui dynasty collapsed. Jiang Taigong said: "If one lacks strategic foresight but acts recklessly and rashly in battle, causing the army to be routed and soldiers to scatter, thereby endangering the state, the ruler must never appoint such a person as general." This is the principle of precedence. Hence it is said: "The general who understands warfare is the arbiter of the people's life and death and the master of the state's safety or danger."

Someone asked: "One who has many calculations, one who has few calculations, and even one who has no calculations—what do 'many,' 'few,' and 'none' mean?"

The answer: Sun Wu's text is not arbitrary or baseless. Broadly speaking, planning is done through the "Five Matters" and comparison through the "Seven Calculations," and the calculations of both sides are contained herein. In planning through the "Five Matters," achieving three or four constitutes "many," achieving one or two constitutes "few"; in comparing through the "Seven Calculations," achieving four or five constitutes "many," achieving two or three constitutes "few." Achieving all of the Five Matters and Seven Calculations results in total victory; achieving none of them results in no calculations. This is what is meant by acting in obscurity, engaging battle first and seeking victory afterward, scheming for lucky gains, and deploying troops that fight recklessly.

Someone asked: Beyond the benefit of calculations, what is the "circumstantial advantage" that assists?

The answer: The transmission of military methods has its constants, and their application has its variations. Constants are the laws; variations are the circumstances. Books can fully express the words of constants, but words cannot fully express the meaning of variations. The Five Matters and Seven Calculations are the benefits of constant methods. Deceptive tactics cannot be taught in advance; they are the variations of circumstantial power. Adhering to constants to seek victory is like gluing the strings of a lute or using a book to drive a chariot. Zhao Kuo could talk about warfare on paper but could not fight in practice, precisely because he spoke lightly but understood nothing of variation. Generally, laws lie in the transmission of books, while circumstances lie in human application. Sun Wu's original intent was initially to seek employment in Wu, fearing that the King of Wu would only obtain the military text and follow its plans, then discard him. Therefore, he used these words to move him, meaning that beyond the book there is the power of exploiting advantages and controlling variations, which lies in my ability to apply it.

Someone asked: By obtaining grain from the enemy, there is no cost for long-distance transport. But weapons and equipment must be taken from one's own state—why is this?

The answer: The use of weapons and equipment cannot be lent to others, nor borrowed from others. For a person, equipment inherently lies in long-term accumulation, skilled use, and adaptation to their properties of length, shortness, weight, and suitability, as well as not conflicting with one's own hands and feet. Only then can it aid in use and harm the enemy. Our equipment is inconvenient for the enemy to use; the enemy's equipment is unfamiliar to us for its convenience. If it is not prepared within the state and made familiar to the entire army through habitual use, how can one hastily borrow another's equipment in an instant to supply one's own use? The Book of Changes says: "In the Cuai hexagram, repair weapons to guard against unexpected events." Jiang Taigong said: "If plans are not set in advance, equipment will be incomplete." These all mean that it must be taken from one's own state and cannot rely on others.

Someone asked: In warfare, "attacking plans" is the highest, because it has the advantage of easily subduing the enemy without the difficulty of bloody battle. "Attacking armies" and "attacking cities" are secondary and inferior, which is very clear. Why is the strategy of "attacking alliances" different from the subtlety of "attacking plans," yet placed after it?

The answer: One who breaks the enemy's plans achieves victory without effort; one who breaks the enemy's alliances has already expended effort before achieving victory. In the camp or at the diplomatic table, through deliberation, maneuvering, and psychological warfare, one wins over the enemy's plans whether they are yet unformed or already formed, without any expenditure, and the enemy flees or surrenders without delay—this is the meaning of "attacking plans." Sometimes sending envoys and preparing the offerings of carriages and gifts, sometimes dispatching spies and expending the resources of land, gold, and jade—Zhang Yi disrupted the Six States' vertical alliance by secretly cultivating relations for several years; Wei Liaozi broke the allied forces of the feudal lords by spending 300,000 gold. In such cases, the expenditure was already great and the enemy had not submitted, and without adding the toil of conquest, one could not achieve total victory. Therefore, it should be placed after the strategies of Yan Ying, Zhang Liang, Kou Xun, and Xun Yu.

Someone asked: Sun Wu's military text consists entirely of principles. Why does he specifically say "this is the method of attacking with strategy" and "this is the method of contending for military advantage"?

The answer: Other principles discuss the arts of warfare in general terms, but only these two chapters address specific applications, warning people not to use them lightly and describing their difficulties. If one tells others of the difficulties without providing ready-made principles to assist them, it would not suffice to be a complete military text. Generally, the method of attacking with strategy prioritizes preservation as superior and destruction as inferior. If one obtains its principles, the army will not be harmed and benefits can be preserved; if one does not, there will be the calamity of losing a third of the troops. The method of contending for military advantage treats the circuitous as direct and harm as benefit. If one obtains its principles, one can arrive later but earlier; if one does not, it leads to the capture of the three armies' commanders. Are these two easy matters in warfare? Hence it is said: "One must contend for supremacy in the world through the posture of total victory." And again: "Nothing is more difficult than contending for military advantage." These are words expressing difficulty, intending to help people overcome it, and thus must explain its principles in detail. Everything that means "subduing the enemy not by battle, capturing cities not by assault, destroying a state not by prolonged warfare" is the method of attacking with strategy. Everything that means "arriving with one-tenth of the force, knowing the circuitous-direct strategy in advance" is the method of contending for military advantage. Seeing these principles, one knows they are more difficult than other chapters.

Someone asked: If the general is capable and the ruler does not interfere, victory follows. When Emperor Taiwu of the Later Wei appointed generals to lead troops, those who followed orders all won, and those who violated instructions mostly failed. When Emperor Shenwu of Qi employed generals for expeditions, those who followed strategies all won, and those who defied directives mostly suffered defeat. Are these not cases where victory came after interference?

The answer: Understanding this, one can then grasp Sun Wu's original intent. Since it is said "if the general is capable and the ruler does not interfere, victory follows," its meaning originally is "if the general is incapable and the ruler interferes, victory follows." Among the ranks of generals, abilities are not uniform. Wisdom, stupidity, courage, timidity—they are employed according to their capacities. For those with ability, grant them the power of independent command; for those without ability, grant them fixed plans. This is also like later generations criticizing Cao Cao for having his generals act according to the New Book, not knowing that Cao Cao governed his generals by indulging or restraining them based on the size of their talents. Zhang Liao and Yue Jin were partial talents skilled in defense and combat. At the Battle of Hefei, they were sealed with a letter to regulate their application. The Xiahou brothers, with the strategy of great commanders, were given authority to act flexibly without being constrained by regulations. How could it be that they were uniformly interfered with? The Zuo Commentary says: "If the general is capable and the ruler interferes, it binds the army; if the general is incapable and the ruler gives free rein, it leads to the army's ruin." Only Cao Cao deeply understood Sun Wu's military methods, and then Emperor Taiwu and Emperor Shenwu could merely approach Cao Cao's heroic strategy. If not for Sima Yi, how could Sun Wu's profound meaning be elucidated?

Someone asked: Victory can be predicted but not compelled, because it lies with the enemy. Making the rested enemy toil, making the united enemy disperse—rest and unity lie with the enemy, yet we can make them toil and disperse—is this not something that can be compelled?

The answer says: Ancient texts state that one must observe the enemy's vulnerabilities before acting, and that such vulnerabilities must not be missed. Generally, if we observe that the enemy has no exploitable opening, we cannot force it to become the basis for our victory—this is the meaning of "cannot be created." Since the enemy does have an exploitable gap, we can employ stratagems within it and not miss the opportunity to defeat the enemy—this is the meaning of "can be known." If the enemy's ruler is wise and his ministers capable, the generals are intelligent and loyal, they do not believe the slander of petty men and thus harbor no suspicion, and they do not act for petty gain, then how can their comfort be turned into fatigue? How can their unity be turned into division? It was because of King Ping of Chu's incompetence and Nang Wa's greed that the men of Wu were able to repeatedly harass them until they were exhausted. It was because of Xiang Yu's cruelty and Fan Zeng's narrow-mindedness that Chen Ping was able to use a stratagem of sowing discord to divide them. The seeds of vulnerability lie hidden before comfort and unity; the strategies of fatigue and division arise after the vulnerabilities appear—this is what is meant by "can be known." Thus, only an enemy without vulnerabilities cannot be forcibly exploited.

Someone asks: "Defend when strength is insufficient; attack when strength is abundant"—what is its meaning?

The answer says: The one who says, "My strength for defense is insufficient; my strength for attack is abundant," is Cao Cao. The one who says, "One whose strength is insufficient may defend; one whose strength is abundant may attack," is Li Quan. The one who says, "It is not explained by strength or weakness," is Li Jing. The one who says, "The method of defense lies in showing insufficiency to the enemy; the method of attack lies in showing abundance to the enemy," is Emperor Taizong of Tang. The methods of attack and defense are not inherently about one's actual strength or weakness, nor are they about deliberately creating false appearances to deceive the enemy. Rather, they are about correctly employing the conditions of abundance and insufficiency to strengthen oneself and overcome the enemy. What is called "insufficiency" is when we conceal our traces in subtlety, so that the enemy cannot perceive them. What is called "abundance" is when we seize the momentum of strength, so that the enemy cannot withstand it. "Insufficiency" is a term for subtlety. When we defend, we erase our traces where they cannot be seen, hide our sounds where they cannot be heard, and conceal our subtlety at the point of subtle insufficiency, so that the enemy does not know where to attack. This is what is meant by "concealed in the depths of the earth." "Abundance" is a term for strength. When we attack, it is like a sudden thunderclap and startling lightning, destroying mountains and breaching dikes, creating momentum at the extreme of abundant strength, so that the enemy does not know how to defend. This is what is meant by "moving from the heights of the heavens." This is the meaning of abundance and insufficiency.

Someone asks: The mass of the three armies can be made to inevitably suffer the enemy's attack without being defeated—this is due to the orthodox and the unorthodox. Suffering attack and not being defeated are two meanings; do they have distinct emphases regarding the orthodox and the unorthodox?

The answer says: Sun Wu discusses division of forces, forms and names, the orthodox and the unorthodox, and the substantial and the insubstantial. Among these four, he alone elaborates on the orthodox and the unorthodox in detail, knowing that its principles are profound, and the emphases of the two meanings have not yet been clarified. He also says: In all battles, "engage with the orthodox force and achieve victory with the unorthodox force." Engaging with the orthodox force means that the orthodox force emphasizes suffering the enemy's attack; achieving victory with the unorthodox force means that the unorthodox force emphasizes ensuring one's own side is not defeated. Using "engage" to explain suffering attack and "victory" to explain not being defeated—is this not very clear?

Someone asks: Sun Wu discusses the mutual transformation of the orthodox and the unorthodox, with both arising from each other. Why then does he only speak of "being skilled in using the unorthodox"?

The answer says: This is a missing passage. In general, things like heaven and earth, rivers and seas, the sun and moon, the four seasons, the five colors, and the five flavors all take on the meaning of inexhaustibility, mutual generation, and mutual transformation. Thus, at the beginning he discusses using the orthodox to engage and the unorthodox to gain victory, and finally he concludes that the transformations of the orthodox and the unorthodox are inexhaustible, mutually generating each other like a cycle with no end. How could a single word "unorthodox" alone produce transformations and alternating inexhaustibility? It should say, "He who is skilled in using the orthodox and the unorthodox is as inexhaustible as heaven and earth."

Someone asks: The meaning of "the momentum is steep" is easy to understand. What is the intent behind "the rhythm is short"?

Source text: It is said: Even if the force is very strong, if it is not controlled with a short, close range and applied appropriately, it cannot harm an object. The fragile silk of Lu, even a strong crossbow's arrow at the end of its flight cannot pierce it; the light tip of a hair, even a violent wind when it has weakened cannot lift it. Although a bird of prey is swift, if it comes from a high and distant place, until it exhausts the strength of its wings, how can it strike and tear its prey? People often regard long-distance combat as difficult—this is the reason. Therefore, when Qu Yi defeated Gongsun Zan, he launched an ambush within several tens of paces. When Zhou Fang defeated Du Zeng, he rushed in from outside thirty paces. This grasps the meaning of "short rhythm."

Translation: Someone says: Even if the force is very strong, if it is not controlled with a short, close range and applied appropriately, it cannot harm an object. The fragile silk of Lu cannot be pierced by the final flight of a strong crossbow bolt; the light tip of a hair cannot be lifted by the waning force of a gale. Although a bird of prey is swift, if it descends from a high and distant place, by the time its wing strength is exhausted, how can it strike and tear its prey? This is why distant formations are considered difficult to fight. Thus, when Qu Yi defeated Gongsun Zan, he unleashed his ambush within a distance of several tens of paces. When Zhou Fang defeated Du Zeng, he charged from outside thirty paces. This embodies the principle of "short rhythm."

Source text: Someone asks: Do the methods of the thirteen chapters each originate from their chapter titles?

Translation: Someone asks: Do the methods of the thirteen chapters each originate from their chapter titles?

Source text: The answer says: Their meanings each adhere to the title of the chapter, and they never speak in a diffuse or rambling manner. Take "Substantial and Insubstantial" for example: the meaning of the entire chapter, from beginning to end, never departs from the application of the substantial and the insubstantial, though the wording differs. The main point is either the substantial or the insubstantial, not the substantial then the insubstantial, or not the insubstantial then the substantial. If it is not that I am substantial and the enemy is insubstantial, then I am insubstantial and the enemy is substantial. Otherwise, the substantial and the insubstantial lie in the relationship between the two sides, and a skilled commander transforms the substantial into the insubstantial and the insubstantial into the substantial. Although it flows and changes in ten thousand ways, its essence does not go beyond these two aspects. In general, what is meant by "the one awaiting the enemy is at ease" is that his force is substantial. "The one hastening to battle is fatigued" means his force is insubstantial. "Drawing the enemy to come" means the insubstantial lies with the enemy. "Not being drawn by the enemy" means the substantial lies with me. "Luring him with profit" means employing the enemy in his insubstantial state. "Harming him" means nurturing my substantial state. "When at ease, being able to tire him; when well-fed, being able to starve him; when settled, being able to move him" means that ease, being well-fed, and being settled are substantial, while fatigue, hunger, and being moved are insubstantial; the enemy is substantial, and I am able to make him insubstantial. "Moving through places where there is no enemy" means rushing to the enemy's insubstantial areas while supporting my substantial state. "Attacking what he does not defend" means avoiding the substantial and striking the insubstantial. "Defending what he does not attack" means placing my substantial force to guard against the insubstantial. "The enemy not knowing what to defend" means engaging the enemy's insubstantial aspect. "The enemy not knowing what to attack" means encountering my substantial aspect. "Formless and soundless" means the extreme of the substantial and insubstantial, entering into the subtle and divine. "Being irresistible" means taking advantage of the insubstantiality of the enemy's preparations. "Being unassailable in pursuit" means husbanding the substantiality of my force. "Attacking what he must rescue" means exploiting his insubstantiality, so that what is substantial becomes insubstantial. "Making him go where he does not intend" means being able to be substantial, so that what is insubstantial becomes substantial. "Revealing form to the enemy so that he divides his forces" means clearly seeing the enemy's substantial and insubstantial conditions. "Being formless so that I concentrate my forces" means revealing the subtlety of my substantial and insubstantial state. "Engaging in battle with an agreed-upon force" means the enemy's insubstantiality cannot match my substantiality. "Being few in number yet preparing against many" means not recognizing the forms of the substantial and insubstantial. "Being many in number yet preparing for oneself" means being able to calculate the conditions of the substantial and insubstantial. "Fighting a decisive battle a thousand li away" means foreseeing the substantial and insubstantial. "Left and right being unable to rescue each other" means trusting in the enemy's substantial and insubstantial conditions. "The men of Yue having no effect on victory or defeat" means the Yue general did not recognize the substantial and insubstantial conditions of Wu. "Estimating, spying, showing form, and testing" are methods for distinguishing the substantial and the insubstantial. "Gaining, moving, living, and having abundance" are substantial; "losing, being still, dying, and being insufficient" are insubstantial. "The enemy being unable to spy out my plans" means externally confusing the enemy with the changes of the substantial and insubstantial; "no one knowing the form by which I achieve victory" means internally deluding the troops with the methods of the substantial and insubstantial. "Water shapes its flow according to the ground; troops achieve victory according to the enemy" means using the high and low of water to illustrate the divine unpredictability of my substantial and insubstantial changes. "What the five elements overcome" is substantial; "what they are overcome by" is insubstantial. "What the four seasons come" is substantial; "what they go" is insubstantial. "When the sun is long" is substantial; "when it is short" is insubstantial. "When the moon is born" is substantial; "when it dies" is insubstantial. All these are categories of the substantial and insubstantial, and cannot be rigidly adhered to. By extending this reasoning, the meanings of the remaining twelve chapters all follow this pattern, except that commentators have not been able to elaborate on them in detail.

Answer: The principles of each chapter all revolve around the meaning of the chapter title, never straying into random or generic discussion. For example, in the chapter "Emptiness and Fullness," the entire chapter's principles, from beginning to end in sequence, never depart from the application of emptiness and fullness; only the wording differs. Its intended focus is either not fullness but emptiness, or not emptiness but fullness. Either I am full and the enemy is empty, or I am empty and the enemy is full; otherwise, emptiness and fullness exist between both sides, and those skilled in warfare can turn fullness into emptiness and emptiness into fullness. Although it flows through myriad changes, its essential points do not go beyond these two aspects. Everything called waiting for the enemy means being at ease, which is strength in fullness; rushing about in battle means being fatigued, which is strength in emptiness. Being able to move the enemy is having emptiness on the enemy's side; not being moved by the enemy is having fullness on our side. Using profit to lure the enemy is making the enemy rush into empty places; using harm to threaten the enemy is nurturing our own fullness. Making the weary enemy labor, the well-fed enemy hungry, the stable enemy shaken: ease, satiety, and stability are fullness; fatigue, hunger, and instability are emptiness. This is where the enemy is full yet we can make them empty. Marching through unoccupied territory is heading toward the enemy's emptiness while increasing our own fullness. Attacking where the enemy does not defend is avoiding fullness and striking emptiness. Defending where the enemy does not attack is deploying fullness to guard against emptiness. When the enemy does not know how to defend, it is striking the enemy's empty points; when the enemy does not know how to attack, it is encountering our full points. Having no form and no sound is the ultimate of emptiness and fullness, entering the realm of subtlety and mystery. Being irresistible is taking advantage of the enemy's unprepared emptiness; being unpursuable is conserving our own strength in fullness. Attacking where the enemy is sure to rescue is exploiting emptiness, so fullness turns into emptiness. Drawing the enemy elsewhere is preserving fullness, so emptiness turns into fullness. Revealing the enemy's form and causing their forces to scatter is seeing the details of the enemy's emptiness and fullness; concealing our form and concentrating our forces is showing the marvel of our own changes between emptiness and fullness. Agreeing to engage the enemy in battle means the enemy's emptiness cannot withstand our fullness. Having few troops yet preparing against the enemy means not understanding the pattern of emptiness and fullness; having many troops yet preparing ourselves means being able to predict the situation of emptiness and fullness. Meeting in battle a thousand li away means foreseeing emptiness and fullness in advance; left and right unable to rescue each other means trusting the enemy's emptiness and fullness. The people of Yue providing no help in victory or defeat is because the Yue general did not understand Wu's emptiness and fullness. Planning, scouting, showing forms, and comparing are methods to discern emptiness and fullness. Gaining, moving, living, and having surplus are fullness; losing, stopping, dying, and being insufficient are emptiness. When the enemy cannot spy out our plans, it is using changes of emptiness and fullness to confuse the enemy externally; when the enemy does not know our winning formations, it is using methods of emptiness and fullness to fool our own soldiers internally. Water is constrained by the terrain to control its flow, and using troops is constrained by the enemy to control victory; this uses the height or lowness of water to analogize the unfathomable marvel of our own changes in emptiness and fullness. The five elements overcoming each other is fullness; being overcome is emptiness. The four seasons arriving is fullness; departing is emptiness. The daylight lengthening is fullness; shortening is emptiness. The moon appearing is fullness; disappearing is emptiness. These are all categories of emptiness and fullness and should not be rigidly adhered to. By this analogy, the principles of the remaining twelve chapters all follow this pattern; only the commentators cannot explain them in detail.

Original text:

Someone asked: "Military contest is for profit; mass contest is for danger." Army and mass, profit and danger—do the meanings truly differ?

Answer: Sun Wu's words were never uttered without meaning. "Military contest is for profit" refers to the method of military contest mentioned below. Only by contesting and obtaining this method of military contest can one then gain the profit of defeating the enemy. "Mass contest is for danger" refers to the whole army contesting for profit mentioned below. Only by fully committing the entire three-army mass to contest does one fail to reach profit and instead suffer danger. Because military contest is contesting according to method; mass contest is the whole army rushing. What is called profit means setting out later but arriving first; what is called danger means the commander-in-chief being captured.

Original text:

Someone asked: "War is established by deception, moved by profit, and changed by division and concentration." Establishment, movement, and change—are these three used in sequence?

Answer: The way of the ancient kings and the school of military strategists each have a sequence of root and branch, first and last, in what they use, but what they value differs. The way of the ancient kings values benevolence and righteousness, supplemented by expediency. The school of military strategists prizes deception and profit, ending with change. The Sima Method takes benevolence as the root; Sun Wu establishes by deception. The Sima Method governs with righteousness; Sun Wu moves by profit. The Sima Method, when the correct path fails to achieve its intent, uses expediency; Sun Wu uses division and concentration as change. Because one rooted in benevolence will certainly govern with righteousness; one who establishes by deception will certainly move for profit. What the sage calls expediency, the military strategist calls change. Without root and establishment, there is no way to cultivate oneself; without governance and movement, there is no way to adapt to the times; without expediency and change, there is no way to defeat the enemy. Only after having root and establishment can one govern and move; only after being able to govern and move can one then use expediency and change. Expediency and change are meant to aid governance and movement; governance and movement are meant to support root and establishment. This order of root and branch, first and last, is roughly similar.

Original text:

Someone asked: All of Sun Wu's discussions on raising armies and moving masses are methods; why does he alone call this "the method of using the masses"?

Answer: In Sun Wu's method, the extraordinary and the orthodox value mutual generation; control and expediency are used together without end. Since he uses orthodox troops for control to govern his own army, he never fails to use extraordinary troops with expediency to defeat the enemy. In his discussion of strategic advantage, placing numbers and forms first is the control for governing oneself. Placing the extraordinary and orthodox, emptiness and fullness later is the expediency for defeating the enemy. This is control first, then expediency. Everything called "standing in an invincible position without losing the chance to defeat the enemy," "cultivating the Way and preserving the laws," "preserving oneself and then achieving complete victory," are all techniques of mutual generation and dual use, first and last. Drums, bells, and flags are used to unify the people's ears and eyes. Once the people are unified, the brave cannot advance alone, nor the cowardly retreat alone—what method is this? It is the correct method of control for governing oneself. It only suffices to use our three armies. This method never extends to the extraordinary arts of defeating others. Those who discuss military matters often stop here. But Sun Wu does not. He says: This is the method of using our masses. Everything called "changing the enemy's ears and eyes" and "seizing the enemy's heart and spirit" is the extraordinary method of using stratagems to defeat the enemy.

The reply: Sun Wu's principles hold that the interplay of orthodox and unorthodox tactics lies in their mutual generation; restraint and expediency are used together without end. He employs orthodox methods to restrain and govern his own army, yet he never fails to use unorthodox tactics for expediency to defeat the enemy. When discussing strategic advantage, he places division of forces and forms and signals first—this is self-governance through restraint. He places orthodox and unorthodox, emptiness and fullness later—this is defeating the enemy through expediency. This is to prioritize restraint and then expediency. All that is called standing invincible without losing the opportunity to defeat the enemy, cultivating governance and preserving laws, first preserving oneself and then achieving complete victory—these are practices of mutual generation and sequential application with method. Because drums, bells, and banners are used to unify the soldiers' ears and eyes. Since the soldiers are unified, the brave cannot advance alone, nor the cowardly retreat alone. What principle is this? It is the orthodox method of restraint and self-governance. It can only be used to command the masses of my three armies. This principle originally does not address the unorthodox strategies for defeating the enemy. Those who discuss military tactics often stop here. Sun Wu is not like this. He says: This is the principle for commanding my troops. All that is called altering the enemy's ears and eyes and seizing the enemy's spirit is the unorthodox method of winning through expediency.

Someone asks: When seizing spirit, it must be said of the three armies; when seizing mind, it must be said of the general. Why is this?

The reply: The three armies are primarily concerned with combat; the general is primarily concerned with strategy. Combat relies on spirit; strategy operates with the mind. Rousing to battle, regardless of ten thousand deaths, is driven by spirit. Deep thought and long-range planning to respond to myriad changes are governed by the mind. If spirit is seized, they become timid in combat; if mind is seized, they become confused in strategy. The lower ranks cannot fight; the higher ranks cannot plan. When the enemy's upper and lower ranks are timid and confused, then our army can seize the opportunity in one strike to defeat them. The Zuo Zhuan says: "At the first drum, spirit is roused; at the second, it declines; at the third, it is exhausted." This is seizing the spirit of combat. To take the initiative and seize the opponent's mind is to seize the mind of strategy. The matters of the three armies and the general are different.

Someone asks: From the Calculations chapter to the Employment of Spies chapter, the principles in each are all essential and profound. Why is this alone said to be the subtlety of the art of war?

The reply: When matters reach a point of doubt, only then does one recognize the clarity of the undoubting. When opportunities become difficult to decide, only then does one recognize the wisdom of the decisive. In the art of war, principles arise from what the masses cannot determine with certainty, yet my clear wisdom sees through without hesitation. Thus, what I gain naturally surpasses the masses, and I penetrate the ultimate subtlety of the principles. As for saying "do not attack a high hill" and "do not oppose a slope with your back," there are indeed opportunities when one can attack or oppose. "Do not pursue feigned retreats" and "do not attack elite troops," there are indeed benefits when one can pursue or attack. "Do not eat bait troops" and "do not intercept returning troops," there are indeed reasons when one can eat or intercept. "When besieging an army, leave an opening" and "do not pursue a desperate foe," there are indeed victories when one does not leave an opening or can pursue. These fall outside the constant principles of military strategists and involve subtle techniques of repetition and variation. The wise man does not doubt and can decide—this is what is called the subtlety of the art of war.

Someone asks: In the Nine Variations chapter, what are the five matters that are set forth?

The reply: Someone says: The so-called "nine variations" refer to the adaptations for the nine types of terrain. Scattered ground, light ground, contested ground, intersecting ground, thoroughfare ground, heavy ground, sunken ground, encircled ground, and death ground—these are the names of the nine types of terrain. Unifying will, keeping troops tightly connected, urging from behind, cautious defense, strengthening alliances, continuous supply of provisions, speeding up the route, blocking gaps, and displaying determination to die—these are the methods of adaptation for the nine types of terrain. Speaking of nine variations yet only mentioning five is due to omissions and disordered sequence. The text below says: "If the general is able to understand the advantages of the nine variations of terrain, then he knows how to employ troops. If the general cannot understand the advantages of the nine variations, even if he knows the terrain, he cannot gain its advantages." This makes it very clear that the nine variations refer to the nine types of terrain. Therefore, it is deliberately stated in the Nine Terrains chapter: "The adaptations for the nine types of terrain, the principles of human feelings, cannot be examined carelessly." Since this is so, why is there the text of the nine variations? The reply: Sun Wu's statement "the general does not understand the advantages of the nine variations" and also says "governing troops without knowing the techniques of the nine variations" is because the nine terrains are used to explain the advantages of adaptation, so it says that not knowing adaptation means not gaining the advantages of terrain. The nine variations are used to discuss the application of techniques, so it says that not knowing techniques means not gaining the function of men. Therefore, the six terrains have physical terrain, and the nine terrains have names; the nine names each have adaptations, and the nine adaptations each have techniques. Knowing the terrain but not the names leads to blind decision-making; knowing the names but not the adaptations leads to blind combat in deploying troops; knowing the adaptations but not the techniques leads to failure in application. This is why the six terrains, nine terrains, and nine variations all discuss the advantages of terrain but are divided into separate chapters. Li Quan's combining "roads that are not taken" and the five advantages below into ten variations is erroneous. He also identifies the text below as the five advantages—where is the meaning of five advantages? "Do not linger on death ground" should be "light ground," because "light" implies not lingering.

Someone asks: All encampments favor high ground and dislike low ground. Taigong says: "If the three armies encamp on a high mountain, they will be besieged by the enemy." Does this mean they favor high ground?

The answer: Sun Wu's "high" is not the same as the Grand Duke's "high." The Grand Duke discusses the most perilous places in the world. High mountains and huge rocks, towering above, without grass or trees, exposed to attack from all sides. Because there are no grass or trees, there is a lack of benefits for grazing and gathering firewood; exposed to attack from all sides, it cuts off the routes for entry and exit and transport. One can ascend but cannot descend, one can die but cannot linger long. This certainly has the harm of being besieged. What Sun Wu discusses is the situation of taking advantage of favorable terrain. Encamping in elevated and hilly places, causing the enemy to come and engage in battle, they will suffer the harm of climbing heights, facing hills, and going against slopes, while our side can rely on the high ground, take advantage of the downward momentum, like pouring water from a height, rolling down a round ball, tumbling rocks, or releasing accumulated water. Additionally, nourishing troops in a place of life, occupying solid ground, first facilitating the supply route, in battle there is the advantage of momentum, in defense there is the stability of occupying solid ground. Encamping brings the benefit of nourishing troops and sufficient food, departing brings the advantage of convenient roads leading to a path of life. Even if there are a million enemy troops, how can they besiege our side in the high place? Emperor Taiwu Tuoba Tao besieged Yao Xing at Tian Du, and Li Xian proposed a plan to send elite troops to ambush and intercept, cutting off the supply route at Chai Bi. This was Yao Xing committing the taboo of occupying high ground, and Li Xian obtaining the method of besieging the enemy, very clear. Those who study Sun Wu must deeply understand the discourse on "favoring heights," yet not grasp the Grand Duke's discussion of extremely perilous places. Only after knowing those who understand the advantages of terrain can one discuss this book with them.

Someone asks: The six terrains are about terrain, and it also discusses the commander having six kinds of defeat—why is this?

The answer: Fearing that later generations who study military tactics might confine the principles of victory and defeat to terrain. Therefore it is said: Terrain is an aid to military tactics, not the way of the supreme commander. The Grand Duke discusses the way of the chief commander, selecting three who are skilled in using the advantages of the land and entrusting them, so terrain is originally not the general's affair. What is called estimating the enemy and deciding victory is the way of the supreme commander. One who understands this way of being a general will surely be victorious in battle. One who does not understand this way of being a general will surely be defeated in battle. All that is called "flight," "laxity," "collapse," "fall," "chaos," and "rout"—these six are the principles of defeat, the great responsibility of the commander, which cannot but be carefully examined. Therefore the principles of victory and defeat cannot be confined to terrain, but lie in the skill or clumsiness of the commander. As for the Nine Terrains, it is the same, saying that both hardness and softness obtain the principle of terrain. The general's task is to be calm and profound, correct and stern, driving the masses of the Three Armies like a flock of sheep, coming and going, not knowing where they are going—this is the general's task. Specifically giving warnings in the Six Terrains and Nine Terrains—this is the profound intention of Sun Wu.

Someone asks: "Death, how could it not be obtained? The officers and men exert their strength." Various commentators interpret this as two sentences—why is this?

The answer: Human nature, if one pursues something extremely difficult, one disregards something extremely easy; if one abandons something extremely great, one does not begrudge something extremely small. Death is harder than life. If one is willing to endure the difficulty of ten thousand deaths, then how much more is the ease of coming out alive? The body is greater than strength. If one abandons the greatness of oneself, then how much more is the smallness of exerting strength? Sun Wu's meaning is that the officers and men of the Three Armies, when cast into a place with no retreat, then even if white blades are before them, they will have something they do not avoid. If they do not avoid death, how much more life? If they do not care for themselves, how much more their strength? Therefore it is said: "Death, moreover, does not mean rout." The officers and men of the Three Armies, not fearing the difficulty of death, how can they not exert their strength to the utmost? "Death, how could it not be obtained? The officers and men exert their strength." Various commentators break this into two sentences—this is not Sun Wu's original intention.

Someone says: "Tether the horses and bury the chariot wheels." Various commentators interpret "tether" as "bind," or say it means binding the horses into a square formation—why is this?

The answer: Interpreting "tether" as "bind"—this explanation does not conform to the classics. According to "bind" and saying it as "tether" is not Sun Wu's original intention. Probably "tether" should be read as the character "release." Sun Wu's statement originally means that because the hearts of the people are scattered, even if one forcibly fixes and restrains them, it is not sufficient to rely on. The method of fixing and restraining is nothing more than limiting their movement. In ancient times, when using troops, men rode chariots into battle, and chariots were drawn by horses. Now if one wants to make men fixed and not scattered, without a policy of unified courage, even if one releases the horses to graze and buries the chariot wheels in the ground, it is not sufficient to rely on them to not scatter. Alas! The soldiers in the chariot, the shafts cannot be driven without horses, the wheels cannot race without ruts, yet they still run about scattered and not unified—then the root lies in using policy to unify their hearts.

Someone asks: The conditions of troops prioritize speed, and it also speaks of the affairs of using troops. Are the meanings of "conditions" and "affairs" indeed different?

The answer: What cannot be fathomed and is stored within the heart is conditions; what is manifested in action and accomplished externally is affairs. Conditions are hidden before affairs, and affairs appear after conditions. This is the difference between the hidden and manifest, the prior and subsequent in the method of using troops. What is called the conditions of troops prioritizing speed is because the places our side passes through and attacks must be beyond the enemy's expectations and unpreparedness. Using lightning-fast troops, appearing where the enemy cannot anticipate or prepare, originally lies in the heart being secret and not leaked, even if there are deeply scheming spies, they cannot pre-plan or spy out. What is called the affairs of using troops is because the enemy's intentions have already complied and can be judged in detail, the enemy's weaknesses have already appeared and can be seized upon. Once concentrating troops to attack the enemy, killing the enemy general a thousand li away, causing the enemy troops to have no time to form ranks and fight, the cities have no time to defend—this is because the situation of the enemy's defeat has already become evident, and our side's military momentum has already formed externally. Therefore it is said: What is called skillfully accomplishing affairs is this meaning. This is the difference between conditions and affairs, the hidden and manifest, the prior and subsequent.

Someone asks: Among the Nine Terrains, there is also "cut-off terrain"—why is this?

The answer: Raising troops and mobilizing the masses, leaving one's own state, crossing one's own territory, and just entering the enemy's region, at the border boundaries, the passes, bridges, and fords that are traversed, causing our rear forces to be behind, and writing proclamations to cut off the rear route—this is to prohibit the soldiers' feelings of looking back homeward, and to block their intentions of retreating and fleeing. The Sima Fa says: "Writing off relatives and cutting off connections, this is called cutting off thoughts and unifying considerations." The Wei Liaozi's Zhongjun Ling says: "If you encounter one who flees, kill him." This is the meaning of "cut-off terrain." However, why is it not listed among the Nine Terrains in advance? Because the methods of the Nine Terrains all have contingencies, but cut-off terrain has no contingencies. Therefore it is discussed within the Nine Terrains, but cannot be included in their number. Some interpret "crossing the border" as crossing another person's state, like Qin crossing Jin to attack Zheng—this is forced interpretation.

Someone asks: Not knowing the plans of the feudal lords cannot make alliances in advance; not knowing the terrain of mountains, forests, dangerous defiles, swamps, and marshes cannot march the army; not using guides cannot obtain the advantages of the land. This is repeatedly emphasized in the chapters "Military Contention" and "Nine Terrains"—why is this?

The answer: These three methods are all the tactics of marching, contending for advantage, emerging and disappearing, coming and going, slow and fast, advance and retreat. Because the method of military contention lies precisely in transforming the circuitous into the direct, and striking after the enemy but arriving first is urgent. The advantages of the Nine Terrains emphasize that the stakes of a guest army penetrating deep into enemy territory are great. Without these three methods, how can one act? Alas! When contending with others over the variable of the circuitous and direct, rushing into dangerous terrain, treading on the enemy's living ground, seeking unfamiliar lost paths—if one does not unite the aid of neighboring states, let them guide the army, clearly mark the terrain of mountains, rivers, forests, foothills, dangerous defiles, obstacles, swamps, and wetlands as markers, and seek local familiar people as guides—then with one move one will surely lose the way, with one action one will surely be in difficulty. What difference is this from chasing a deer without a forest warden, only entering the mountains and forests, not taking the fields, and stubbornly going against the nature of horses? Wanting to seize the victory of the circuitous and direct, seeking the advantage of deep penetration—how can one obtain convenience? Is it not profoundly meaningful to mention this repeatedly in two chapters?

Someone asks: What are "rewards without fixed rules" and "orders without established policy"?

It is said: In governing the army and commanding the masses, implementing rewards and issuing orders, there are generally established norms. Yet now, if one wishes to drive the entire three armies, making them unaware of the advantages and disadvantages, and to confuse the enemy through various means, thereby seizing control based on favorable conditions, then rewards cannot be bound by regular laws, and commands cannot be fixed by regular governance. Alas! Rewards based on regular laws are insufficient to deceive the masses; commands based on regular governance are insufficient to confuse the enemy. Thus, rewards are sometimes not bound by regularity, and commands are sometimes not fixed by regularity—this is the general’s exercise of authority. Advancing with heavy rewards, rewarding merit without fail—this is the norm for rewards. When Wu Qi reconnoitered the enemy, he rewarded those who retreated; when Ma Long recruited brave warriors, he rewarded them before battle—these were rewards without regularity. Announcing beforehand, repeatedly admonishing, giving triple orders and five warnings—this is the norm for commands. Sunzi said: It is like driving a flock of sheep back and forth, not knowing where they are going. When Li Su attacked Wu Yuanji, upon setting out, his troops asked for the destination, and he said: “Stop after advancing east for sixty li.” When they reached Zhangchai Village, the generals asked where to encamp, and he said: “Enter Caizhou.” This was a command without regular governance.

Someone asks: The use of spies and the dispatch of spies—what is the essence of sagely wisdom, benevolence, and righteousness in this?

It is answered: The use of spies refers to the methods of employing spies. Sometimes relying on circumstances, sometimes on expedient measures, not necessarily dependent on individuals. The sage is all-knowing, the wise think deeply and far ahead; without the insight of such sagely wisdom, how can one safely rely on circumstances and expedients to sow discord among the enemy? The dispatch of spies refers to sending people as spies. Between myself and the spy, there exists a situation of mutual suspicion. I suspect the spy may face the calamity of destruction, and the spy suspects I may have designs to harm him. Without benevolence and grace, one cannot win the spy’s heart; without righteousness and decisiveness, one cannot dispel one’s own doubts. When the ruler does not suspect the guest, and the guest does not distrust the ruler, then they can enter a thousand deadly places and achieve merit. The King of Qin sent Zhang Yi to serve as prime minister of Wei; for years there was no success, yet he secretly treated him generously—this was using grace to win the spy’s heart. Emperor Gaozu of Han gave Chen Ping hundreds of thousands in gold to sow discord among the lords of Chu. Chen Ping was a deserter and captive from Chu, yet he did not inquire into his comings and goings—this was using righteousness to dispel his own doubts.

Someone asks: Yi Yin and Lü Shang were sages of antiquity—did they ever serve as spies for Shang and Zhou? What Sunzi cites—does this not exalt the art of spying and value it?

It is answered: In ancient times, those who established great deeds and accomplished great achievements never failed to adhere to the straight path. When the straight path could not realize their intentions, they never failed to use expedients to fulfill righteousness. When affairs reach the point of using expedients, what then cannot be done? But if they are handled with principle and ultimately return to the straight path, then expedients do not harm the sage’s virtue. In general, what is entirely called spying by the military strategists is called expediency by the sages. If Tang of Shang had not obtained Yi Yin, he could not have fully understood the evils of Xia’s governance; if Yi Yin had not been in Xia, he could not have accomplished Tang’s good governance. If King Wu of Zhou had not obtained Lü Shang, he could not have examined the crimes of the Shang king; if Lü Shang had not been in Shang, he could not have achieved King Wu’s virtue. Without these two men, they could not have established the righteous acts of following Heaven, responding to the people, punishing the guilty, and pacifying the masses—so was this not acting as spies in Xia and Shang? Yet, because they were handled with principle and ultimately returned to the straight path, it is called expediency. What the military strategists call spying flows away and does not return to the straight path, cannot accord with righteousness, and enters the realm of deceit, so it is called spying. What is meant by using the highest wisdom to achieve great merit is precisely the expediency of Yi Yin and Lü Shang. Expediency and spying share the same substance but differ in name.

Someone asks: Why is spying placed at the end of the text?

It is answered: Among the methods of warfare, only spying is most profound, subtle, and unfathomable, and cannot be lightly discussed. The saying “Without sagely wisdom, one cannot use spies; without subtlety and skill, one cannot obtain the truth from spies” expresses the difficulty of the matter. When Sunzi first presented his thirteen chapters to the King of Wu, he also intended to use the methods in his book to teach Helü the art of war. In the initial stage of teaching, when the student is in a state of ignorance, the key lies in starting with the easy and advancing to the difficult, first clarifying the obvious and then the profound, guiding according to order from beginning to end, so that people are not confused. Therefore, he first taught the methods of measurement, calculation, and comparison, then gradually dealt with the tactics of attack and defense, dispositions, emptiness and fullness, and maneuvering for advantage, progressively reaching the preparations for marching, nine changes, terrain, place names, and fire attack. Only after all methods are understood can one discuss the profundity of the art of spying. Alas! In the beginning of teaching, one must make things easy for people to understand. If one immediately demands from them the difficulty of sagely wisdom and subtle skill, then the more they seek, the more they weary themselves; the more they probe, the more confused they become—how is this different from what Wang Tong said about not being able to hastily discuss the Book of Changes? Someone says: Calculations in the temple hall are not without difficulty—why are they not placed at the end of the text? It is answered: The difficulty of calculations lies in taking the five matters as a guiding framework and comparing them with the seven calculations to seek out the enemy’s situation. The enemy’s situation is the most difficult to know; it cannot be obtained from ghosts and spirits, cannot be inferred from things by their signs, and cannot be verified by measurements. Knowing the enemy’s situation in advance must rely on spies. Generally speaking, calculations await the enemy’s situation before comparison, and the enemy’s situation relies on spies before it is known. It is reasonable to consider spying profound and calculations shallow. Sun Wu’s depth of thought reaches this point, and only then does one realize that the explanations of the ten commentators cannot exhaust it.

Thus ends the chapter.