《孫子遺說》

Interpretation of Sunzi's Lost Teachings

In his preface, Emperor Wu of Wei (Cao Cao) wrote: I have heard that in ancient times, the power of the bow and arrow was highly valued. The Analects emphasize the importance of military preparedness, the Book of Documents lists warfare as one of the eight essential policies, the Book of Changes states that armies must act with righteousness and commanders must be wise, and the Book of Songs records how King Zhou rallied his troops in righteous fury. The Yellow Emperor, Tang of Shang, and Wu of Zhou all used force to save the world. The Methods of the Sima declares: "Those who kill without cause may be put to death." Relying solely on military might leads to ruin (as with King Fuchai of Wu), while excessive reliance on benevolence also brings downfall (as with King Yan of Xu). The sages used warfare to end war, resorting to arms only when absolutely necessary.

I have studied many military texts, but Sunzi’s work stands out as the most profound, with strategies that are meticulously detailed. Yet, most people fail to grasp its depth, and the various commentaries have become overly convoluted, obscuring the original essence. That is why I have compiled this concise annotation.

The Biography of Sunzi records: Sun Wu, a native of Qi, presented his Art of War to King Helü of Wu. The king said, "I have read all thirteen chapters of your military treatise. Can you demonstrate them on a small scale?" Sunzi agreed, and the king asked, "Can we use palace maidens for the drill?" Sunzi replied that it was possible.

So, 180 palace women were selected and divided into two units, with the king’s two favorite concubines appointed as captains. Sunzi instructed them: "Do you know where your heart, left hand, right hand, and back are?" The women answered yes. Sunzi explained: "When I say 'forward,' face your heart; 'left,' face your left hand; 'right,' face your right hand; 'back,' face your back." He then set up execution tools and repeatedly stressed discipline.

At the first drumbeat signaling a right turn, the women burst into laughter. Sunzi said, "If orders are unclear, the fault lies with the commander." After repeating the instructions, at the second drumbeat for a left turn, the women laughed again. Sunzi declared, "Since the rules were made clear and still disobeyed, the fault now lies with the soldiers." He ordered the execution of the two captains.

The king urgently sent a messenger to intervene: "I recognize your skill as a general. Without these two consorts, I cannot enjoy my meals—spare them!" Sunzi replied, "A general in the field may disregard the sovereign’s commands." He proceeded to execute the two captains and appointed replacements.

This passage recounts the stories of two military strategists, Sun Wu and Sun Bin:

When Sun Wu trained palace maids in military formations, their advancing, retreating, kneeling and rising all followed regulations without any daring to make a sound. Reporting to the King of Wu, Sun Wu declared the troops were now disciplined enough to obey orders even through fire and water. Yet the king declined to inspect them, prompting Sun Wu to lament that the ruler only enjoyed empty talk without recognizing true talent. Later, King Helü of Wu, realizing Sun Wu's genuine military prowess, appointed him as general. Consequently, Wu crushed the powerful Chu state in the west, penetrating its capital Ying, while intimidating Qi and Jin in the north, gaining renown among the feudal lords (According to Yuejue Shu, Sun Wu's tomb lies ten li outside Wumen Gate in Wu County).

Over a century later, Sun Bin was born in the A-Juān region as Sun Wu's descendant. He once studied military strategy alongside Pang Juan. After Pang Juan became General under King Hui of Wei, jealous of Sun Bin's superior ability, he framed his rival. Through judicial punishment, Sun Bin had his legs amputated and his face tattooed with criminal marks. When Qi's envoy later visited Wei, Sun Bin secretly sought an audience. Recognizing his extraordinary talent, the Qi emissary smuggled him back to Qi. General Tian Ji of Qi, deeply impressed, treated Sun Bin as an honored guest.

Tian Ji often raced horses with Qi nobility for wagers. Observing the horses' comparable strengths, Sun Bin advised Tian Ji to: match his inferior horses against the opponent's best, his best against their medium, and his medium against their inferior. This strategy of losing one round but winning two ultimately earned Tian Ji a thousand gold pieces. Consequently, Tian Ji recommended Sun Bin to King Wei of Qi, who consulted him on military tactics and appointed him as chief strategist.

When Wei later attacked Zhao, Zhao sought Qi's assistance. Though King Wei wished to appoint Sun Bin as commander, Sun Bin declined due to his physical disability. Thus Tian Ji led as general while Sun Bin, riding in a supply wagon, devised strategies as military advisor.

(Note: "Tattooing" refers to the ancient punishment of facial branding; "physically punished person" denotes those disabled by judicial mutilation; "supply wagon" indicates ancient cargo transport vehicles)

This passage recounts two famous military stratagems employed by Sun Bin (also known as Sunzi the Strategist) to defeat the Wei state. I'll explain both events in plain language:

【Battle of Guiling】

When Tian Ji wanted to lead troops to rescue Zhao, Sun Bin advised: "You can't untangle knotted threads by brute force, nor stop a fight by taking sides directly. Warfare requires striking at vital points and exploiting weaknesses. Right now, Wei's elite forces are all deployed against Zhao, leaving only the old and weak to defend their capital Daliang (modern Kaifeng). We should swiftly attack Daliang and cut their supply routes. The Wei army will have to abandon Zhao to defend home, achieving two goals at once." Tian Ji followed this plan. As predicted, the Wei forces withdrew from Handan and suffered a crushing defeat by Qi troops at Guiling.

【Battle of Maling】

Fifteen years later, when Wei and Zhao jointly attacked Han, Qi again sent Tian Ji to assist. Sun Bin suggested: "The Wei army has always underestimated Qi troops—we'll use this against them. Military doctrine states that marching 100 li in haste will exhaust commanders, while 50 li will make half the troops straggle. We'll feign retreat—dig 100,000 cooking pits the first day, 50,000 the second, and 20,000 the third." Wei general Pang Juan took the bait, believing Qi forces had deserted in droves, and pursued recklessly with light troops.

Sun Bin calculated Pang Juan would reach Maling (modern Tancheng, Shandong) at dusk, where mountain paths narrowed. He had tree bark peeled to carve "Pang Juan dies beneath this tree" and hid 10,000 archers. When Pang Juan lit torches to read the inscription at night, arrows rained down, throwing Wei troops into chaos. Realizing his fatal mistake, Pang Juan drew his sword saying, "So this is how I make that brat famous!" before committing suicide. Qi forces annihilated the Wei army and captured Crown Prince Shen of Wei, cementing Sun Bin's legendary reputation.

The concluding excerpt from the "Preface to Lost Sayings of the Ten Commentators on Sunzi" conveys: The deeper one studies military strategy, the more one discovers its profound subtleties; the more one inquires, the more unfathomable it appears. Like the Dao (Way) of warfare—seemingly simple yet containing infinite wisdom.

Here is the translation following your guidelines:

This represents the most profound military theory in the world—establishing principles and expounding truths with inexhaustible depth, thereby serving as a model for contemporary instruction and transmission to future generations. Confucian scholars often lament the inscrutable profundity of the Book of Changes (Yijing), just as students of military strategy struggle with the subtle intricacies of Sunzi's Art of War—are they not equally profound?

The Book of Changes encompasses the Three Powers (Heaven, Earth, and Humanity) and embraces all phenomena, with the unfathomable transformations of Yin-Yang constituting its spiritual essence. Thus the benevolent perceive benevolence, the wise discern wisdom, while common people use it daily without conscious awareness. Sunzi's Art of War systematizes four strategic dimensions (note: likely referring to categories like "the Way, Heaven, Earth, Commanders, and Methods") and synthesizes hundreds of military schools, taking the mutual generation of orthodox and unorthodox tactics as its marrow. Thus strategists perceive stratagems, tacticians recognize techniques, yet even the Three Armies employing them cannot fully comprehend their depths.

Though later generations produced commentaries from nine masters and a hundred schools, it was like observing the movements of sun, moon and stars without grasping their spiritual nature. After ten major annotations appeared—while exhaustively analyzing the thirteen chapters' variations like the five tones and colors—they still couldn't completely master its subtleties. Thus Sun Wu's true meaning wasn't fully expressed by these ten commentaries. Yet students of military strategy cannot begin without them—like following a stream to its source or entering through side paths, these annotations remain essential guides.

During leisure hours, I (Zheng Youxian) contemplated Sunzi's subtle principles and addressed several dozen unanswered questions from the ten commentaries, presenting key insights in question-and-answer format as Supplementary Explanations to the Ten Commentaries. When scholars see these overlooked perspectives, they'll recognize how Sunzi's Art of War indeed contains the same inexhaustible marvels as the Book of Changes.

[Q&A Section]

Question: "Why discuss 'the ground of life and death' before 'the Way of survival and destruction'?"

Sunzi's meaning: War hinges on selecting capable commanders. With competent commanders, armies triumph and return alive—their external survival ensures the state's internal preservation. With inept commanders, armies meet defeat and annihilation—their external destruction brings the state's internal collapse. Thus external life-and-death directly determines internal survival-and-ruin.

The Lost Teachings of Sunzi primarily discusses the importance of military command and strategic decision-making, as well as the flexible application of military tactics.

The first section recounts how the state of Zhao perished after its crushing defeat at the Battle of Changping, and how the Sui Dynasty collapsed following its failure in the Liao River campaign. The Grand Duke (Jiang Ziya) once said that a general who relies solely on brute courage and reckless warfare, lacking wisdom and strategy, will lead to the disintegration of the army and the peril of the state. Therefore, rulers must be cautious in selecting their commanders. A true master of warfare is the people’s safeguard and the linchpin of a nation’s security.

The second section examines the concept of "calculating advantages." Sunzi’s Art of War speaks of the "Five Fundamentals" (Dao, Heaven, Earth, Command, Discipline) and the "Seven Comparisons" (assessing seven key aspects of superiority and inferiority between oneself and the enemy). If three or four of these are met, it is considered "advantageous"; if only one or two are met, it is deemed "disadvantageous." If all Five Fundamentals and Seven Comparisons are satisfied, it leads to "total victory," while meeting none results in "no calculation" (utter lack of advantage). Those who rush into battle without calculation, hoping for a stroke of luck, are merely gambling with fate.

The third section explains that the application of military strategy must adhere to established principles while also adapting to circumstances. Military texts can only outline fixed rules, but actual combat demands flexibility. The "Five Fundamentals and Seven Comparisons" are fundamental laws, while "deceptive tactics" (strategic variations) cannot be rigidly taught. Fighting by the book alone is like trying to play a zither with glued tuning pegs or driving a horse by following a manual—Zhao Kuo (the archetype of armchair strategists) memorized texts but failed to adapt. When Sunzi first offered his counsel to the state of Wu, he feared the king might only study the book without employing him, so he emphasized that beyond the text lies the art of "adapting advantage to seize opportunity."

The fourth section explores the distinction between "relying on the enemy for provisions" (acquiring supplies from the foe) and "drawing equipment from one’s own state" (weapons must be self-prepared). Weapons cannot be lent to others, nor can the enemy’s arms be used, because each soldier is accustomed to the length and weight of their own gear—only familiar weapons can unleash full effectiveness. The enemy’s weapons are ill-suited to us, just as ours are to them.

The Sunzi Yishuo discusses the hierarchy of military strategy and the art of warfare:

On military preparedness:

How can a state rely on borrowing others' weapons in emergencies? The Yijing states, "Prepare arms to guard against the unexpected," while Jiang Taigong noted, "Without prior preparation, equipment will be incomplete." Both emphasize that weapons and supplies must be self-sufficient.

On strategic hierarchy:

1. The highest form is "conquering through stratagem" (伐谋)—subduing enemies without bloodshed by outmaneuvering their plans.

2. The middle tier involves "defeating enemy troops" (伐兵) and "storming fortifications" (攻城).

3. The lowest is "undermining alliances" (伐交), relying on diplomatic means.

Rationale:

• Foiling an opponent's schemes achieves victory without cost.
• Diplomatic efforts require upfront investment (envoys, bribes, spies). For instance, Zhang Yi spent years dissolving the Six-State Alliance, and Wei Liaozi expended 300,000 taels of gold to sabotage reinforcements—both demanded heavy resources.

Key insights from The Art of War:

While most chapters detail tactics, two stand out:

1. Offensive Strategy: Ideal victory is total; partial triumph is secondary. Mastery preserves all forces; misapplication may sacrifice a third of one's troops.

2. Maneuvering Principles: Turn detours into shortcuts, adversity into advantage. Skillful execution achieves "late departure, early arrival"; failure incurs heavy losses.

Final emphasis:

To prevail under Heaven, pursue flawless victory—yet the crux lies in mastering battlefield maneuver. Thus, these methods demand meticulous study. True triumph avoids brute force: render enemies passive, making strongholds crumble unassailed.

(Note: Military terms like 伐谋 are translated contextually while preserving core concepts; Chinese philosophical texts often use layered metaphors.)

This passage explains several key principles from ancient military strategy in modern terms:

On the relationship between a general's competence and sovereign control:

• Sun Tzu's Art of War states that "when a general is capable and the sovereign does not interfere, victory is assured." Historical cases from Emperor Taiwu of Northern Wei and Emperor Shenwu of Northern Qi demonstrate that respecting a general's autonomous decision-making often leads to victory, while forced interference mostly results in defeat. However, there's a deeper implication: if the general lacks ability, appropriate guidance from the sovereign can turn the tide.
• Outstanding commanders treat generals differently based on their competence: granting battlefield autonomy (kuanji, delegated authority) to capable officers, while providing detailed battle plans (chengsuan, prearranged strategies) to those less competent. Like Cao Cao's military approach—giving only general directives to skilled commanders like Zhang Liao and Yue Jin, while granting complete autonomy to supreme talents like Xiahou Dun and his brother.

On "victory can be anticipated but not forced":

• When enemies maintain strict vigilance (no xin, openings), we cannot forcibly create winning conditions—this is the "cannot be done" scenario. But when enemies reveal vulnerabilities (having xin), seizing the opportunity brings victory—this is the "can be known" scenario.
• Tactics like exhausting enemies through maneuvering (lao zhi, wearing them down) or sowing discord among them (li zhi, dividing them) all require opponents to first expose exploitable weaknesses. If the enemy ruler is wise and generals are astute (zhu ming jiang zhi, enlightened leadership and intelligent command), forcing victory becomes extremely difficult.

(Note: Here "xin" refers to vulnerabilities or exploitable opportunities; "kuanji" means delegating military authority to field commanders; "chengsuan" denotes detailed operational plans.)

The Sunzi's Lost Teachings passage discusses two key aspects of military strategy:

The first section explains how to exploit an enemy's weaknesses. When internal conflicts arise within the enemy camp (like King Chu's incompetence and Minister Nangwa's corruption), persistent harassment can exhaust them. Similarly, when facing a tyrant like Xiang Yu with narrow-minded advisors like Fan Zeng, counterintelligence tactics become effective. True strategy lies in foreseeing latent conflicts during the enemy's periods of stability, then implementing fatigue and division tactics when vulnerabilities emerge. Only enemies without internal contradictions prove truly formidable.

The second section presents four interpretations of offense/defense principles:

1. Cao Cao held: Defense indicates insufficient strength, offense indicates surplus strength

2. Li Quan believed: Defend when strength is lacking, attack when strength is abundant

3. Duke Weiguo argued: Offense/defense aren't simple matters of strength

4. Emperor Taizong of Tang maintained: Defense should feign weakness, offense should display strength

In truth, offensive/defensive tactics depend not on absolute strength but on flexible adaptation to circumstances. "Insufficiency" refers to concealing capabilities to confuse enemies; "surplus" means striking decisively when opportunities arise. Defense should be as hidden as beneath the ninefold earth (jiudi), while offense should strike as suddenly as thunder from the ninefold heavens (jiutian).

The final section discusses "unorthodox/orthodox" (qizheng) tactics. Sunzi particularly emphasizes their transformative importance as the key to maintaining battlefield invincibility. Though not explicitly stated, these tactical variations clearly constitute the primary method for overcoming adversaries.

(Note: Qizheng refers to coordinated use of conventional and unconventional tactics; the ninefold earth/heaven metaphors represent extreme concealment and overwhelming force respectively)

"Sunzi's Supplementary Teachings" Interpreted in Plain Language:

Regarding military strategy, it mentions that conventional forces (zheng bing) are responsible for frontal engagement, while unconventional forces (qi bing) achieve victory through surprise tactics. The role of conventional forces is to withstand enemy attacks, while unconventional forces ensure invincibility. Using conventional forces to engage the enemy and unconventional forces to secure victory—isn't this principle perfectly clear?

Someone asked: Since military strategy speaks of the interdependence of conventional and unconventional tactics, why does it particularly emphasize "those skilled in employing unconventional tactics"? This is due to textual conciseness. Just as heaven and earth, rivers, sun and moon, the four seasons, the five colors, and the five flavors all embody characteristics of boundlessness and mutual transformation, the text first discusses conventional engagement and unconventional victory, ultimately concluding that the variations between conventional and unconventional tactics are endless, like an inexhaustible cycle. How could relying solely on unconventional tactics produce infinite variations? It should be said that only those skilled in employing the interplay of conventional and unconventional tactics can achieve transformations as limitless as heaven and earth.

Someone asked: The meaning of "creating a posture of overwhelming momentum" is easy to grasp, but what is the essence of "delivering blows with precise timing"? The answer is: No matter how strong the force, if one fails to control the rhythm and timing of short-distance strikes, it will be difficult to inflict damage. Take the thinnest Lu gauze—even a powerful crossbow cannot pierce it at the end of its trajectory; or the lightest feather—after a long gust of wind, even a bird of prey cannot be lifted. Though the momentum may be fierce, after prolonged dissipation, even the wings lose strength—how then can one attack and destroy? Historically, Qu Yi defeated Gongsun Zan by setting an ambush within a few dozen paces, and Zhou Fang overcame Du Zeng by launching a charge from thirty paces away—this illustrates the principle of "delivering blows with precise timing."

Someone asked: Are all thirteen chapters of The Art of War written strictly according to their titles? The answer is: Each chapter's main theme closely follows its title without digression. Take the chapter on "Weakness and Strength" for example—from beginning to end, it discusses the application of weakness and strength, albeit expressed differently. The core idea is simply this: either we are strong (shi) while the enemy is weak (xu), or we are weak while the enemy is strong. A brilliant commander can transform strength into weakness and weakness into strength. Though the variations are myriad, the key lies in these two words: weakness and strength. Awaiting the fatigued at one's ease is strength; rushing to respond is weakness. Manipulating the enemy creates their weakness; not being manipulated by the enemy maintains our strength.

This passage elucidates the Dao of applying "substantial and insubstantial" (虚实) in military strategy:

The so-called "benefiting them" refers to luring enemies into weakened states; while "harming them" means strengthening our own position. The ability to fatigue well-rested enemies, starve well-fed troops, and destabilize settled forces arises from our grasp of substantiality (advantage) while the enemy remains in insubstantiality (disadvantage). When facing formidable enemy forces, we must devise methods to weaken them.

Troop movements should target undefended areas—this means exploiting enemy vulnerabilities to enhance our advantages. Attacking where enemies don't defend exemplifies avoiding the substantial to strike the insubstantial; defending where enemies won't attack demonstrates consolidating strength against weakness. Making enemies uncertain where to defend means attacking their insubstantial aspects; keeping them confused about where to attack signifies maintaining our substantial positions.

Achieving formlessness and soundlessness represents the consummate application of substantial-insubstantial dynamics. Invincibility stems from targeting enemy defensive weaknesses; being untraceable results from accumulated substantial strength. Striking where enemies must respond leverages their insubstantiality; altering enemy movement directions manipulates their misjudgment of substantial-insubstantial conditions.

Through reconnaissance, probing, and feints, we discern enemy substantial-insubstantial states. Gain, movement, vitality, and surplus manifest "substantial" qualities; loss, stillness, stagnation, and deficiency reveal "insubstantial" aspects. We must keep enemies ignorant of our shifting substantial-insubstantial transformations while ensuring our own troops remain unaware of our victory methods.

Like water flowing according to terrain, military operations must adapt to enemy circumstances for victory. In the Five Phases' mutual conquest, the conquering element represents substantiality while the conquered shows insubstantiality. Among seasonal transitions, the arriving season is substantial, the departing one insubstantial. Long daylight hours are substantial, short ones insubstantial; full moons substantial, waning moons insubstantial. These all manifest substantial-insubstantial transformations that cannot be rigidly constrained.

This passage reveals the fundamental principles of substantial-insubstantial dynamics in military strategy. The other twelve chapters all develop from this foundational Dao, though commentators have failed to explain it thoroughly.

Someone asks: Armies contend for advantage to achieve victory, yet when the entire force contends recklessly, it courts danger. Between military forces and common people, between benefit and peril—are the principles governing these truly distinct? The answer is: Sun Tzu's discourse never speaks idly; every phrase carries profound meaning. What is called "the army contends for advantage" refers to the "methods of military contention" discussed later—the principles for seizing initiative in battle. Only by contending according to these methods can one gain superiority over the enemy. As for "mass contention brings peril," this refers to "the entire army contending for advantage" mentioned subsequently. If the whole force rushes forward blindly, not only will it fail to gain benefit, but it will instead plunge into danger. For "military contention" follows the ordered contention of strategy, while "mass contention" is the reckless advance of the entire army. The former enables one to arrive late yet strike first, while the latter may lead to the capture of the three armies' commanders.

Someone asks: The art of war establishes itself through deception, moves through advantage, and transforms through division and combination. Must these three be applied in sequence? The answer is: While the governing principles of ancient sage-kings and the military methods of strategists both follow sequences of root and branch, first and last, what they honor differs fundamentally. The way of sage-kings honors benevolence and righteousness, supplemented by expediency; the methods of strategists value deception and advantage, ultimately returning to transformation. The Methods of Sima takes benevolence as its root, while Sun Tzu establishes himself through deception; the Methods of Sima governs armies through righteousness, while Sun Tzu motivates through advantage; the Methods of Sima employs expediency only when the proper way fails, whereas Sun Tzu directly uses division and combination as his means. Governance that honors benevolence necessarily emphasizes moral principles, while warfare that advocates deception necessarily seeks advantage. What sages call "expediency," strategists term "transformation." Without fundamental principles, one cannot cultivate oneself; without governing methods, one cannot seize opportunities; without expedient means, one cannot overcome the enemy. First establish the root, then you can govern action; able to govern action, then you can apply expediency. Expediency serves to assist action, and action serves to implement the root. This is the similarity in their sequences of root and branch, first and last.

Someone asks: Sun Tzu's discussions of troop deployment all concern military strategy—why particularly emphasize this method of commanding large forces? The answer is: Sun Tzu's art of war emphasizes the mutual generation of orthodox and unorthodox tactics (zheng and qi), employing both regulation and expediency without limit. It requires using orthodox troops' discipline to govern the army, while employing unorthodox troops' expediency to defeat the enemy. When discussing "strategic power" (shi), he places troop organization (fen shu) and command signals (xing ming) first—these represent the regulation of army governance; while the transformations of void and substantial, orthodox and unorthodox constitute the expedient stratagems for overcoming the enemy.

The Sunzi's Lost Teachings passage discusses two crucial aspects of warfare: first establishing control over one's own troops, then devising strategies against the enemy.

It begins with "discipline" (the fundamental method of troop management): using drumbeats and banners to unify command, ensuring soldiers move in unison—preventing the brave from reckless advancement and the timid from retreating. While this forms the foundation of military organization, it alone cannot achieve extraordinary victories.

Then comes "adaptation" (the flexible strategy of response): the need to disrupt the enemy's perception and break their morale. Specifically:

1. Against common soldiers, target their "Qi" (fighting spirit)—as illustrated by the classic "single drumbeat momentum" principle, where repeated defeats drain their courage

2. Against commanders, target their "Xin" (decision-making capacity), causing them to misjudge complex battlefield situations

The text particularly emphasizes: supreme military mastery lies in recognizing seemingly contradictory opportunities. For example:

• While "avoid attacking uphill" is standard advice, sometimes precisely such attacks are necessary
• While "never pursue feigned retreats" is the rule, sometimes pursuit becomes the winning move
• While "don't take the bait" is conventional wisdom, sometimes playing along becomes the superior tactic

The truly brilliant strategist discerns opportunities when others hesitate, applying military principles with transcendent skill. This resembles masterful chess players who both follow established theory and know when to break conventions in special circumstances.

The Sunzi's Supplementary Teachings primarily discusses the flexible application of military strategies and the tactical use of nine types of terrain.

Regarding military principles: Though military texts often state "when surrounding the enemy, leave them an escape route" and "do not pursue desperate foes," in actual combat, there are situations where one may not leave an opening or may choose to pursue. Truly exceptional commanders do not rigidly adhere to doctrine but make flexible decisions based on specific circumstances—this is the subtle essence of military strategy.

Concerning the "Nine Variations" tactics: Some ask, what are the "Nine Variations"? These refer to the methods for handling nine types of terrain. Specifically, they include:

• Scattered Ground (本国领土, within one’s own territory),
• Light Ground (刚进入敌境, just entering enemy territory),
• Contested Ground (兵家必争之地, strategically vital terrain),
• Intersecting Ground (道路交错处, areas with crisscrossing roads),
• Pivotal Ground (多国交界处, borders of multiple states),
• Heavy Ground (敌境纵深, deep in enemy territory),
• Difficult Ground (难行之地, treacherous terrain),
• Encircled Ground (易被包围处, terrain prone to encirclement),
• Fatal Ground (进退无路之地, terrain with no retreat).

For each of these, different strategies are required: unifying morale, strengthening communication, rapid movement, cautious defense, consolidating alliances, securing supply lines, selecting routes, blocking gaps, and demonstrating resolve to fight to the death.

Why are only five listed when it's called the "Nine Variations"? Likely due to omissions in transmission. Commanders must master the variations of these nine terrains—otherwise, even if they recognize the terrain, they will fail to exploit its advantages. The core of the Nine Variations lies in adapting flexibly to terrain characteristics, just as different terrains demand different approaches: knowing the terrain but not its name leads to blind decisions; knowing the name but not its variations results in chaotic command; knowing the variations but not the tactics leads to defeat in battle.

The author criticizes Li Quan for mistakenly equating the "Five Advantages" (五种有利条件) with the "Ten Variations." Additionally, it clarifies that "do not linger in dire terrain" (绝地无留) likely refers to "Light Ground" (刚入敌境), as such terrain has the characteristic of "no prolonged stay" (无止).

Regarding encampment elevation: Some ask why military texts advocate high ground for encampments, yet Jiang Taigong warned that armies stationed on high mountains are easily besieged. The answer is: Sunzi’s "high ground" and Jiang Taigong’s refer to different things. Jiang Taigong meant exceptionally steep peaks, while Sunzi referred to generally advantageous terrain.

This passage primarily discusses the relationship between military terrain selection and the art of command.

Regarding terrain selection:

Camping on barren high ground is perilous, as the lack of vegetation means scarce provisions, and supply lines become vulnerable when surrounded by enemies. Such terrain permits only temporary occupation, not prolonged stationing. However, Sunzi (Sun Wu) argues that occupying elevated hills can instead confer advantages: enemies must attack uphill, while defenders can leverage the high ground to launch assaults like pouring water from a roof or rolling boulders downhill. The key lies in securing supply routes—this enables offensive momentum, defensive stability, ample provisions during encampment, and safe retreat paths. The text cites the example of Emperor Taiwu of Northern Wei trapping Yao Xing of Later Qin at Tiandu by cutting supply lines, demonstrating how even forces holding high ground can be crippled without logistical support.

Regarding command:

The author emphasizes that terrain is merely auxiliary—true victory hinges on leadership. Jiang Taigong (Taigong) believed commanders should delegate terrain reconnaissance to specialists. Exceptional leaders must: calmly assess enemy situations, make sound decisions, and direct troops flexibly. The text lists six causes of defeat—"flight, slackness, collapse, entrapment, disarray, rout"—all stemming from command errors. The application of nine terrain types also requires balancing firmness and adaptability. A true master of command guides troops like a shepherd leading sheep, accomplishing objectives without soldiers even realizing it.

Core arguments:

1. High-ground warfare demands secure supply lines

2. Terrain is secondary—victory depends on command ability

3. Skilled commanders excel in judgment, decision-making, and concealing intent

4. Military failures stem more from command mistakes than unfavorable terrain

The Sunzi's Lost Teachings passage discusses two key points about military psychology and tactical application in warfare:

The first section explains the principle of "placing troops in mortal danger to ensure their survival." Sunzi argues that when an army is trapped in a desperate situation with no retreat, soldiers who no longer fear death will naturally spare no effort in battle. When people refuse to retreat even when facing the most difficult choice (such as death), relatively easier tasks (like fighting with full strength) become trivial by comparison. Previous commentators who separated the phrase "death being unavoidable, soldiers exert full effort" into two distinct statements have misunderstood Sunzi's original intent.

The second section examines the tactic of "releasing horses and burying chariot wheels." While some interpret "fang" (方) as "tying," the author suggests it should mean "releasing" (放). Sunzi's point is this: if troop morale has collapsed, even coercive measures (like releasing warhorses or immobilizing chariot wheels) cannot prevent disintegration. Just as chariots become useless without horse traction or when wheels sink in mud, soldiers will still scatter and flee. The true solution lies in proper military discipline to unify the soldiers' will.

The third segment distinguishes between "military psychology" (兵情) and "military actions" (兵事): "Qing" refers to hidden, unpredictable psychological factors, while "shi" denotes observable concrete actions. The art of warfare lies first in understanding soldiers' psychology (qing), then taking corresponding actions (shi). The saying "in military psychology, speed is paramount" emphasizes the critical advantage of seizing this psychological momentum for swift decision-making.

This passage from Master Sun's Lost Teachings discusses several key principles of military strategy:

The first section elucidates the essence of "striking where unexpected" tactics. Truly masterful military operations should resemble divine swiftness, attacking when the enemy is completely unprepared and unable to mount defenses. The crux lies in maintaining absolute secrecy—even the most astute spies cannot detect preparations in advance. When vulnerabilities appear in the enemy's position, one must concentrate forces for a lightning strike across great distances to eliminate opposing commanders, leaving the enemy no time to deploy formations or defend their cities. This "skillful accomplishment" fundamentally depends on precise intelligence assessment and impeccable timing.

The second section examines the concept of "desperate terrain" (绝地). This refers to situations where an army has crossed borders into hostile territory with severed supply lines. Ancient military codes mandated "severing correspondence" (书绝) to prohibit soldiers from looking backward—even prescribing capital punishment for deserters—all to eliminate any thought of retreat. However, desperate terrain isn't classified among the nine standard tactical terrains because it offers no room for adaptive maneuvering.

The third section emphasizes three indispensable campaign requirements: understanding neighboring rulers' intentions, mastering terrain knowledge, and employing local guides. The author explains why these are repeatedly stressed in both the Military Maneuvers and Nine Terrains chapters—they determine route selection (converting circuitous paths into direct advances) and the risk-reward calculus of deep penetration, forming the foundation for "arriving late yet striking first" tactics. Particularly when operating in unfamiliar hazardous regions, reliance on allied support and terrain-savvy guides becomes essential.

(Note: The "nine terrains" refer to The Art of War's classification of nine combat zones with corresponding tactics; "follow-up forces" (踵军) denote subsequent troop deployments; "severed correspondence" (书绝) was an ancient military protocol cutting communication lines.)

The Sunzi's Lost Teachings passage discusses two key aspects of military strategy:

The first part addresses terrain tactics:

When marching through complex terrain like marshes and wetlands, relying solely on local guides without understanding the terrain's characteristics will inevitably lead to disorientation. It's like hunting without guides in dense forests or forcing horses through unfamiliar wilderness—how could one possibly gain battlefield initiative this way? Sunzi had already elucidated this principle in his first two chapters on military strategy.

The second part explores unconventional command methods:

When asked about "rewards beyond regulations" and "orders beyond norms," the text explains: While armies have standard reward-punishment systems, sometimes deliberately violating conventions can confuse enemies. Examples include:

1. Unconventional rewards: Wu Qi (referred to as "Master Wu") rewarded soldiers fleeing northward in full view of enemies; Ma Long (Western Jin general) preemptively rewarded troops before battles.

2. Unconventional orders: Li Su (Tang dynasty general who suppressed the Huaixi rebellion) constantly altered marching orders during his Caizhou surprise attack, keeping subordinates as disoriented as herded sheep.

On espionage tactics:

Employing spies (yongjian) requires extraordinary wisdom—objectives can be achieved through events or stratagems without necessarily dispatching agents. Handling spies (shijian) demands benevolence and righteousness: commanders must maintain loyalty through kindness and dispel mutual suspicions through moral principle. Examples include the King of Qin secretly nurturing Zhang Yi for years, and Emperor Gaozu of Han allowing Chen Ping unrestricted funds to recruit spies—both exemplify maintaining spy relationships through grace and righteousness.

(Note: "Master Wu" refers to Wu Qi; Ma Long was a famous Western Jin general; Li Su was the Tang dynasty general who pacified the Huaixi rebellion.)

The Sunzi's Additional Teachings passage primarily discusses the distinction between "strategic flexibility" (quanbian) and "espionage" in military strategy, as well as the progressive nature of pedagogical methods.

The text begins with examples of Yi Yin (Yi Zhi) and Jiang Ziya (Lü Ya), illustrating how ancient sages achieved great deeds by employing strategic flexibility when orthodox methods proved ineffective. Both figures infiltrated the Xia and Shang courts respectively—actions that might appear as espionage but were in fact manifestations of "strategic flexibility," since their ultimate goal was to return to the proper path. In contrast, the "espionage" discussed in military treatises often leads to irreversible deception. Though their essence is the same, they differ in name and outcome.

When asked why the discussion of "espionage" is placed at the end of military texts, the author explains: Among military methods, espionage is the most profound and subtle. Teaching must follow a gradual progression, starting with straightforward calculations and comparisons, then advancing to tactics of attack and defense, assessing circumstances and identifying weaknesses. Only after mastering fundamentals like troop movement, terrain, and fire attacks can one engage with the deeper art of espionage. This mirrors how Sunzi, when instructing King Helü of Wu, began with simpler principles before delving into more advanced strategies.

The meaning of this passage is:

The Dao (the Way) is inherently simple and comprehensible, but if one hastily attempts to grasp its subtle and profound aspects using the wisdom of sages, the more one pursues it, the more confused one becomes. This is like what Wang Tong said about not abruptly discussing the profundities of the Yijing (Book of Changes). Someone asked: Isn't strategizing major affairs at court difficult? Why not save the most important matters for last? The response is: The greatest challenge in strategy lies in mastering the five fundamental elements (the "five factors": the Dao, Heaven, Earth, the commander, and discipline) and comparing the seven key aspects (the "seven comparisons": Which ruler embodies the Dao? Which general has greater ability? etc.) to discern the true situation. Yet, understanding the enemy's true situation is the most difficult—it cannot be achieved through divination, analogical reasoning, or subjective conjecture. Only those who truly know the enemy rely on spies (jian). Because strategies must be formulated based on actual conditions, and actual conditions can only be obtained through espionage. Thus, espionage should be regarded as the deeper layer of strategy, while general planning is the surface layer. Sun Wu's (Sunzi's) profound thought is fully revealed here, showing that the doctrines of the ten schools of thought cannot completely encompass it.

(Note: The "five factors" refer to the Sunzi Bingfa (Art of War) concepts of the Dao, Heaven, Earth, the commander, and discipline; the "seven comparisons" include questions like which ruler follows the Dao and which general is more capable; "jian" refers to espionage activities.)