第 1 章
The Decline of Violence: A Counterintuitive Truth
When Steven Pinker published "The Better Angels of Our Nature" in 2011, it quickly became Bill Gates' "favorite book of all time." This 800-page masterwork challenged humanity's deepest assumptions about violence and progress with a startling claim: despite news headlines suggesting otherwise, violence has been in dramatic decline throughout human history. The book's thesis proved so revolutionary that Barack Obama cited it in his Nobel Peace Prize acceptance speech, while Mark Zuckerberg featured it in his personal reading challenge. What makes this work so compelling is not just its counterintuitive premise, but Pinker's extraordinary ability to marshal evidence across disciplines-from psychology and neuroscience to history and anthropology-creating what The New York Times called "a masterly effort to explain what Mr. Pinker considers humanity's greatest moral achievement."
第 2 章
Our Violent Past: A Foreign Country
If the past is indeed a foreign country, it's a shockingly violent one. Evidence of humanity's brutal heritage surrounds us-from religious symbols of torture to common expressions like "whipping boy" and "rule of thumb" (originally referring to the maximum thickness of a stick a husband could legally use to beat his wife). Archaeological discoveries consistently reveal our violent prehistory: Otzi the Iceman, discovered in 1991, died from an arrow wound and had others' blood on his weapons. Kennewick Man had a stone projectile lodged in his pelvis. Lindow Man was ritually killed three different ways-skull fractured, neck broken, and throat cut.
This brutality wasn't limited to prehistoric times. The Iliad depicts warfare where Agamemnon explicitly orders the complete extermination of Trojans, "down to the babies in their mothers' wombs." The Hebrew Bible portrays a world of staggering savagery, with King David not just writing poetry but "cutting people with saws, harrows of iron, and axes" after conquering them. Even if many biblical atrocities never happened historically, these stories reveal the values of Near Eastern civilizations-a world where genocide was divinely sanctioned, women were sexual property, and slavery and cruel punishments were unremarkable.
The Roman Empire's celebrated Pax Romana existed alongside brutal imperial expansion and institutionalized cruelty. The Colosseum hosted mass spectacles where women were raped by animals, slaves enacted mythological deaths, and gladiators fought to the death-claiming roughly 500,000 lives for public entertainment. Crucifixion, Rome's signature execution method, inflicted unspeakable agony, with victims slowly dying from asphyxiation and blood loss over hours or days.
Medieval knights, far from the chivalrous heroes of modern imagination, were extraordinarily violent. The 13th-century romance "Lancelot" averages one act of extreme violence every four pages-skulls split open, knights crushed under war-horses, decapitations, and women bound in iron bands or kept in boiling water. Even the British royal family's history is particularly bloody, with Henry VIII beheading two wives and Elizabeth I torturing enemies with bone-crushing manacles.
Children's entertainment remained violent well into the 20th century. Punch and Judy puppet shows featured infanticide and wife-beating, while Mother Goose nursery rhymes contained shocking violence-featuring murder, child abuse, and mutilation at rates far exceeding modern children's television. Even the recent past can seem foreign-1950s television sitcom "The Honeymooners" played domestic violence threats for laughs, with Jackie Gleason's character regularly threatening "POW, right in the kisser!" to his wife.
第 3 章
The Pacification Process: From Anarchy to Order
Thomas Hobbes articulated a brilliant analysis of violence's incentives in Leviathan, identifying three principal causes of conflict: competition (for gain), diffidence (for safety), and glory (for reputation). These motivations are deeply embedded in evolutionary logic-competition for scarce resources like food, territory, and reproductive opportunities is inevitable among survival machines.
Sexual competition is particularly intense among males because female reproductive capacity is limited, making it a resource males compete over. This competition breeds fear (diffidence), creating a dangerous spiral where each party might strike preemptively to avoid being struck first-the "Hobbesian trap."
Evidence from both archaeological remains and ethnographic studies reveals strikingly high rates of violent death in nonstate societies. Prehistoric skeletal remains show an average of 15% of deaths were violent, with some populations reaching 60%. Contemporary hunter-gatherer societies show nearly identical rates (14% average), while hunter-horticulturalist societies averaged even higher at 24.5%.
By contrast, state societies show dramatically lower rates of violent death. Pre-Columbian Mexican empires had only 5% violent deaths-a third to a fifth the rate of typical nonstate societies. Even Europe's bloodiest periods-the 17th century Wars of Religion and the 20th century World Wars-saw only 2-3% of deaths from warfare. When comparing pre-Columbian Native American skeletons, hunter-gatherers showed signs of violent trauma at 13.4%, while city dwellers from Andean and Mesoamerican civilizations showed only 2.7%-a fivefold reduction in violence associated with living in a civilization.
Hobbes was largely right: without a common power to keep people in awe, they live in "continual fear, and danger of violent death." However, Hobbes got much wrong. People in nonstate societies extensively cooperate with kin and allies, making life far from "solitary" and only intermittently "nasty and brutish." The transition from foraging to civilization presented a complex trade-off. Early agriculturalists were physically worse off-archaeological evidence shows they were anemic, infected, tooth-decayed, and nearly two and a half inches shorter than hunter-gatherers. For those who did choose civilization, sacrificing health and stature seemed worthwhile for a fivefold better chance of not being speared.
第 4 章
The Civilizing Process: Europe's Remarkable Transformation
The dramatic decline in violence across European history represents one of the most remarkable yet overlooked transformations in human society. In 1981, political scientist Ted Robert Gurr revealed the stunning fact that homicide rates in England had plummeted by factors of ten to a hundred between the 13th and 20th centuries. This discovery contradicted popular perception-when surveyed, people guessed modern England was 14% more violent than medieval England, when in fact it was 95% less violent.
Historical criminologist Manuel Eisner expanded on Gurr's work by assembling a larger dataset of homicide estimates from English towns and jurisdictions across centuries. His findings confirmed the dramatic decline: from between 4 and 100 homicides per 100,000 people in the Middle Ages to around 0.8 per 100,000 by the 1950s. Similar declines occurred across Western Europe, though with varying timelines-Scandinavians took longer to reduce their homicide rates, and Italians didn't see significant drops until the 19th century.
Norbert Elias's theory attributes Europe's violence decline to a psychological transformation spanning several centuries. From the 11th-18th centuries, Europeans increasingly inhibited their impulses, considered long-term consequences, and developed empathy. A culture of honor gave way to a culture of dignity as people learned to control emotions rather than seek immediate revenge.
Two external factors drove this transformation. First, the consolidation of centralized monarchies created genuine Leviathans that brought warring knights under control. Europe had 5,000 independent political units in the 15th century but fewer than 30 by the mid-20th century. Kings had incentives to suppress violence that destroyed productive capacity and tax revenue. The second factor was an economic revolution. Medieval Europe's land-based economy was zero-sum-one person's gain required another's loss. But as trade expanded, positive-sum interactions emerged where both parties benefited from exchange. This "doux commerce" (gentle commerce) incentivized empathy and self-control, as merchants needed to understand and satisfy customers.
The main reason violence correlates with low socioeconomic status today is that elites and middle classes pursue justice through the legal system while lower classes resort to "self-help"-vigilantism and taking the law into their own hands when state intervention is absent. Donald Black's influential research shows that most crime is, from the perpetrator's perspective, the pursuit of justice. Most homicides are moralistic: retaliation after insults, escalation of domestic quarrels, punishing unfaithful partners, and acts of jealousy or revenge.
America stands as a statistical anomaly among Western democracies, with homicide rates closer to Albania and Uruguay than to Britain or Germany. This American exceptionalism isn't simply about gun ownership-even non-firearm homicides occur at higher rates than in Europe. The key insight is that America isn't one country regarding violence but three. The northern states have European-like homicide rates below 3 per 100,000. A north-south gradient exists, with southern states having rates comparable to developing nations, while Louisiana (14.2) approaches Papua New Guinea levels.
第 5 章
The Humanitarian Revolution: The Birth of Human Rights
The Museo della Tortura in San Gimignano, Italy displays a shocking collection of medieval cruelty that would disturb even those familiar with modern atrocities. The museum showcases instruments like Judas's Cradle (a sharp wedge victims were lowered onto), the Virgin of Nuremberg (a spike-lined iron maiden), and the Cat's Paw (flesh-ripping hooks). Such torture museums exist throughout Europe, displaying hundreds of devices that represent not isolated incidents but institutionalized sadism woven into medieval public life.
Medieval Christendom was truly a culture of cruelty, with torture codified in laws prescribing mutilation for minor crimes. Executions were public spectacles of sadism featuring prolonged killing through burning, breaking on the wheel, impalement, disembowelment, and slow hanging. The Christian church itself inflicted sadistic tortures during inquisitions, witch hunts, and religious wars.
This chapter examines the remarkable transformation that left us horrified by these practices. In the modern West, capital and corporal punishments have been eliminated, governments' power to use violence curtailed, slavery abolished, and the thirst for cruelty diminished. This progress began in the Age of Reason (17th century) and crested with the Enlightenment (late 18th century), propelled by both explicit arguments against institutionalized violence and changing sensibilities as people began to sympathize with fellow humans.
Witch hunts eventually succumbed to common sense. Throughout the Middle Ages, scattered clerics and politicians pointed out witches couldn't exist, though some skeptics were themselves tortured. During the Age of Reason, influential writers like Erasmus, Montaigne, and Hobbes strengthened these voices. Some officials conducted experiments-a Milanese judge who tortured his servant into falsely confessing to killing the judge's mule subsequently abolished torture in his court.
The 18th century marked a turning point for cruel punishments. English reformers began criticizing the "cruelty, barbarity, and extortion" in prisons. Public executions like Catherine Hayes's burning in 1726-where the executioner's failed strangling attempt left her struggling against flames for hours-began to disturb the public conscience. Prominent writers joined the critique. Voltaire called such practices barbaric and savage. Montesquieu highlighted Christian hypocrisy in condemning torture by Romans, Japanese, and Muslims while inflicting the same cruelty themselves.
Most influential was Cesare Beccaria, whose 1764 book "On Crimes and Punishments" influenced thinkers from Voltaire to Jefferson. Starting from the principle of "the greatest happiness of the greatest number," he argued punishment should only deter harm, be proportional to the crime's severity, and be certain and prompt rather than severe. He concluded that public trials based on evidence were essential and that the death penalty was unnecessary as a deterrent and beyond the proper powers of the state.
For most of civilization's history, slavery was the norm rather than the exception. It was sanctioned in Hebrew and Christian scriptures and justified by Plato and Aristotle as a natural, essential institution. "Democratic" Athens enslaved 35 percent of its population, as did the Roman Republic. While individual slaveholders throughout history sometimes freed their slaves, particularly upon death, a mass movement against chattel slavery as an institution first emerged in the 18th century and rapidly pushed it toward extinction.
The most compelling candidate for the exogenous change that triggered the Humanitarian Revolution is the growth of writing and literacy. Before Gutenberg's printing press in 1452, books were handwritten, expensive, and inefficient. After Gutenberg, publishing productivity grew twentyfold in two centuries. Book publication exploded in the 17th century and accelerated in the late 18th century, with literacy rates in England doubling during the 17th century. By century's end, most Englishmen could read and write, with similar trends across Western Europe.
第 6 章
The Long Peace: War's Surprising Decline
In the early 1950s, two British scholars made contrasting predictions about war's future. Historian Arnold Toynbee, having witnessed both world wars, pessimistically predicted an "ascending order of intensity" in warfare. Meanwhile physicist Lewis Richardson, analyzing statistical data from hundreds of conflicts, cautiously suggested "a long future may perhaps be coming without a third world war." History proved the obscure physicist right and the eminent historian wrong.
The claim that the 20th century was history's bloodiest is likely an illusion driven by two factors. First, the world's population was dramatically larger (2.5 billion by 1950, compared to just 560 million in 1600), meaning earlier conflicts must be scaled proportionally. Second, historical myopia makes recent events appear more significant than distant ones.
When adjusting for population size, fourteen of the twenty-one deadliest human atrocities occurred before the 20th century. The An Lushan Revolt during China's Tang Dynasty eliminated two-thirds of China's population and one-sixth of the world's-making it proportionally history's deadliest conflict. The Mongol invasions were particularly devastating, with Genghis Khan's forces massacring 1.3 million in Merv alone and 800,000 in Baghdad.
Richardson's groundbreaking discovery about warfare reveals that wars begin and end randomly, following a Poisson process. In such processes, events occur continuously, randomly, and independently, with intervals between events distributed exponentially-many short intervals and progressively fewer long ones. This mathematical reality explains why random events naturally appear clustered to human perception.
Jack Levy's dataset provides clarity by focusing on the modern era (late 1400s onward) and the great power system-those handful of states that dominate international affairs. When examining wars between these powers, the trend is unmistakably downward. The percentage of years with great powers fighting each other declined steadily from the 16th century, when some quarters saw conflict in all 25 years, to the present Long Peace, with no great power wars since the Korean War (1950-1953).
Both frequency and duration of wars involving great powers have declined dramatically. In the last quarter of the 20th century, only four wars met Levy's criteria, and they lasted an average of just 97 days-a stark contrast to the protracted Wars of Religion in earlier centuries.
What prevented World War III from happening, defying expert predictions and centuries of European warfare patterns? While many attribute this "most striking discontinuity in the history of warfare" to nuclear deterrence, this explanation falls short upon closer examination. The nuclear peace theory fails on several counts. First, history shows that weapons of mass destruction have never prevented wars before. Second, the theory can't explain why non-nuclear nations also stopped fighting each other. Third, Mueller argues that conventional deterrence was sufficient-World War II had already demonstrated how modern industrial warfare could kill tens of millions and reduce cities to rubble without nuclear weapons.
When the Democratic Peace debate devolves into sliding definitions and cherry-picked examples, statistical analysis becomes essential. Political scientists Bruce Russett and John Oneal revitalized the theory through rigorous quantitative testing, examining not whether democracies never fight (where each counterexample becomes existential) but whether they fight less often, all else being equal. The results strongly supported Democratic Peace theory: fully autocratic states doubled the chance of disputes compared to average country pairs, while fully democratic pairs reduced dispute risk by more than half.
第 7 章
The New Peace: Declining Violence in the Developing World
Despite the end of history's gravest threat-nuclear holocaust between superpowers-pundits remain remarkably pessimistic. Rather than celebrating the absence of predicted catastrophes, commentators like John Gray and others forecast "blood-soaked" returns to historical violence. This persistent gloom stems from market forces favoring pessimistic punditry, human nature's tendency to romanticize the past, and most significantly, innumeracy in intellectual culture that equates conflicts of vastly different scales.
Today's conflicts largely resemble opportunistic predation by small bands of criminals and thugs rather than professional armies. As Mueller describes it, these "entrepreneurs of violence" apply ethnic or religious rhetoric while essentially engaging in criminal activity. In Liberia's Civil War (1989-96), combatants adopted bizarre personas inspired by American action movies, calling themselves "Colonel Action," "General Rambo," or "General Butt Naked" while wearing strange attire from women's dresses to headgear made of toilet seats.
The recent decline in civil warfare likely reflects a "recivilizing process" where competent governments protect citizens rather than preying on them. Many African nations have replaced dictators with responsible leaders. International organizations, donor nations and the African Union have begun ostracizing incompetent tyrants while promoting measures against corruption. Democratic governments experience fewer than half the battle deaths of non-democracies in civil conflicts, and openness to global trade and investment appears to reduce both likelihood and severity of civil wars.
Genocide stands apart as the most heinous and incomprehensible form of human violence. The cold-bloodedness of genocidal perpetrators surpasses even the predatory violence of nature. As Dostoevsky observed about Turkish atrocities: "No animal could ever be so cruel as a man, so artfully, so artistically cruel." The psychological roots of genocide begin with our natural tendency to categorize people. Though categorization is essential to intelligence, allowing us to make inferences about others, it becomes dangerous when we forget categories are approximations, when we moralize our categories, and when we essentialize groups as sharing quasi-biological qualities.
Contrary to popular impression, the post-Cold War era has not seen a recrudescence of genocide. The peak in mass killing (excluding China in the 1950s) occurred from the mid-1960s to late 1970s, with Indonesia's anti-communist purge (700,000 deaths), China's Cultural Revolution (600,000), Pakistan's Bangladesh massacre (1.7 million), and Cambodia's killing fields (2.5 million). While the post-Cold War genocides in Bosnia (225,000 deaths), Rwanda (700,000), and Darfur (373,000) were atrocious, they represent spikes in a clear downward trend. The first decade of the new millennium has been the most genocide-free of the past fifty years.
Terrorism occupies a peculiar category of violence with a disproportionate ratio of fear to actual harm. Compared to deaths from homicide, war, and genocide, terrorism's toll is negligible-fewer than 400 annual deaths from international terrorism since 1968, and about 2,500 yearly from domestic terrorism since 1998. The 9/11 attacks were literally off the chart-in the extreme tail of the power-law distribution of terrorist attacks. Between 1970 and 2007, only one other attack worldwide killed as many as 500 people. During these 38 years, only 340 Americans died from terrorism on U.S. soil outside of 9/11, and just 11 after 9/11.
第 8 章
The Rights Revolutions: Expanding the Circle of Protection
The Rights Revolutions represent a cascade of campaigns that have stigmatized and criminalized various forms of violence, extending Western culture's distaste for violence further down the magnitude scale. These movements-civil rights, women's rights, children's rights, gay rights, and animal rights-emerged in tight sequence during the second half of the 20th century, each building on the tactics and moral rationales of its predecessors. Like an escalator, the concept of individual rights has continuously expanded to protect more categories of beings from harm.
The American civil rights movement's visible triumphs were preceded by crucial victories against intercommunal violence that had terrorized African Americans for a century after emancipation. Though lynching targeted African Americans most persistently, virtually every religious and immigrant group suffered deadly riots at some point. Lynchings and racial violence began declining dramatically from 1890 to the 1940s. The famous protest song "Strange Fruit" emerged paradoxically when the crime had already long been in decline. By the 1990s, FBI hate crime statistics showed racially-motivated murders had become vanishingly rare-just one per year in a country with 17,000 annual homicides.
The history of rape provides one of history's most shocking examples of how violence once considered acceptable is now recognized as an atrocity. Throughout history, rape was conceptualized not as a crime against the woman but against the man who "owned" her-father, husband, or slave owner. When European governments began nationalizing criminal justice, rape became a crime against the state, but the legal system remained heavily biased against victims. Women faced impossible burdens of proof, police treated complaints dismissively, and victims often found themselves effectively on trial alongside their attackers.
The revolution in rape laws came with the Enlightenment's recognition of women's rights and accelerated with second-wave feminism in the 1970s. Susan Brownmiller's 1975 book "Against Our Will" exposed society's historical indulgence of rape and challenged its romanticization in popular culture. Most dramatically, rape rates have fallen by an astonishing 80 percent between 1973 and 2008 according to the National Crime Victimization Survey, from 250 per 100,000 people to just 50. This decline has been steeper and more consistent than the general crime decline, suggesting that feminist activism against rape has been remarkably successful in changing both attitudes and behaviors.
Infanticide was historically widespread across cultures, with estimates suggesting between 10-50% of children in some societies were killed. Contrary to modern sensibilities, this practice was often considered "natural" rather than aberrant. The treatment of children improved gradually through history. Philosophers like Locke and Rousseau revolutionized thinking about childhood, rejecting the notion that children were inherently sinful and advocating for gentler treatment. By the early 20th century, children became "economically worthless but emotionally priceless." Modern anti-spanking movements have gained momentum, with approval of corporal punishment declining significantly across all demographic groups.
The gay rights revolution represents one of the most dramatic shifts in social attitudes in modern history. Despite homosexuality being biologically natural and occurring across cultures, it has historically faced severe persecution. Historical homophobia stemmed from multiple sources: religious prohibitions, evolutionary psychology (homosexuality doesn't directly produce offspring), and the human tendency to equate disgust with immorality. However, Enlightenment thinkers began questioning anti-gay laws, and recent decades have seen remarkable progress. By 2009, sixty-seven countries had decriminalized homosexuality, with the U.S. Supreme Court striking down remaining sodomy laws in 2003.
Our relationship with animals reveals a profound moral paradox. Most people believe animals feel pain and deserve protection, yet humans have historically treated animals with astonishing cruelty. Throughout history, animals were treated as mere automata. Aristotle placed them outside moral consideration, Descartes claimed they lacked consciousness, and early modern Europeans practiced vivisection and brutal factory farming without ethical qualms. The modern animal welfare movement gained momentum in the 1970s with Peter Singer's influential "Animal Liberation," which applied utilitarian ethics to animal suffering. Recent decades have seen significant progress: declining acceptance of blood sports, reduced hunting participation, humane treatment standards in entertainment, and growing consumer demand for humanely raised food.
第 9 章
Our Inner Demons and Better Angels
The historical decline of violence reveals two profound insights about human nature: our capacity for violence and our capacity to reduce it. History shows violence pervading human societies-from tribal warfare and infanticide to torture and various forms of killing-yet not a single category of violence has remained at a fixed rate throughout history. This contradiction helps resolve an ancient philosophical debate: humans are neither inherently peaceful nor irredeemably violent. Rather, human nature contains multiple faculties-motives that can impel us toward violence (predation, dominance, vengeance) and others that can lead us toward peace (compassion, fairness, self-control, reason).
Predatory violence-also called practical, instrumental, exploitative violence-is the simplest form of aggression. It involves no destructive motive like hate or anger, but merely taking the shortest path to something desired, with a living thing standing in the way. Self-serving biases-particularly "positive illusions" about one's abilities, power, and luck-can escalate violence. These delusions aren't merely psychological comfort but evolved bargaining tactics. By credibly exaggerating your strengths (by believing the exaggeration yourself), you gain advantages.
Contests for dominance represent a fundamentally different category of violence from predation. Though nothing tangible is at stake, they can be among the deadliest forms of human quarrel-from world wars fought over national preeminence to homicides sparked by "trivial altercations" like insults or jostling. The dark side of our communal feelings is a desire for our own group to dominate others. Henri Tajfel's famous experiments showed that even when assigned to arbitrary groups (like preferring Klee or Kandinsky paintings), people favored their own group members and would even penalize outgroup members rather than maximize benefits for all.
Sadism-the deliberate infliction of pain solely for enjoying another's suffering-follows a developmental trajectory where initial revulsion transforms into pleasure and even addiction. Baumeister explains this transformation through Richard Solomon's opponent-process theory. Like complementary colors, emotions come in opposing pairs. When one emotion (like fear) is repeatedly experienced, it weakens while its counterpart (reassurance) strengthens. With sadism, the initial revulsion to causing pain gradually weakens, while the reassuring counteremotion that follows grows stronger until it predominates, creating a positive experience.
While individuals have plenty of selfish motives for violence, the truly massive death tolls in history come from ideologies-belief systems that promise an infinite good that justifies any means. Ideological violence has driven humanity's worst atrocities: the Crusades, religious wars, the Holocaust, and the genocides of Stalin, Mao, and Pol Pot. People have numerous mechanisms to overcome their moral inhibitions when participating in atrocities. Euphemism is one powerful tool-reframing harmful actions with sanitized language like "pacification" instead of "bombing villages," "transfer of population" instead of "forced displacement," or "elimination of unreliable elements" instead of "imprisonment and execution."
Our capacity for sympathy extends beyond close relationships through reciprocal altruism, which makes us probe for potentially beneficial relationships with strangers. We're particularly likely to feel sympathy when we can confer large benefits at small personal costs to someone in need, or when common interests exist. Even toddlers help those in difficulty, and experiments show adults respond with sympathy to needy individuals regardless of social circle-whether fellow students, strangers, children, or even animals.
Self-control research shows it functions like a muscle that can be strengthened through exercise. Baumeister tested this by having participants undertake self-control regimens for weeks or months-tracking food intake, exercising regularly, managing money, using their non-preferred hand for tasks, or following speech rules like avoiding curse words and not beginning sentences with "I." After this training, participants showed greater resistance to ego depletion in lab tests and demonstrated improved self-control in daily life-smoking less, drinking less alcohol, eating less junk food, spending less money, watching less TV, studying more, and even washing dishes more promptly.
第 10 章
On Angels' Wings: The Future of Peace
This book originated as an answer to the question "What are you optimistic about?" but the author feels gratitude rather than optimism when surveying the historical decline of violence. While confident that practices like human sacrifice and chattel slavery won't return, he remains scientifically skeptical about predicting future violence levels. The declines documented throughout the book resulted from specific social, cultural, and material conditions-if these persist, violence will remain low or decrease further; if not, violence could resurge.
Understanding violence reduction requires examining what makes violence both tempting and difficult to abandon. The Pacifist's Dilemma (a renamed Prisoner's Dilemma) illustrates this perfectly: when faced with potential conflict, being aggressive is individually rational whether your opponent chooses peace or war. If they choose peace, aggression brings victory (10 points versus 5 for mutual peace); if they choose aggression, fighting back minimizes your losses (-50 versus -100 for pacifism).
A state monopolizing force to protect citizens from one another represents perhaps the most consistent violence-reducer in human history. By imposing costs on aggressors that exceed potential gains-say, penalties three times greater than the advantage of aggression over peace-the Leviathan flips the rational calculation, making peace more attractive than war. Beyond changing the arithmetic, a Leviathan (or Justitia, justice's goddess) serves as a disinterested third party whose penalties aren't inflated by participants' self-serving biases and who isn't a legitimate target for revenge.
The Enlightenment idea that exchanging benefits transforms zero-sum warfare into positive-sum mutual profit fundamentally changes the Pacifist's Dilemma by sweetening peaceful outcomes with mutual gains. While commerce doesn't eliminate the disaster of defeat, it removes the incentive for attack since both parties benefit from exchange. This pacifying effect depends partly on exogenous factors: each party specializing in producing what others want and infrastructure supporting exchange (transportation, finance, contract enforcement).
Tsutomu Yamaguchi, who survived both Hiroshima and Nagasaki atomic blasts, offered this prescription for nuclear peace: "The only people who should govern countries with nuclear weapons are mothers, those who are still breast-feeding their babies." His insight reflects the fundamental empirical pattern that violence is overwhelmingly committed by males. From boyhood play to violent crime, from war planning to revenge fantasies, males consistently show greater propensity for violence. Women have historically led pacifist movements disproportionately, and recent decades of unprecedented female influence coincide with wars between developed states becoming "unthinkable."
The expanding circle of sympathy transforms the psychological calculus of violence by intermingling our well-being with that of potential adversaries. While perfect fusion of all humanity's interests remains utopian, even small increases in valuing others' welfare can reduce aggression against them. Historical evidence links perspective-taking opportunities with increased sympathy. The 17th century's technological advances in publishing created a "Republic of Letters" and "Reading Revolution" that laid groundwork for the Humanitarian Revolution.
In his final reflection, Pinker acknowledges the reality behind his statistics: each data point represents real human suffering-stabbings, torture, rape, and murder on a scale of hundreds of millions. Yet humanity has found ways to reduce these horrors, allowing more people to live in peace and die naturally. For all our troubles, the decline of violence is an accomplishment to savor and an impetus to cherish the forces of civilization and enlightenment that made it possible.
