The trends have a few things in common. In each case they had to swim against powerful currents of human nature. These include the dehumanization and demonization of out-groups; men's sexual rapacity and their proprietary sentiments toward women; manifestations of parent-offspring conflict such as infanticide and corporal punishment; the moralization of sexual disgust in homophobia; and our meat hunger, thrill of the hunt, and boundaries of empathy based on kinship, reciprocity, and charisma.

As if biology didn't make things bad enough, the Abrahamic religions ratified some of our worst instincts with laws and beliefs that have encouraged violence for millennia: the demonization of infidels, the ownership of women, the sinfulness of children, the abomination of homosexuality, the dominion over animals and denial to them of souls. Asian cultures have plenty to be ashamed of too, particularly the mass disowning of daughters that encouraged a holocaust of baby girls. And then there is the entrenchment of norms: beating wives, smacking children, confining calves, and shocking rats were acceptable because everyone had always treated them as acceptable.

When I began my research for this chapter, I knew that the decades of the Long Peace and the New Peace were also decades of progress for racial minorities, women, children, gay people, and animals. But I had no idea that in every case, quantifiable measures of violence -- hate crimes and rape, wife-beating and child abuse, even the number of motion pictures in which animals were harmed -- would all point downward. How can we make sense of all the movements toward nonviolence of the past fifty years?

This conclusion, of course, is the moral vision of the Enlightenment and the strands of humanism and liberalism that have grown out of it. The Rights Revolutions are liberal revolutions. Each has been associated with liberal movements, and each is currently distributed along a gradient that runs, more or less, from Western Europe to the blue American states to the red American states to the democracies of Latin America and Asia and then to the more authoritarian countries, with Africa and most of the Islamic world pulling up the rear. In every case, the movements have left Western cultures with excesses of propriety and taboo that are deservedly ridiculed as political correctness. But the numbers show that the movements have reduced many causes of death and suffering and have made the culture increasingly intolerant of violence in any form.

Insofar as violence is immoral, the Rights Revolutions show that a moral way of life often requires a decisive rejection of instinct, culture, religion, and standard practice. In their place is an ethics that is inspired by empathy and reason and stated in the language of rights. We force ourselves into the shoes (or paws) of other sentient beings and consider their interests, starting with their interest in not being hurt or killed, and we ignore superficialities that may catch our eye such as race, ethnicity, gender, age, sexual orientation, and to some extent, species.

To hear the liberal punditry talk, one would think that the United States has been hurtling rightward for more than forty years, from Nixon to Reagan to Gingrich to the Bushes and now the angry white men in the Tea Party movement. Yet in every issue touched by the Rights Revolutions -- interracial marriage, the empowerment of women, the tolerance of homosexuality, the punishment of children, and the treatment of animals -- the attitudes of conservatives have followed the trajectory of liberals, with the result that today's conservatives are more liberal than yesterday's liberals. As the conservative historian George Nash points out, "In practice if not quite in theory American conservatism today stands well to the left of where it stood in 1980." (Maybe that's why the men are so angry.)

What caused the Rights Revolutions? As hard as it was to establish the causes of the Long Peace, New Peace, and 1990s crime decline, it's harder still to pinpoint an exogenous factor that would explain why the Rights Revolutions bunched up when they did. But we can consider the standard candidates.

Democratic government obviously played a role. The Rights Revolutions took place in democracies, which are constituted as social contracts among individuals designed to reduce violence among them; as such they contain the seeds of expansion to groups that originally had been overlooked. But the timing remains a puzzle, because democracy is not an entirely exogenous variable. It was the machinery of democracy itself that was at issue during the American civil rights movement, when the political disenfranchisement of blacks was remedied. In the other revolutions too, new groups were invited or argued their way into full partnership in the social contract. Only then could the government be empowered to police violence (or cease its own violence) against members of the affected groups.

The postwar years saw an expansion of prosperity, but prosperity has such a diffuse influence on a society that it offers little insight into the revolutions' immediate triggers. Money can buy education, police, social science, social services, media penetration, a professional workforce with more women, and better care of children and animals. It's hard to identify which of these made a difference, and even if we could, it would raise the question of why society chose to distribute its surplus among these various goods in such a way as to reduce harm to vulnerable populations. And though I know of no rigorous statistical analysis, I can discern no correlations between the timing of the various upswings in the consideration of rights from the 1960s to the 2000s and the economic booms and recessions of those decades.

During the Rights Revolutions, networks of reciprocity and trade had expanded with the shift from an economy based on stuff to one based on information. Women were less enslaved by domestic chores, and institutions sought talent from a wide pool of human capital rather than just from the local labor supply or old boys' club. As women and members of minority groups were drawn into the wheelings and dealings of government and commerce, they ensured that their interests were factored into their workings. We have seen some evidence for this mechanism: countries with more women in government and the professions have less domestic violence against women, and people who know gay people personally are less likely to disapprove of homosexuality. But as with democracy, the inclusiveness of institutions is not a completely exogenous process. The hidden hand of an information economy may have made institutions more receptive to women, minorities, and gays, but it still took government muscle in the form of antidiscrimination laws to integrate them fully. And in the case of children and animals, there was no market for reciprocal exchanges at all: the beneficence went in one direction.

I've mentioned the connection before. The Humanitarian Revolution came out of the Republic of Letters, and the Long Peace and New Peace were children of the Global Village. And remember what went wrong in the Islamic world: it may have been a rejection of the printing press and a resistance to the importation of books and the ideas they contain.

If I were to put my money on the single most important exogenous cause of the Rights Revolutions, it would be the technologies that made ideas and people increasingly mobile. The decades of the Rights Revolutions were the decades of the electronics revolutions: television, transistor radios, cable, satellite, long-distance telephones, photocopiers, fax machines, the Internet, cell phones, text messaging, Web video. They were the decades of the interstate highway, high-speed rail, and the jet airplane. They were the decades of the unprecedented growth in higher education and in the endless frontier of scientific research. Less well known is that they were also the decades of an explosion in book publishing. From 1960 to 2000, the annual number of books published in the United States increased almost fivefold. 305

Another causal pathway is an increase in invitations to adopt the viewpoints of people unlike oneself. The Humanitarian Revolution had its Clarissa, Pamela, and Julie, its Uncle Tom's Cabin and Oliver Twist, its eyewitness reports of people being broken, burned, or flogged. During the electronic age, these empathy technologies were even more pervasive and engaging. African Americans and gay people appeared as entertainers on variety shows, then as guests on talk shows and as sympathetic characters on sitcoms and dramas. Their struggles were depicted in real-time footage of fire hoses and police dogs, and in bestselling books and plays like Travels with Charley, A Raisin in the Sun, and To Kill a Mockingbird. Telegenic feminists made their case on talk shows, and their views came out of the mouths of characters in soap operas and sitcoms.

Why should the spread of ideas and people result in reforms that lower violence? There are several pathways. The most obvious is a debunking of ignorance and superstition. A connected and educated populace, at least in aggregate and over the long run, is bound to be disabused of poisonous beliefs, such as that members of other races and ethnicities are innately avaricious or perfidious; that economic and military misfortunes are caused by the treachery of ethnic minorities; that women don't mind being raped; that children must be beaten to be socialized; that people choose to be homosexual as part of a morally degenerate lifestyle; that animals are incapable of feeling pain. The recent debunking of beliefs that invite or tolerate violence call to mind Voltaire's quip that those who can make you believe absurdities can make you commit atrocities.

And as we will see in chapter 9, it is not just the virtual reality experience of seeing the world through another person's eyes that expands empathy and concern. It is also an intellectual agility -- literally a kind of intelligence -- which encourages one to step outside the parochial constraints of one's birth and station, to consider hypothetical worlds, and to reflect back on the habits, impulses, and institutions that govern one's beliefs and values. This reflective mindset may be a product of enhanced education, and it may also be a product of electronic media. As Paul Simon marveled:

The way we look to us all.

These are the days of miracle and wonder,

This is the long distance call,

There is a third way that a flow of information can fertilize moral growth. Scholars who have puzzled over the trajectory of material progress in different parts of the world, such as the economist Thomas Sowell in his Culture trilogy and the physiologist Jared Diamond in Guns, Germs, and Steel, have concluded that the key to material success is being situated in a large catchment area of innovations. No one is smart enough to invent anything in isolation that anyone else would want to use. Successful innovators not only stand on the shoulders of giants; they engage in massive intellectual property theft, skimming ideas from a vast watershed of tributaries flowing their way. The civilizations of Europe and western Asia conquered the world because their migration and shipping routes allowed traders and conquerors to leave behind inventions that had originated anywhere in the vast Eurasian landmass: cereal crops and alphabetic writing from the Middle East, gunpowder and paper from China, domesticated horses from Ukraine, oceangoing navigation from Portugal, and much else. There is a reason that the literal meaning of cosmopolitan is "citizen of the world," and the literal meaning of insular is "of an island." Societies that are marooned on islands or in impassable highlands tend to be technologically backward. And morally backward too. We have seen that cultures of honor, whose overriding ethic is tribal loyalty and blood revenge, can survive in mountainous regions long after their lowland neighbors have undergone a civilizing process.

The way the camera follows us in slo-mo

What's true of technological progress may also be true of moral progress. Individuals or civilizations that are situated in a vast informational catchment area can compile a moral know-how that is more sustainable and expandable than even the most righteous prophet could devise in isolation. Let me illustrate this point with a potted history of the Rights Revolutions.

In his 1963 essay "Pilgrimage to Nonviolence," Martin Luther King recounted the intellectual threads that he wove into his political philosophy. As a graduate student in theology in the late 1940s and early 1950s, he was, of course, conversant with the Bible and orthodox theology. But he also read renegade theologians such as Walter Rauschenbusch, who criticized the historical accuracy of the Bible and the dogma that Jesus died for people's sins.

King then embarked on "a serious study of the social and ethical theories of the great philosophers, from Plato and Aristotle down to Rousseau, Hobbes, Bentham, Mill, and Locke. All of these masters stimulated my thinking -- such as it was -- and, while finding things to question in each of them, I nevertheless learned a great deal from their study." He carefully read (and rejected) Nietzsche and Marx, inoculating himself against the autocratic and communist ideologies that would be so seductive to other liberation movements. He also rejected the "anti-rationalism of the continental theologian Karl Barth," while admiring Reinhold Niebuhr's "extraordinary insight into human nature, especially the behavior of nations and social groups… These elements in Niebuhr's thinking helped me to recognize the illusions of a superficial optimism concerning human nature and the dangers of a false idealism."

King's thinking was irrevocably changed one day when he traveled to Philadelphia to hear a lecture by Mordecai Johnson, the president of Howard University. Johnson had recently returned from a trip to India and spoke about Mohandas Gandhi, whose influence had recently culminated in national independence. "His message was so profound and electrifying," King wrote, "that I left the meeting and bought a half-a-dozen books on Gandhi's life and works."

King immediately appreciated that Gandhi's theory of nonviolent resistance was not a moralistic affirmation of love, as nonviolence had been in the teachings of Jesus. Instead it was a set of hardheaded tactics to prevail over an adversary by outwitting him rather than trying to annihilate him. A taboo on violence, King inferred, prevents a movement from being corrupted by thugs and firebrands who are drawn to adventure and mayhem. It preserves morale and focus among followers when the movement suffers early defeats. By removing any pretext for legitimate retaliation by the enemy, it stays on the positive side of the moral ledger in the eyes of third parties, while luring the enemy onto the negative side. For the same reason, it divides the enemy, paring away supporters who find it increasingly uncomfortable to identify themselves with one-sided violence. All the while it can press its agenda by making a nuisance of itself with sit-ins, strikes, and demonstrations. The tactic obviously won't work with all enemies, but it can work with some.

King's historic speech to the March on Washington in 1963 was an ingenious recombination of the intellectual components he had collected during his peripatetic pilgrimage: imagery and language from the Hebrew prophets, the valorization of suffering from Christianity, the ideal of individual rights from the European Enlightenment, cadences and rhetorical tropes from the African American church, and a strategic plan from an Indian who had been steeped in Jain, Hindu, and British culture.

It is not too lazy to say that the rest is history. The moral contrivance assembled by King was thrown back into the idea pool, there to be adapted by the entrepreneurs of the other rights movements. They consciously appropriated its name, its moral rationale, and significantly, many of its tactics.

By the standards of history, a striking feature of the late-20th-century Rights Revolutions is how little violence they employed or even provoked. King himself was a martyr of the civil rights movement, as were the handful of victims of segregationist terrorism. But the urban riots that we associate with the 1960s were not a part of the civil rights movement and erupted after most of its milestones were in place. The other revolutions had hardly any violence at all: there was the nonlethal Stonewall riot, some terrorism from the fringes of the animal rights movement, and that's about it. Their entrepreneurs wrote books, gave speeches, held marches, lobbied legislators, and gathered signatures for plebiscites. They had only to nudge a populace that had become receptive to an ethic based on the rights of individuals and were increasingly repelled by violence in any form. Compare this record to that of earlier movements which ended despotism, slavery, and colonial empires only after bloodbaths that killed 以历史的标准来看,20世纪后期权利运动最显著的特征就是它所使用和所引起的暴力都非常之少.金自己成为民权运动的烈士,是种族隔离分子恐怖行动的少数受害人之一.我们谈到的20世纪60年代美国城市发生的暴动事件都与民权运动无关,它们是在民权运动已经取得历史性进展之后的事情.其他社会革命的暴力成分非常有限:(同性恋夜总会的)"石墙骚乱"没有人员伤亡,动物权利运动中有些极端分子采用了恐怖手段,仅此而已.后期权利运动的推动者们出版书籍,发表演讲,组织游行,游说议员,为公投收集签名.公众早已接受以个人权利为基础的道德准则,而且越来越排斥任何形式的暴力,权利运动所需要的只剩下发动公众.相比之下,推翻专制政治、结束奴隶制和殖民统治的早期权利运动,无一不经过死伤几十万甚至上百万的血腥战斗.