Amid the ashes of World War II, with the stench of industrial-scale genocide in their nostrils, the nations of the world pledged to do better. They signed onto the Universal Declaration of Human Rights. For the rest of the 20th century, human rights blossomed.
How can it be that, two decades into the new century, religion has become the banner under which indiscriminate slaughter, oppression, and petty cruelty is committed? How can a carnival of terror call itself a state and attract teens from the West?
How can India, the world's largest democracy, elect a Hindu nationalist alleged to have blood on his hands? How can a bare-chested buffoon rally millions of Russians to support theocratic fascism?
How can the Republican party, the party of Lincoln and Eisenhower, become so reactionary that its candidates repudiate science and a majority of its members want to establish Christianity as America's state religion?
These are not rhetorical questions. To salvage clarity from horror, we have to go way back to the roots of our predominant religion. In 1 Samuel 15, God tells Saul to go out and annihilate a neighboring city. The Lord's marching orders are specific: "Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass."
His army does just that, but Saul, in a moment of mercy, lets the Amelek king, Agag, off the hook. Not good enough for God. His prophet Samuel passes the word: the Big Guy is displeased. Saul still feels that the time for peace has come. So, Samuel does the Lord's work: he hacks Agag to bits.
The message is simple: Whatever the Lord orders is right. No need to trouble your conscience, Father knows best. This kind of religious primitivism licenses the horrors of ISIS, Boko Haram, and their bloody ilk. But why, even now, does it work?
The answers lie in human nature, whose caverns we have only recently begun to illuminate by the light of science. Humans are endowed by evolution with a moral sense. It manifests in universal feelings that are encoded variously in cultures. Among the moral emotions are empathy, compassion, fairness, guilt, disgust, outrage, humiliation, purity, divinity, and a passion for punishing wrongdoers.
Unfortunately, evolution itself is amoral, so it has built a faulty system. Chief among its faults is that benevolent feelings evolved to apply only to members of our own group. Anthropologist Robin Dunbar estimates that our circle of amity extended to bands of about 150 during the long hunter-gatherer phase. By the time of the Bible, it had grown uneasily to intertribal leagues, and even alliances, but woe betide anyone beyond the pale.
Christians rightly point to the teachings of Jesus as a landmark in moral universalism. Scholars debate just how widely they were intended to apply, but there's no reason to quibble over the modern interpretation. The same can be said for Islam, the other great religion with universal aspirations.
But interpretation is everything: throughout history, great religions have been wielded to opposite effect. The moral instincts, hitched to a toxic idealism, allow for unbounded cruelty and slaughter. Here's why: it is all too easy for any of us to banish a class of persons from our circle of moral benevolence.
Feel envious of the Jews? Just start a rumor that they use Christian babies' blood in their rituals, and you get centuries of pogroms leading up to the Holocaust. Angry at a woman? Stir up stories of witchcraft, and you get centuries of burnings. Need help but don't want to pay for it? Concoct a story that Africans are the descendants of accursed Ham, and you are licensed to enslave them. Some pesky people living on land that you covet? Not a problem -- just invade and forcibly convert them. It's a win-win!
The moral mechanisms of these barbarities are not hard to grasp: they draw on those latent feelings of disgust, humiliation, and outrage and connect them with a transcendent ideal: God's will.
Fortunately, we have a way to rise above this tangle of instincts. Our ability to use language, and especially our ability to read and write so as to widely share experiences and ideas, has gradually allowed us to understand that, as much as we may differ in appearance and culture, we share in the universals of humanity. "If you prick us," Shakespeare wrote, "do we not bleed?"
Uncle Tom's Cabin helped white Americans understand that slavery was wrong; the novels of Dickens helped the British realize that the poor deserved compassion and decent treatment, and, yes, religious texts -- the Talmud, the Bible, the Quran and others -- inspired acts of genuine compassion.
Our remaining challenge is to instill the value of universal human rights universally. Though some believe that this could be done by abolishing religion, I disagree. For one, other toxic ideals exist. Race, nationalism, ethnicity, radical feminism, even the free market can trigger a disastrous moral cascade that results in identity politics, the exclusion of outsiders from moral consideration.
For another, there is a clear dividing line in religions: Old Time Religion, the authoritarian version that plays on dark moral emotions, is the problem. It's remarkably similar across all "brand names." Watch the behavior and you find radical Islamists, Buddhists, Jews, Hindus, and Christians all claim holy justification for hateful and often violent acts toward the Other. But we cannot forget that most religionists are not like this, and that the most enlightened among them embrace all of humanity in their circle of benevolence.
Still, to go the next step, we must make the science of human nature at least as widely known and acculturated as the science of genetics has become. To school yourself, you cannot do better than to read Steven Pinker's book The Blank Slate. Self-knowledge is power for good.