Harari traces three revolutions that shaped us: the Cognitive Revolution that gave us shared stories, the Agricultural Revolution that tied us to land, and the Scientific Revolution that gave us power over nature.
His central claim is that humans cooperate at scale because we believe in shared fictions — money, nations, companies, laws — that exist only in our collective imagination.
Key ideas
1
Shared fictions
Large-scale cooperation depends on stories we all believe — from gods to limited liability companies.
2
Agriculture’s trap
Farming fed more people but often made individual lives harder, more anxious and less varied.
3
Money as trust
Money is the most universal system of mutual trust ever devised.
4
Empires unify
For all their violence, empires spread shared languages, laws and cultures.
5
Progress and happiness
More power has not reliably made us happier — a question science is only starting to ask.
Chapter breakdown
4 chapters · 21 min
Summary by chapter
Sapiens in 20 chapters, in our own words.
Chapter 1
An Animal of No Significance
Harari opens his story at the widest possible angle. Physics begins with the Big Bang some 13.5 billion years ago, chemistry and biology follow, and only very late in the tale does a genus of apes called Homo appear in East Africa, about 2.5 million years ago. The point he wants to plant early is humbling: humans are animals, and for most of our existence we were not particularly important ones. Several human species once walked the earth at the same time. Neanderthals lived in Europe and western Asia, Homo erectus survived in eastern Asia for close to two million years, Homo soloensis lived on Java, Homo denisova in Siberia, and on the Indonesian island of Flores lived Homo floresiensis, tiny people about a meter tall and no heavier than 25 kilograms. As recently as 100,000 years ago, at least six human species shared the planet.
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The truth is that from about 2 million years ago until around 10,000 years ago, the world was home, at one and the same time, to several human species.
Yuval Noah Harari
What made these early humans different was a big and costly brain. Ours makes up only 2 to 3 percent of body weight yet burns about a quarter of the body’s energy at rest, compared with around 8 percent for other apes. Feeding that organ took a lot of time, and for two million years humans sat somewhere in the middle of the food chain. They gathered plants, caught small animals, scavenged what larger hunters left behind, and were hunted in turn. Harari argues that our leap to the top came so late and so fast that neither the ecosystem nor we had time to adjust. Lions and sharks rose over millions of years; we rose in a blink, and he suggests our anxious, destructive streak may be the legacy of a creature that was an underdog until very recently.
Fire was one important step. Some human species used it now and then perhaps 800,000 years ago, and by about 300,000 years ago its daily use was common. Cooking made new foods edible, killed germs and cut the time spent chewing and digesting. Still, 100,000 years ago Homo sapiens was just one human species living in a corner of Africa, with nothing to suggest a grand future.
So what happened to the others? Harari lays out two competing explanations. The Interbreeding Theory holds that Sapiens mixed with the populations it met as it spread out of Africa from around 70,000 years ago. The Replacement Theory holds that Sapiens pushed them aside through competition or violence. Genetic evidence points to something in between: people of European and Middle Eastern descent carry roughly 1 to 4 percent Neanderthal DNA, and some populations carry Denisovan DNA, yet the contribution is small. Harari finds it hard to believe that the swift disappearance of our cousins after Sapiens arrived was a coincidence, and he invites readers to imagine a world in which another human species had survived. Being alone, he suggests, may have made ideas of human uniqueness easier to hold.
Chapter 2
The Tree of Knowledge
Around 70,000 years ago, something changed inside the heads of Homo sapiens. Harari calls it the Cognitive Revolution, and he treats it as the true starting point of history. After this time, Sapiens began making art, jewelry, oil lamps, and needles for sewing warm clothes, and bands of them spread across the world. The key was a new kind of language. Many animals can signal danger, and a chimpanzee can warn its group about a lion. Sapiens could do something stranger: talk about things that do not exist at all. Spirits, tribal gods, nations, companies and human rights all live only in our shared imagination.
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You could never convince a monkey to give you a banana by promising him limitless bananas after death in monkey heaven.
Yuval Noah Harari
Why does fiction matter so much? Because it lets strangers cooperate. Groups held together by gossip and personal ties tend to top out at about 150 people, a figure known as Dunbar’s number. Chimpanzees rarely keep stable groups above about 50. But two people who have never met can work together if they believe in the same god, the same law or the same money. Harari’s favorite example is Peugeot, the French carmaker. It is not its factories, its workers or its cars. It is a legal fiction that lawyers, shareholders and governments agree to treat as real. Yet it can own property, hire thousands of people and be sued in court.
Harari is careful to say these shared stories are not simply lies. He separates three kinds of reality. Objective things, like gravity, exist whatever we believe. Subjective things, like a headache, exist inside one mind. Intersubjective things, like money, nations and corporations, exist in the web of communication between many minds. A dollar bill is paper, but because billions of people trust it, it moves mountains. When belief fades, such orders can collapse, as happened to the Soviet Union once faith in communism dried up.
The deepest consequence is speed. Ants and bees cooperate in huge numbers, but their behavior is fixed by genes; a hive cannot suddenly reorganize its politics. Humans can rewrite their social order by changing the story, as the French Revolution did when it swapped the divine right of kings for the sovereignty of the people. From this point on, cultural change outpaced genetic change, and groups of nearly identical Sapiens could live in wildly different ways, from arctic tundra to tropical forest. Harari’s striking conclusion is that this capacity for flexible, large-scale cooperation, not tools or big brains alone, is what let Sapiens outcompete Neanderthals and every other rival. Biology set the limits, but from here on history, not evolution, would drive the plot.
Chapter 3
A Day in the Life of Adam and Eve
To understand ourselves, Harari argues, we need to understand foragers. For most of the time since the Cognitive Revolution, until farming began roughly 12,000 years ago, every human lived by hunting and gathering, and our bodies and minds were shaped by that life. He is wary of the phrase Stone Age, because most tools were made of wood, bone and other materials that rotted away; stone simply survives better. Our knowledge comes from scattered artifacts, from studying modern foraging peoples, and from features common to all known foraging societies. Each source has limits, and Harari warns against both romantic and dismissive pictures.
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But at the individual level, ancient foragers were the most knowledgeable and skilful people in history.
Yuval Noah Harari
With that caution in place, a surprising portrait emerges. Foragers typically ate dozens or even hundreds of different plants and animals, which made their diet varied and protected them from famine when one food failed. They carried detailed mental maps of their territories and knew the habits of animals and the uses of countless plants. Studies of some foraging peoples suggest they spent around 35 to 45 hours a week getting food, leaving room for rest and socializing. Most bands were small, several dozen people who knew each other intimately, and they moved often, owning only what they could carry. Many held animist beliefs, seeing animals, plants and places as beings with their own will, to be negotiated with rather than ruled.
Was this a peaceful Eden or a brutal free-for-all? Harari refuses to pick a side, because the evidence is thin and mixed. Some sites, such as Jebel Sahaba in Sudan, contain many skeletons marked by violence, while others show little sign of it. Modern foraging peoples range from fairly calm to frequently at war. The lesson he draws is that there was no single natural human way of life. Foragers adapted their customs, beliefs and politics to their surroundings, and they differed as much as later societies would.
The same humility applies to happiness. Skeletons suggest early farmers were shorter, had worse teeth and suffered more malnutrition than foragers, so in some ways foragers were healthier. But they also faced predators, accidents, hostile neighbors and high infant mortality, with no medicine or safety net. Harari adds that contentment depends heavily on expectations, so a life that looks hard to us may have felt fine to those living it. His conclusion is modest: we cannot know whether foragers were happier than we are, and that uncertainty should make us skeptical of easy stories about progress.
Chapter 4
The Flood
Long before cities or factories, Sapiens was already reshaping the planet. Harari’s chapter on the first human migrations reads like an ecological crime report. When humans reached Australia around 45,000 years ago, the great majority of its large animals vanished within a few thousand years. Among them were giant kangaroos, marsupial lions and the diprotodon, a wombat-like beast roughly the size of a modern truck. When humans crossed into the Americas about 16,000 years ago, mammoths, mastodons, saber-toothed cats, giant ground sloths, and native horses and camels disappeared within roughly two thousand years. Islands told the same story. Madagascar lost its elephant birds and giant lemurs, and New Zealand lost its moas.
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Don’t believe tree-huggers who claim that our ancestors lived in harmony with nature.
Yuval Noah Harari
Climate change is often blamed, and Harari grants it some role. But many of these species had survived earlier ice ages and warm spells, and their extinctions line up far better with the arrival of humans than with shifts in climate. Large animals were especially vulnerable. They bred slowly, carried young for a long time, and had never met a predator like Sapiens, so they had no instinctive fear of it. Humans did not always need to hunt a species to its end. Burning landscapes, disrupting food chains and competing for the same food could be enough to push big animals over the edge.
The chapter’s title refers to this wave of destruction that rolled across continent after continent. The flood did not stop with foraging. Farming raised the stakes by clearing forests, draining wetlands, planting single crops over vast areas and breeding domesticated animals that crowded out wild ones. Where early hunters had already killed off many large species, agriculture went on to erase the habitats of countless smaller ones.
Harari’s purpose here is to overturn a comforting myth. We like to think of ancient people as living in harmony with nature, with environmental ruin as a modern invention of industry or capitalism. The evidence suggests otherwise: even small bands with simple tools were among the most effective destroyers the natural world has known. He compares the impact to the asteroid that ended the dinosaurs, with the difference that this catastrophe came from a single species. Today’s biodiversity crisis, in his telling, is not a sudden break with the past but the speeding up of a pattern as old as our wanderings. That framing makes the chapter both sobering and oddly useful, because it asks readers to see current environmental debates against a very long record.
Chapter 5
History’s Biggest Fraud
Farming is usually celebrated as the moment humanity stepped onto the road to civilization. Harari calls it history’s biggest fraud. Beginning around 10,000 BCE, people in several regions started devoting their days to tending a few plants and animals, and for the average person, he argues, life got worse. Farmers worked longer and harder than foragers, clearing fields, planting, weeding, harvesting and grinding grain. Their diet shrank to a handful of staples like wheat or rice, bringing vitamin deficiencies and famine whenever harvests failed. Crowded permanent villages, full of waste and close to animals, became breeding grounds for disease. Skeletons show farmers were generally shorter and less healthy than the foragers who came before.
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We did not domesticate wheat. It domesticated us.
Yuval Noah Harari
Harari’s most memorable twist is to ask who domesticated whom. Wheat began as a wild grass in a small part of the Middle East and became one of the most widespread plants on earth. It managed this by getting Sapiens to clear forests, dig irrigation channels, chase away pests and organize their whole lives around its needs. From wheat’s point of view, the arrangement was a triumph.
If farming was such a bad deal, why did it spread? Because evolutionary success is measured in numbers, not happiness. Farming fed far more mouths per acre, and the human population grew from perhaps 5 to 8 million foragers to hundreds of millions of farmers. A village of farmers could overwhelm a small band of foragers even if each farmer was weaker and more miserable. The switch also happened slowly, through small choices that each seemed sensible. A group planted a little wheat to supplement foraging, the food supply grew, more children survived, and soon there were too many people to go back. Harari calls this the luxury trap and compares it to modern gadgets like email and smartphones, which promised to save time and ended up making life busier.
Farming also changed the human mind. Foragers lived mostly in the present, but farmers had to worry about next season’s rain, pests and thieves, and they stored surplus against lean years. That surplus rarely went to the people who grew it. It fed kings, priests and soldiers, and it pinned peasants to plots of land where they could be taxed and drafted. Harari’s larger lesson is one that echoes through the rest of the book: changes that make a species more powerful do not necessarily make its individual members better off, and once such changes take hold they are very hard to reverse.
Chapter 6
Building Pyramids
How did millions of strangers come to cooperate in building pyramids, cathedrals and empires? Not through instinct, Harari argues, and not mainly through force, but through imagined orders. The laborers who hauled stone in ancient Egypt shared beliefs about gods, pharaohs and the afterlife, and those shared beliefs made it possible to organize labor and resources on a staggering scale. Imagined orders such as religion, law, money and nationhood are the scaffolding of every large society, and they work as long as enough people believe in them.
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In contrast, an imagined order is always in danger of collapse, because it depends upon myths, and myths vanish once people stop believing in them.
Yuval Noah Harari
The obvious question is why these fragile stories are so stable. Harari identifies several reasons. First, imagined orders are built into the physical world. A medieval peasant who lived beside a towering cathedral saw the reality of Christianity every day. Modern cities are organized around shopping districts and business centers, quietly embodying the logic of the market. Second, these orders shape our desires. People do not just obey them from the outside; they want what the order teaches them to want. A medieval nobleman longed to be a brave knight, and a modern teenager longs for the newest phone, and both feel their wishes are their own. Harari points to the dream of an exotic vacation, which feels personal but grows out of a blend of romanticism and consumerism. Medieval peasants, shaped by a different order, had no such dream.
Third, imagined orders are intersubjective, which makes them hard for any one person to change. If you stop believing in money or national borders, nothing happens, because millions of others still believe. Changing such an order requires convincing huge numbers of people at once, usually through some rival story backed by its own organizations.
Finally, Harari notes a clever trick all imagined orders use: they deny being imagined. The Christian order claimed to rest on God’s eternal will, the liberal order claims to rest on natural human rights, and capitalism points to supposedly objective laws of economics. By presenting themselves as facts of nature, these systems make alternatives hard to picture. Harari does not treat this as a reason for cynicism. Without shared fictions there would be no cities, art or science. But he wants readers to see that the social world is built by humans, which means it can be rebuilt, even if doing so is enormously difficult and usually means replacing one imagined order with another rather than escaping imagined orders altogether.
Chapter 7
Memory Overload
The human brain evolved to hold the knowledge a forager needs: the local terrain, the seasons, which plants heal and which kill, and who in the band can be trusted. That is a lot, but it has limits. When farming gave rise to kingdoms, rulers suddenly needed to track the taxes owed by thousands of peasants, the grain in every storehouse, who owned which field, who owed whom, and how to pay and feed soldiers, priests and officials. No memory could manage this. Harari calls the result a genuine crisis: without a way to store and retrieve information outside the head, large states simply could not function.
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The most important impact of script on human history is precisely this: it has gradually changed the way humans think and view the world.
Yuval Noah Harari
The solution came first in Mesopotamia. Between roughly 3500 and 3000 BCE, the Sumerians developed a system of signs pressed into clay tablets. At first it recorded only numbers and a limited set of objects, such as a sign for a measure of grain or a sheep beside a tally. Harari calls this a partial script: good for accounts, useless for love poems or legal arguments. It is a crucial point in the chapter that the first writers were not poets or prophets but accountants. The earliest texts are dull lists of taxes paid, goods received and debts owed.
Over time, Sumerian scribes found a way to stretch their signs. They began using symbols for their sound as well as their meaning, a rebus-like trick that let them spell out names, grammar and abstract ideas. Between about 3000 and 2500 BCE this grew into cuneiform, a full script able to record anything that could be spoken. Kings used it for decrees and chronicles, and it eventually preserved works like the Epic of Gilgamesh. Other civilizations followed similar paths. Egyptian hieroglyphs mixed pictures and sounds, Chinese writing relied on many characters, and the Phoenicians created an alphabet of just a few dozen signs that the Greeks later refined by adding vowels.
Writing did more than store data; it changed how people thought. Information no longer had to be arranged to suit memory, through rhyme or story. It could be sorted into lists, categories and catalogs, the logic of the archive and the bureaucracy. This gave enormous power to the small class of scribes and officials who could read and write, and it let knowledge build up across generations. Harari presents writing as a quiet revolution that freed humans from the limits of biological memory and made complex states and, much later, science possible.
Chapter 8
There is No Justice in History
Nearly every large society since farming has divided people into ranks: free and enslaved, noble and commoner, one caste above another, men above women, one race above another. Harari’s central claim is that these hierarchies do not reflect natural differences. They are imagined orders, and like all imagined orders they insist that they are natural, divine or biological. The traditional Hindu caste system, for example, justified itself with a myth in which different castes came from different parts of a god’s body, making inequality look like part of the cosmos rather than a human choice.
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Culture tends to argue that it forbids only that which is unnatural. But from a biological perspective, nothing is unnatural.
Yuval Noah Harari
How does an arbitrary hierarchy last for centuries? Harari describes a vicious circle, and his main example is race in the Americas. It starts with a historical accident: Europeans conquering the Americas needed labor and turned to enslaved Africans for reasons that had to do with circumstance, not character. A story then grows up to explain the arrangement, claiming that Africans were suited to servitude. That story becomes law and custom. Enslaved people and their descendants are barred from education, wealth and political power. Those barriers produce real gaps in literacy and income, and the gaps are then pointed to as proof that the story was true all along. Even after slavery ended, segregation, voting restrictions and economic exclusion kept the circle turning, and its effects outlasted the formal ideology by generations.
Gender follows a similar pattern, and Harari admits it is especially puzzling because male dominance appears in so many cultures. He finds no convincing biological explanation. What he does see is the same mechanism: once men held most positions of power, they wrote laws and built religions and schools that kept women out, then cited women’s absence as evidence that they did not belong.
What makes these systems so durable is that they live inside people as well as institutions. Children are raised to see the hierarchy as normal, and those at the bottom often absorb the story of their own inferiority, which makes resistance harder. Changing minds is not enough to break the circle, because the material gaps it created remain. Harari’s title carries his sober message: history does not bend toward fairness on its own. Injustice persists mainly through the stories cultures tell and the structures those stories build, and ending it requires seeing those stories for the fictions they are and deliberately rebuilding what grew from them.
Chapter 9
The Arrow of History
Step back far enough, Harari suggests, and history has a direction. Around 10,000 BCE the world held thousands of separate human groups, each with its own language, gods and customs, many barely aware of one another. Today almost all of humanity lives inside one interconnected civilization. Distinct cultures still exist, but they have merged, borrowed and blended until events in one region ripple through all the others. The arrow points from many small worlds toward one large one.
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From such a vantage point it becomes crystal clear that history is moving relentlessly towards unity.
Yuval Noah Harari
Harari is careful not to turn this into a story of progress. The movement has not been smooth; empires have fallen and regions have splintered for long stretches. It has also been paid for in conquest and cultural loss, with languages and ways of life destroyed along the way. He does not claim the arrow has a purpose or a happy destination. He only claims it is there, rejecting both the view that history simply repeats in cycles and the view that it is meaningless noise.
What drove this unification? Harari names three universal orders, each of which imagined all of humanity as a potential community rather than dividing the world into us and them. The first is economic: money, which lets anyone trade with anyone. The second is political: empire, which gathers many peoples under one rule. The third is religious: universal faiths such as Buddhism, Christianity and Islam, which claim to speak to every human being. The Roman Empire bound the Mediterranean into a shared culture that outlived Rome’s political collapse. Islam linked lands stretching from Spain to Indonesia. Even the Mongol Empire, for all its brutality, opened routes between East and West.
Of the three, Harari singles out money as the most open-minded. People who share no language, religion or government can still agree on the value of a coin. Money rests on two principles: it can be converted into almost anything else, and everyone trusts that everyone else trusts it. That combination lets strangers who have every reason to distrust each other work together. The next three chapters take each universal order in turn, beginning with money, and together they explain how thousands of isolated bands became the single global society we live in today, with all the opportunities and shared risks that come with it.
Chapter 10
The Scent of Money
Money, Harari insists, is not coins or banknotes. It is anything people will systematically use to represent the value of other things so they can exchange goods and services. Its great achievement is to fix the weakness of barter. A shoemaker who wants apples must find an apple grower who happens to want shoes at that moment, and as the number of goods grows, direct swaps become hopeless. Money turns every product into a common measure, letting the shoemaker sell to anyone and buy from anyone.
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Trust is the raw material from which all types of money are minted.
Yuval Noah Harari
History has seen many kinds of money. The earliest known was barley money in Sumer around 3000 BCE, measured in standard units and used to pay workers and settle debts. Shells, cattle, salt and cloth have all served too. Precious metals eventually won out in many places because they were durable, portable, easy to divide and widely desired. Yet Harari stresses that gold’s value rests on belief even more than barley’s does. Barley can at least feed you; gold is fairly useless compared with iron or wheat. People prized it because they trusted that others would prize it, and that shared trust is the whole secret.
This is why he calls money the most universal and efficient system of mutual trust ever devised. A Christian and a Muslim who might disagree about everything else will accept the same coin. Money does not care about religion, gender, race, age or sexual orientation. It also stores value across time and space: a farmer can sell his harvest, keep the coins for years and spend them far away on something entirely different. That flexibility made specialization and long-distance trade possible, since a craftsman could devote himself to one skill and rely on money to buy everything else.
Harari does not treat money as purely benign. Because it is abstract, money can represent debts and promises of future wealth, which is powerful but fragile. When trust collapses, as in episodes of runaway inflation, money can become worthless overnight, revealing the fiction underneath. Governments and banks work hard to keep that trust intact. Harari’s picture is double-edged. Money has united humankind into one economic sphere more thoroughly than any empire or faith, while also creating new forms of dependence and inequality.
Chapter 11
Imperial Visions
Few words carry as much baggage today as empire. Harari asks readers to set their reflexive disapproval aside long enough to look at the record. He defines an empire by two features: it rules over many distinct peoples, each with its own identity and territory, and it has flexible borders and a potentially endless appetite for more. By that definition, empires have been the world’s most common political form for the last 2,500 years, and most humans in that time have lived under one.
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To colour all empires black and to disavow all imperial legacies is to reject most of human culture.
Yuval Noah Harari
Empires were typically built by conquest and maintained by force and exploitation. Harari does not deny any of this. His argument is that they also played a huge role in merging many small cultures into fewer large ones. Imperial elites often came to believe sincerely in a civilizing mission, convinced they were bringing law, order and culture to others. And imperial culture was rarely pure. Rome absorbed Greek culture, the Arab caliphates borrowed Persian methods of administration, and Persian rulers left a model of tolerant, efficient government for later empires to copy. The ruling cultures were themselves hybrids, reshaped by the people they ruled.
Over time, many empires grew more inclusive. Roman citizenship began as a privilege of the city of Rome and was slowly extended outward, until in 212 CE the emperor Caracalla granted it to all free inhabitants of the empire. Men from Spain, Gaul and North Africa became senators, generals and even emperors, and conquered peoples came to see themselves as Romans. Harari presents this as a common imperial cycle: conquest, then gradual assimilation, until the conquered adopt the imperial culture as their own and the old distinction between rulers and subjects fades.
That leaves an uncomfortable legacy. Most modern cultures grew from imperial foundations, and anti-imperial movements often fought empires with the empires’ own tools. Indian nationalism, Harari notes, was argued largely in English and drew on British liberal ideas. Trying to strip away imperial influence to recover some untouched authentic culture is, in his view, usually impossible, because nearly every culture is a product of past mixing. The same imperial legacy runs through the ideas of universal citizenship, a community of believers and a universal church, which reached beyond tribe and ethnicity and helped prepare the ground for modern notions of human rights. The challenge Harari leaves is how to keep the cosmopolitan side of that inheritance while rejecting the domination that came with it.
Chapter 12
The Law of Religion
The third great unifier is religion, which Harari defines as a system of human norms and values founded on belief in a superhuman order. That definition matters because it explains religion’s social power: when rules are said to come from beyond human reach, they are much harder to challenge. For most of history, local animist beliefs tied spirits to particular places and peoples. The big shift came with religions that claimed to hold for everyone, everywhere, and that set out to win converts.
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The monotheist religions expelled the gods through the front door with a lot of fanfare, only to take them back in through the side window.
Yuval Noah Harari
Harari traces this through polytheism, which he portrays as surprisingly tolerant. Polytheists accepted that other peoples had their own gods and were often happy to add foreign deities to their pantheons. Many believed in a supreme force above even the gods, such as the Greek idea of Fate, which not even Zeus could defy. Because that force was indifferent to human pleas, people addressed their prayers to lesser gods who might actually help. The Romans welcomed conquered peoples’ gods and persecuted Christians mainly because they refused to honor the emperor, a political offense more than a theological one.
Monotheism changed the stakes. Early Judaism probably began by asking Israelites to worship only their own god while not denying that others existed. It later became the claim that there was only one god at all, which made every other belief not just different but false. When this idea took universal and missionary form in Christianity and Islam, and allied itself with empire, it helped remake the world. Christianity went from persecuted sect to state faith once the emperor Constantine converted, and Islam spread with Arab conquests. Harari notes an irony: monotheist traditions filled up with saints, angels and demons that look a lot like the old pantheons.
The chapter’s final move is its most provocative. Harari argues that modern ideologies like liberalism, communism, capitalism and nationalism are best understood as religions too, even without gods, because each offers a complete system of values presented as truth. This helps explain how a modern society can accept evolution as fact while treating human rights as sacred. Science describes how things are, but it cannot say what is worth pursuing. Deciding to spend billions on cancer research rather than on the mating habits of beetles is a value judgment, not a scientific one. In the modern world, he suggests, these secular faiths supply the goals, and science supplies the means.
Chapter 13
The Secret of Success
Looking back, it is tempting to believe that history had to unfold the way it did. Harari argues that this impression is an illusion created by hindsight. The book’s final chapter on unification asks why certain cultures came to dominate, and his answer is that we can identify contributing factors but never a single inevitable cause. Historical outcomes emerge from countless decisions, accidents and circumstances, and small changes early on can produce enormous differences later.
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History cannot be explained deterministically and it cannot be predicted because it is chaotic.
Yuval Noah Harari
To explain why prediction is so hard, Harari draws a useful distinction between two kinds of chaotic systems. A first-order chaotic system, like the weather, is complicated but does not react to forecasts. Predicting rain does not make it more or less likely to fall. A second-order chaotic system does react to predictions about it, and history belongs to this category, as do markets and politics. If people learn of a forecast, they change their behavior, and the forecast may undo itself. Harari’s example is Karl Marx. Once Marx predicted that capitalism would end in a workers’ revolution, capitalists and workers alike read him and adjusted, and the revolution he foresaw did not arrive as expected in the countries he had in mind.
This framework also shapes how Harari treats the big question of why Europe came to rule so much of the world rather than China or the Islamic empires. There was nothing in European genes, geography or culture that guaranteed it. Some conditions made it more likely; Europe’s political fragmentation, for instance, encouraged competition and experimentation. But the same factors could easily have produced different results under slightly different circumstances. Historians and the public alike tend to impose a tidy order on the past, telling stories in which the winners were always destined to win.
Harari insists this view is liberating rather than bleak. If the present was not inevitable, then it is not fixed either, and human choices genuinely matter. He argues that the real value of studying history is not to forecast the future but to widen our imagination. Seeing that our world is the product of chance and contingency lets us recognize that things could be otherwise, and that current arrangements are neither natural nor permanent. It also asks for humility: just as past actors could not foresee the long-run results of what they did, neither can we.
Chapter 14
The Discovery of Ignorance
Some 500 years ago, a revolution began that would give humans power beyond anything their ancestors could imagine. Harari argues that its essence was not a new discovery but a new admission: we do not know. Earlier traditions of knowledge, whether Christian, Muslim, Buddhist or Confucian, generally assumed that everything important was already known. The gods, the prophets or the wise ancients had revealed the essential truths, and the task of scholars was to study and interpret the old texts. If a question was not answered there, it probably was not important.
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Modern science is based on the Latin injunction ignoramus – ‘we do not know’.
Yuval Noah Harari
Modern science starts from the opposite premise. Its motto might be the Latin word ignoramus, meaning we do not know. Scientists assume that even their most cherished theories may be incomplete or wrong, and they look for answers in new observations and experiments rather than in older books. Science also replaced grand stories with mathematics. Instead of weaving everything into one complete narrative, it describes pieces of the world with numbers and tests those descriptions against evidence. Its knowledge is always provisional, which is exactly what allows it to improve.
The second ingredient was a link between knowledge and power. Premodern learning seldom produced new technology, because its goal was to preserve wisdom, reach spiritual insight or maintain social harmony. The Scientific Revolution tied the admission of ignorance to a promise of progress: if we investigate what we do not know, we can gain new abilities to cure disease, grow more food and bend the world to our will. Knowledge came to be judged largely by what it lets us do.
This created a powerful feedback loop. Research costs money, and the money came from states and investors who expected returns in the form of weapons, medicines and growth. Those returns funded more research. Harari’s contrast between two famous voyages captures the new spirit. The Chinese admiral Zheng He led enormous fleets across the Indian Ocean between 1405 and 1433, but his missions were displays of power that assumed China already had the knowledge that mattered. James Cook’s Pacific voyages from 1768 to 1779 carried astronomers and botanists, because the British recognized they did not know what lay out there and believed finding out would pay. The belief that the future could be better than the past, and that ignorance was a door rather than a wall, was the seed of modern science, empire and capitalism alike.
Chapter 15
The Marriage of Science and Empire
Why did a handful of European states, small and on the edge of the world economy in 1500, come to dominate the globe? Harari’s answer centers on a partnership. Modern science and European imperialism grew up together, each feeding the other. Earlier empires, Roman, Mongol or Ottoman, conquered lands they already knew about and showed little interest in systematically studying them. European conquerors sailed into the unknown and brought scientists with them, treating each new land as both a prize and a puzzle.
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Both scientist and conqueror began by admitting ignorance – they both said, ‘I don’t know what’s out there.’
Yuval Noah Harari
Cook’s first voyage in 1768 is the showcase. Officially it was a scientific mission to watch the transit of Venus from Tahiti, and the ship carried astronomers and naturalists, including the botanist Joseph Banks. But Cook also carried orders to look for a hoped-for southern continent and claim new lands for Britain. The expedition mapped New Zealand and the east coast of Australia, gathered huge collections of unknown plants and animals, and helped pave the way for British colonization of Australia, with devastating results for its original inhabitants. Science and conquest were two sides of the same journey. Napoleon’s invasion of Egypt in 1798 followed the same pattern, bringing 165 scholars who produced the vast Description de l’Égypte.
India shows how knowledge became a tool of rule. British surveyors mapped the subcontinent with new precision, census-takers counted and sorted its people, and scholars studied its languages, religions and history. William Jones and his colleagues founded the Asiatic Society in 1784 to study Indian languages and culture, not only out of curiosity but to understand, and so govern, the people they ruled. Harari notes that for many imperialists this was not cynical: they sincerely saw learning about the world as both a duty and a practical need. Whole fields such as archaeology, ethnography and comparative linguistics took shape inside this imperial setting, and botanical knowledge helped move profitable crops like rubber and tea to new colonies.
The partnership had a dark side. The more Europeans measured and classified the world, the more some of them used supposedly objective science to rank humanity, with themselves on top. Racial theories that measured skulls and sorted peoples into hierarchies gave moral cover to exploitation. Museums and botanical gardens in European capitals filled with objects and specimens taken from colonies, and non-European knowledge was often dismissed as superstition. Harari’s verdict is that science and empire produced extraordinary advances and extraordinary harm together, and that much of what we treat as neutral knowledge still carries marks of that marriage.
Chapter 16
The Capitalist Creed
For most of human history, the economy stayed roughly the same size year after year. People assumed the total supply of wealth was fixed, so one person’s gain had to be another’s loss. Harari argues that modern capitalism overturned this assumption with a new article of faith: the economy can grow, and growth can keep going. That belief changes everything, because if tomorrow will be richer than today, it makes sense to lend and borrow against the future.
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Credit enables us to build the present at the expense of the future.
Yuval Noah Harari
This is why credit sits at the heart of the capitalist story. In a world without growth, lending is risky and grudging. In a world that expects growth, banks and investors will finance ventures on the strength of profits that do not exist yet. Harari describes a self-fulfilling cycle: trust in the future leads to credit, credit funds new enterprises, and those enterprises create real growth that justifies the trust. The first principle of the creed is that profits should be reinvested in production. A medieval noble with spare wealth might build a castle or throw a feast. The capitalist entrepreneur hires more workers, buys better equipment or opens new markets.
The creed also needed a moral makeover. Traditional religions had long warned against greed. Adam Smith’s idea of the invisible hand offered a different view: individuals pursuing their own gain end up benefiting everyone by creating jobs and goods. Greed, properly channeled, became a public service, and the promise that a growing pie would give everyone a bigger slice helped justify unequal shares in the present.
Harari shows how this logic powered European expansion. Joint-stock companies let many investors pool money and spread risk, making it possible to fund voyages and colonies too costly for any single merchant or even monarch. The Dutch East India Company is his key example of private capital running what amounted to an empire. The same machinery could go badly wrong. The Mississippi Company bubble in France showed how easily faith in future profits could inflate into a speculative frenzy that collapsed and damaged public trust. And the pursuit of profit could override ethics entirely, as in the Atlantic slave trade, which was financed and organized through ordinary capitalist mechanisms. The creed has delivered centuries of real growth, Harari concludes, which is part of why it is now so hard for us to imagine any alternative.
Chapter 17
The Wheels of Industry
The capitalist faith in endless growth ran into a hard physical limit: energy. Before modern times, almost all the energy humans could use came from plants turning sunlight into food and fuel, plus some help from wind and water. The total was roughly fixed by how much land was farmed, so if a king wanted a new palace, peasants went hungrier. The Industrial Revolution broke this ceiling by teaching humans to convert one form of energy into another. The steam engine, which turned heat from burning coal into motion, was the pivotal invention. For the first time, people could tap enormous stores of energy that did not depend on this year’s harvest.
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The supreme commandment of the rich is ‘Invest!’ The supreme commandment of the rest of us is ‘Buy!’
Yuval Noah Harari
Industry changed time itself. Farmers and artisans had followed the sun, the seasons and the task at hand. Factories demanded that hundreds of workers start and stop together, in step with machines. Precise, cheap clocks spread, and the factory whistle became a symbol of new discipline. Railways and later global networks required everyone to follow the same schedule, which led to standardized time zones. Schools adopted similar timetables, and even leisure became scheduled. Harari sees this as one of industry’s most lasting effects: we have absorbed mechanical time so completely that we plan our free hours with the precision of a production line.
Industry also reshaped work, cities and the globe. Mechanization and artificial fertilizers let far fewer farmers feed far more people, freeing workers for factories in growing cities. Industrial powers needed raw materials such as cotton, rubber, metals and oil, and markets for their goods, which they found in colonies. Steam-powered gunboats and mass-produced weapons gave small European forces crushing advantages. The gap between industrial and non-industrial regions grew into a chasm that shaped world politics for two centuries.
Finally, mass production created a new problem: who would buy all those goods? The answer was a new ethic, consumerism. For most of history, nearly every culture praised frugality. The modern economy needed people to keep buying, so what had been a vice became a virtue. Advertising taught people that happiness comes from purchases and that they deserve to treat themselves. Harari sums up the resulting deal neatly: the rich are encouraged to invest and save, while everyone else is encouraged to buy. The result is a self-feeding cycle of production and consumption that has created unprecedented abundance alongside new kinds of debt, dissatisfaction and strain on the planet.
Chapter 18
A Permanent Revolution
Earlier revolutions eventually settled down. The Scientific and Industrial Revolutions have not. Harari argues that the modern world is defined by change that keeps accelerating, driven by the loop between science, empire and capital. Traditional societies could pass customs and skills down for centuries with little alteration. Today, each generation grows up in a noticeably different world from its parents, which brings vast gains in health and comfort but also a constant sense of instability.
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Yet all of these upheavals are dwarfed by the most momentous social revolution that ever befell humankind: the collapse of the family and the local community and their replacement by the state and the market.
Yuval Noah Harari
The most profound upheaval, in Harari’s telling, happened in our closest relationships. For millennia, the family and the local community were everything. They supplied work, education, health care, welfare, justice and protection. If you fell ill or fell on hard times, your relatives and neighbors were your only safety net. Over the past two centuries, the state and the market stepped in and took over these roles. Public schools educate children, hospitals provide care, pensions support the old, police and courts settle disputes, and the market offers jobs, insurance and every service one could want.
The state and market made individuals an offer: become an individual. Marry whomever you choose, pursue any career, move wherever you like, and we will look after you. This was genuinely liberating. People escaped the often suffocating authority of family patriarchs and tight village communities, and women in particular gained freedoms that traditional structures had long denied them. But the deal had a cost. Families shrank from extended clans to nuclear households, and even many of the nuclear family’s duties were handed off to kindergartens and care homes. Many modern people are freer than ever and also lonelier, tied to others mainly through transactions and paperwork.
Into the empty space left by vanishing communities stepped what Harari calls imagined communities, groups of people who do not know each other but believe they belong together. Nations are one kind; consumer tribes, such as fans of a brand or team, are another. They offer a sense of belonging but cannot match the warmth of a village where everyone knows your name. Harari also notes the fragility of the new arrangement. It works as long as vast, impersonal institutions keep functioning, and when states fail or markets crash, people may find they have lost the old safety nets without a reliable replacement. It is one of the largest experiments in social organization humans have ever run, and its long-term effects remain unknown.
Chapter 19
And They Lived Happily Ever After
After hundreds of pages about power, Harari pauses to ask the question historians usually skip: has all this made us happier? More food, better medicine and greater wealth should, in theory, have made modern people far more content than foragers or medieval peasants. Harari finds the answer far less obvious. Research on well-being suggests that once basic needs are met, extra wealth adds surprisingly little. Rising expectations swallow many gains, because as conditions improve, what we hope for rises too. And we judge our lives by comparison with those around us rather than by absolute standards.
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If happiness is determined by expectations, then two pillars of our society – mass media and the advertising industry – may unwittingly be depleting the globe’s reservoirs of contentment.
Yuval Noah Harari
He then explores a biological view. On this account, happiness is the pleasant sensation produced by a system of nerves and biochemicals such as serotonin, dopamine and oxytocin. Evolution built that system not to make us happy but to keep us surviving and reproducing. Pleasure rewards useful acts like eating, sex and bonding, but it has to fade quickly. An ancestor who felt blissful forever after one good meal would have stopped looking for the next and starved. So our moods tend to return to a set point, like a thermostat. Good news brings a spike and bad news a slump, but most people drift back toward their usual level. Harari describes this as a treadmill: we keep running after the next achievement, expecting it to satisfy us, and stay in the same place.
If this view is right, a medieval peasant and a modern banker might have similar average happiness despite vastly different lives, and much of history’s progress may have done little for how people feel. Harari also considers the view that happiness depends on meaning, not just pleasure. A parent or researcher who works hard under stress may still judge life deeply worthwhile. He also asks whether the loss of close families and tight communities has cancelled out some of the gains of material progress, since freedom from old constraints came with less belonging.
The biochemical view also implies an uncomfortable inequality, since some people seem born with cheerful chemistry and others with gloomy chemistry. Harari notes that Buddhism and other ancient traditions anticipated part of this insight by teaching that happiness comes from within rather than from outside circumstances. He also looks ahead: if happiness is biochemical, future humans might try to engineer it directly through drugs, meditation techniques or biotechnology. That could prove a deeper revolution than any political or economic one, though it raises hard questions about authenticity and what a good life really is. Throughout, he admits that we lack reliable evidence about how people in the past actually felt, so firm conclusions remain out of reach.
Chapter 20
The End of Homo Sapiens
For four billion years, every living thing was shaped by natural selection. Harari’s final chapter argues that this era is ending. Humans are beginning to replace natural selection with intelligent design, and the designers are us. He identifies three routes by which Sapiens might transform itself or be replaced, and suggests that they could reshape humanity within the next century or two.
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Since we might soon be able to engineer our desires too, perhaps the real question facing us is not ‘What do we want to become?’, but ‘What do we want to want?’
Yuval Noah Harari
The first route is biological engineering: deliberately changing organisms at the level of their genes and bodies. People have bred plants and animals for thousands of years, but genetic engineering allows precise, fast changes that bypass evolution entirely. Scientists have already altered mice and many other organisms, and projects like the mapping of the human genome bring similar possibilities closer for people. Parents might one day choose or modify traits in their children, from resistance to disease to aspects of intelligence and temperament. Harari’s greatest worry is social: if the wealthy can buy genetic upgrades that the poor cannot, humanity could split into biological castes far more rigid than any hierarchy in history.
The second route is cyborg engineering, which merges living bodies with machines. In a sense it has already started with pacemakers, cochlear implants and retinal implants, and bionic limbs that respond to nerve signals. Researchers are working on brain-computer interfaces that would let people control devices by thought or link minds directly to machines. As these tools improve, the line between healing and upgrading blurs, and a being with extensive electronic parts might be so different from us that it deserves to be called a new species.
The third route, the most radical, is to create entirely inorganic life, such as computer programs capable of learning and evolving, perhaps even of consciousness. Efforts to map and simulate the brain raise the possibility that minds could exist in silicon rather than cells. Harari cautions that he cannot predict which route will win or what the future will look like; his point is that the stakes are unprecedented. Our descendants could be as different from us as we are from Neanderthals. He closes with a warning in place of a forecast. We are gaining godlike powers over life while remaining unsure what we want. We are racing ahead with these technologies without a clear idea of what kind of beings we want to become, and he urges readers to face the ethical and philosophical questions before the changes become irreversible.
Yuval Noah Harari is an Israeli historian and one of the most widely read nonfiction authors of the twenty-first century. He was born in 1976 in Israel, earned his doctorate in history at the University of Oxford, and went on to teach in the Department of History at the Hebrew University of Jerusalem. His early academic work focused on medieval and military history before he turned to world history on the grandest scale.
Sapiens grew out of an introductory world history course Harari taught at the Hebrew University. It was first published in Hebrew in 2011, and the English edition appeared in 2014, becoming an international bestseller translated into dozens of languages. He followed it with Homo Deus: A Brief History of Tomorrow, about the future of humanity, and 21 Lessons for the 21st Century, about present-day challenges. Later works include Sapiens: A Graphic History, the children’s series Unstoppable Us, and Nexus, a history of information networks published in 2024. Together his books have sold tens of millions of copies. Harari is also a cofounder of Sapienship, a social impact company focused on education and storytelling, and he speaks widely on technology, artificial intelligence and the future of humankind.
What is Sapiens: A Brief History of Humankind about?
Sapiens tells the story of our species from its beginnings in East Africa to the present, organized around three great turning points. The Cognitive Revolution, about 70,000 years ago, gave humans the ability to believe in shared fictions and cooperate in large numbers. The Agricultural Revolution, which Harari provocatively calls history’s biggest fraud, tied people to fields and built the first kingdoms. The Scientific Revolution, beginning about 500 years ago, joined science to empire and capitalism and gave humans enormous power. Along the way, Harari explains how money, empires and religions unified humankind, and he closes by asking whether all this progress made us happier and what biotechnology may do to us next.
What is the main idea of Sapiens?
The book’s central idea is that Homo sapiens came to rule the planet because it can cooperate flexibly in very large numbers, and it can do that because it believes in shared stories. Gods, nations, money, corporations and human rights exist only in our collective imagination, yet they let millions of strangers work together. Harari calls these intersubjective realities or imagined orders. A second recurring theme is that growing collective power does not guarantee individual well-being. Farming, for example, made the species more numerous while making many individual lives harder, and the book repeatedly asks whether historical progress has actually made people happier.
What are the key takeaways from Sapiens?
First, for most of history several human species coexisted, and Sapiens was once an unremarkable animal. Second, our superpower is shared fiction, which enables large-scale cooperation. Third, humans were destroying ecosystems long before industry, driving waves of large-animal extinctions as they spread. Fourth, the Agricultural Revolution increased population but often worsened daily life, an example of the luxury trap. Fifth, social hierarchies such as caste, race and gender are imagined orders that sustain themselves through vicious circles. Sixth, money, empire and universal religions pushed humanity toward a single global order. Seventh, modern science began with admitting ignorance. Finally, material progress has not clearly increased happiness, and new technologies may soon transform what being human means.
What does Harari mean by the Cognitive Revolution?
The Cognitive Revolution is Harari’s name for a change in how Sapiens thought and communicated around 70,000 years ago. Its hallmark was a new kind of language that could describe not only the real world but things that do not exist, such as spirits, tribal ancestors and, later, nations and companies. Believing in the same stories allowed strangers to cooperate far beyond the roughly 150 people who can bond through personal relationships. It also let humans change their behavior quickly by changing their stories, instead of waiting for genetic evolution. Harari argues this, more than tools or brain size, explains why Sapiens spread worldwide and outcompeted other human species.
Why does Harari call the Agricultural Revolution history’s biggest fraud?
Harari argues that farming promised abundance but delivered harder lives for most individuals. Early farmers worked longer hours than foragers, ate a narrower diet dependent on a few crops, suffered more disease in crowded villages and faced famine when harvests failed. Their skeletons show they were generally shorter and less healthy. Yet farming spread because it supported far larger populations, and larger groups could displace foragers. The shift happened gradually through sensible-seeming choices, and once populations grew, going back was impossible. Harari even suggests that wheat domesticated humans, since the plant spread across the world while people devoted their lives to its care. The surplus mostly fed elites.
Is Sapiens worth reading?
For most curious readers, yes. Sapiens is known for compressing an enormous span of time into a readable narrative and for provocative arguments that reframe familiar topics, such as treating money as a system of trust or capitalism as a kind of religion. Its big ideas, especially shared fictions and imagined orders, give readers a lens they can apply to news, business and politics. It is best read as an argument rather than a neutral textbook. Harari takes strong positions, and some specialists dispute parts of his case, so readers get the most from it when they treat its bold claims as prompts for thinking rather than final answers.
Who should read Sapiens?
Sapiens suits general readers who want a big-picture view of human history without needing any background in anthropology, economics or biology. It is especially rewarding for people who like connecting ideas across fields, since it moves from evolution and archaeology to religion, finance, empire and biotechnology. Students looking for a framework to organize world history, professionals curious about why institutions like money and corporations work, and anyone interested in questions about happiness and the future of humanity will find plenty to think about. Readers who want detailed coverage of specific events, dates and rulers may prefer a more traditional history, as Harari deliberately favors broad patterns over narrative detail.
How long does it take to read Sapiens?
The widely sold US paperback edition runs to roughly 460 pages, so most readers need somewhere around 12 to 15 hours at an average pace. The book is divided into four parts and twenty fairly self-contained chapters, which makes it easy to read in short sessions of a chapter or two. Some sections, such as those on money, empire and religion, move quickly, while others invite slower reading because they challenge common assumptions. A summary like this one covers the main arguments of every chapter in well under an hour, which can help readers decide whether to take on the full book or refresh their memory afterward.
What are imagined orders and intersubjective reality?
Harari distinguishes three kinds of reality. Objective things, such as gravity, exist no matter what anyone believes. Subjective things, such as a personal pain, exist inside one mind. Intersubjective things exist in the shared beliefs of many people, and money, nations, laws and corporations all belong here. An imagined order is a social system built on such shared beliefs. Harari explains that these orders last because they are built into physical things like architecture, they shape our personal desires, and they depend on so many believers that no single person can undo them. They also tend to claim they are natural or divine rather than human inventions, which makes alternatives hard to imagine.
How does Sapiens compare to Guns, Germs, and Steel?
Both books tackle the long sweep of human history for general readers, and both ask why some societies came to dominate others. Jared Diamond’s Guns, Germs, and Steel leans heavily on geography, crops, animals and disease to explain that question. Sapiens ranges more widely, from human evolution to the future of biotechnology, and puts more weight on ideas and shared beliefs, arguing that fictions like money, religion and empire drove history. Harari is also skeptical of any single deterministic explanation, stressing chance and the way history reacts to predictions. Readers who enjoy one usually enjoy the other, and together they offer complementary perspectives.
What does Harari predict about the future of humanity?
In the final chapter, Harari argues that natural selection is giving way to intelligent design by humans. He outlines three routes: biological engineering, such as altering genes; cyborg engineering, which merges bodies with devices like implants and brain-computer interfaces; and the creation of inorganic life, such as intelligent software. He does not claim to know which will prevail, but he warns that our descendants could be as different from us as we are from Neanderthals. His biggest concerns are that enhancement could create rigid biological inequality, and that we are gaining godlike powers without knowing what we want.
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