Sapiens by Yuval Noah Harari: Summary & Notes

Front cover of Sapiens by Yuval Noah Harari.

In short

Sapiens is the incredibly popular narrative of human history by Yuval Noah Harari that tells the story of the genus Homo from its very origins up to modern times. In a way the question the book answers is: how could one seemingly insignificant species conquer the entire world, and become so deadly and successful? The answer to that question relates to our cognitive abilities, but the invention of fiction also plays a big role. Telling stories, creating myths, and in general believing in abstract things allowed humankind to farm, build order, invent money, bureaucracy, religion, et cetera.

Harari takes the reader through the cognitive, agricultural, scientific, and industrial revolutions and at the end asks an interesting question: are we any happier for having followed this evolutionary road? The answer is arguably no – we have become more powerful as a species, but this not always coincided with improvement of the well-being of individuals.

In the end, Sapiens is an entertaining and informative narrative, and – even if you don’t buy all of Harari’s arguments – it will still make you think about human progress and the story of our species.

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Book Summary & Notes

All text between quotation marks is taken directly from the book.

The Cognitive Revolution

“It’s a common fallacy to envision these species as arranged in a straight line of descent, with Ergaster begetting Erectus, Erectus begetting the Neanderthals, and the Neanderthals evolving into us. This linear model gives the mistaken impression that at any particular moment only type of human inhabited the earth, and that all earlier species were merely older models of ourselves. The truth is that from abut 2 million years ago until around 10,000 years ago, the world was home, at one and the same time, to several human species.”

“We assume that a large brain, the use of tools, superior learning abilities and complex social structures are huge advantages. It seems self-evident that these have made humankind the most powerful animal on earth. But humans enjoyed all of these advantages for a full 2 million years during which they remained weak and marginal creatures. Thus humans who lived a million years ago, despite their big brains and sharp stone tools, dwelt in constant fear of predators, rarely hunted big game, and subsisted mainly by gathering plants, scooping up insects, stalking small animals, and eating the carrion left behind by other more powerful carnivores.”

“Most top predators of the planet are majestic creatures. Millions of years of dominion have filled them with self-confidence. Sapiens by contrast is more like a banana-republic dictator. Having so recently been one of the underdogs of the savannah, we are full of fears and anxieties over our position, which makes us doubly cruel and dangerous. Many historical calamities, from deadly wars to ecological catastrophes, have resulted from this over-hasty jump.”

Most groups are usually limited to 150 people – above that number it becomes impossible to lead and organize the group in traditional ways. So how did Sapiens manage to create cities with thousands of people? The answer is fiction.

Any large-scale human cooperation – whether a modern state, a medieval church, an ancient city or an archaic tribe – is rooted in common myths that exist only in people’s collective imagination. Churches are rooted in common religious myths. […] States are rooted in common national myths. […] Judicial systems are rooted in common legal myths. […]
Yet none of these things exist outside the stories that people invent and tell one another. There are no gods in the universe, no nations, no money, no human rights, no laws and no justice outside the common imagination of human beings.”

Telling effective stories is not easy. The difficulty lies not in telling the story, but in convincing everyone else to believe it. Much of history revolves around this question: how does one convince millions of people to believe particular stories about gods, or nations, or limited liability companies? Yet when it succeeds, it gives Sapiens, immense power, because it enables millions of strangers to cooperate and work towards common goals. Just try to imagine how difficult it would have been to create states, or churches, or legal systems if we could speak only about things that really exists, such as rivers, trees and lions.

“The immense diversity of imagined realities that Sapiens invented, and the resulting diversity of behaviour patterns, are the main components of what we call ‘cultures’. Once cultures appeared, they never cased to change and develop, and these unstoppable alterations are what we call ‘history’.”

The average forager had a more diverse skill set than a modern human – currently we don’t know much about our environment because we simply don’t have to. Instead, our knowledge is usually concentrated in one particular area. As a result we can say that the average person today knows less, and has a lower skill set, than an average forager. But as the human collective we know far more.

Humans were foragers for hundreds of thousands of years. It is what we were adapted to, and archaeological evidence shows that starvation and malnutrition were less common than during the agricultural revolution, when humans starting farming rather than foraging. This is because their diet was diverse; while farmers focus on a few select crops that probably don’t provide all the nutrition needed.

Sapien colonization of the world coincided with animal extinctions and ecological disasters. This was especially true for big animals: before inventing the wheel or writing, more than half of the big animals (>50kgs) went extinct.

The Agricultural revolution

The domestication of animals and plants happened during the agricultural revolution and has seen little progress since. What could be domesticated, was mostly domesticated – >90% of our current calorie intake comes from plants that were domesticated between 9000 and 3500 BC (wheat, rice, corn, potatoes, barley, etc). This is also why the agricultural revolution happened in certain places like the Middle East, China and Central America: it is where the plants and animals that could be domesticated were.

The lives of people during the agricultural revolution were harder than those of foragers. Hunter-gatherers had a more varied diet, and had less risk of starvation or disease (which increased during the domestication of animals, and the creation of permanent villages). More food was available during the agricultural revolution, but that didn’t lead to more leisure; rather it meant a population explosion and the creation of an upper ruling class.

“The currency of evolution is neither hunger nor pain, but rather copies of DNA helixes. Just as the economic success of a company is measured only by the number of dollars in its bank account, not by the happiness of its employees, so the evolutionary success of a species is measured by the number of copies of its DNA. If no more DNA copies remain, the species is extinct, just as a company without money is bankrupt. […] This is the essence of the Agricultural Revolution: the ability to keep more people alive under worse conditions.”

If conditions during the agricultural revolution were worse, why didn’t people go back to foraging? One reason is that the new population could not be supported by foraging alone, and another that this was a slow revolution and so people got used to it and forgot there was another way to live.

“One of history’s few iron laws is that luxuries tend to become necessities and to spawn new obligations. Once people get used to a certain luxury, they take it for granted. Then they begin to count on it. Finally they reach a point where they can’t live without it.”

With the food surpluses during the agricultural revolution, ruling classes and elites were created – a new social order where 90% of the people worked the fields and a minority profited from the surplus. This helped start politics, philosophy, wars, art, and the creation of monuments and temples.

History is something that very few people have been doing while everyone else was ploughing fields and carrying water buckets.

Imagined order (like religion, or capitalism) is something that people belief – but why do they belief in it? First because it’s embedded in the real world (like individualism and having separate rooms for each child). Second, because it shapes our desires (consumerism and buying products, or building pyramids in ancient Egypt. Third, because it’s inter-subjective – imagined order is not just something one person thinks, it’s collective. So even if one person stops believing in it, you would still have to convince millions of others.

“There is no way out of the imagined order. When we break down our prison walls and run towards freedom, we are in fact running into the more spacious exercise yard of a bigger prison.”

“The most important impact of script on human history is precisely this: it has gradually changed the way humans think and view the world. Free associations and holistic thought have given way to compartmentalisation and bureaucracy.”

How can we distinguish between what is biologically determined and what people try to justify as biologically determined? The rule of thumb the book presents is: “biology enables, culture forbids.” Nothing that is possible is unnatural or against the laws of nature – it’s just the culture that forbids some behaviour.

The Unification of Humankind

“Perceiving the direction of history is really a question of vantage point. When we adopt the proverbial bird’s-eye view of history, which examines developments in terms of decades or centuries, it’s hard to say whether history moves in the direction of unity or of diversity. However, to understand long-term processes the bird’s-eye view is too myopic. We would do better to adopt instead the viewpoint of a cosmic spy satellite, which scans millennia rather than centuries. From such a vantage point it becomes crystal clear that history is moving relentlessly towards unity.”

Universal order started after the first millennium BC in which people could imagine the human race as a single entity. There were three different “orders”: monetary order (single market, all humans are potentially customers), imperial order (single empire, all humans are potentially subjects), and religious order (single truth, all humans are potentially subjects.

Money is the perfect example of human fiction: it’s inherently not worth anything, but we are willing to trust money, and that other people will accept it (usually backed up by a king or state). This is also why financial systems are very closely tied to political and social systems.

Because of the close links to political order, counterfeiting money has always carried heavier punishments than other crimes. “Counterfeiting is not just cheating – it’s a breach of sovereignty, an act of subversion against the power, privileges and person of the king.”

What is an empire? A political order that has a cultural diversity (rule of distinct peoples) and flexible borders (growing and digesting more countries and peoples).

Most religions in the past were very local, but in order for religion to expand it must be universal (true for everyone, not just people of, say, a single valley) and missionary (insistence on spreading belief). Today’s most popular religions, like Islam and Christianity, exhibit both characteristics.

After two millennia of monotheistic religions, polytheism seems strange to us. But it has clear benefits; it is extremely tolerant for example. Polytheistic religions might believe in a single supreme (but disinterested) god, but they also belief in many biased smaller gods – so it is not difficult to accept the existence of other gods, and no need to prosecute other religions.

Monotheistic religions, on the other hand, are usually intolerant and violent. In one single dispute between Catholics and Protestants, the St. Bartholomew’s Day Massacre, more Christians were killed in 24 hours than in total in the polytheistic Roman Empire.

Monotheism is not really monotheistic though – “The average Christian believes in the monotheist God, but also in the dualist Devil, in polytheist saints, and in animist ghosts. Scholars of religion have a name for this simultaneous avowal of different and even contradictory ideas and the combination of rituals and practices taken from different sources. It’s called syncretism. Syncretism might, in fact, be the single great world religion.”

“This is one of the distinguishing marks of history as an academic discipline – the better you know a particular historical period, the harder it becomes to explain why things happened one way and not another. Those who have only a superficial knowledge of a certain period tend to focus only on the possibility that was eventually realised. They offer a just-so story to explain with hindsight why that outcome was inevitable. Those more deeply informed about the period are much more cognisant of the roads not taken.”

History is not guided by deterministic laws – meaning what happened is mostly led by coincidence, and as a result cannot be predicted neither. This why history is a ‘level two’ chaotic system. Level one chaotic systems, like the weather, can be forecasted. Level two chaotic systems react to predictions (like financial markets, for example).

So if studying history cannot lead to proper predictions, why study it at all? “We study history not to know the future but to widen our horizons, to understand that our present situation is neither natural nor inevitable, and that we consequently have many more possibilities before us than we imagine.”

The Scientific Revolution

Before the scientific revolution started, not many people believed in progress. All that was good was in the past, and the world was in a slow decline. The myths of the Tower of Babel, Icarus, and the Golem showed that it was hubris for humankind to attempt to improve the world.

In 1750 there was an apparent equality between Europe, China and the Muslim world – but over the next few hundred years European dominance exploded. What was behind this? Two complementary answers: modern science and capitalism – even before they gained dominance and technological advances, Europeans were used to thinking and using science and capitalism, which laid a strong foundation for future expansion.

The idea that the past was better than the future also had big consequences in the credit markets: throughout the ages people didn’t belief the future could be better, so they didn’t want to extend too much credit. Wealth was limited, and business a zero-sum game – so if the total economy wasn’t growing why would you lend out your wealth?

While capitalism started as an economic theory explaining how money worked and economic growth worked, it turned into a sort of ethic: how we should behave and think.

Capital moves away from dictatorships were individuals and property rights are not protected, and flows into states that pay back loans on time and where the judicial system protects private rights. This explains, for example, why huge empires like the Spanish fail slowly start to fail – not paying back debts and not working honestly with creditors results in less flow of money, and thus limited possibilities for the government to finance war and expeditions.

The consumerist and capitalist ethics are a contradiction: one says to invest, the other to buy (random) things. But as throughout all the centuries, this shows a clear class distinction. The rich manage their assets, the poor buy things with money they don’t have.

Even though people might have suffered more throughout history than we currently do, can we say their lives were less happy? Probably not since they derived a meaningful life from different things – access to the afterlife for example. Today many people find meaning in their lives through seeking knowledge, or building companies, but this isn’t any more meaningful objective-speaking than what people pursued in the past.

“So perhaps happiness is synchronising one’s personal delusions of meaning with the prevailing collective delusions. As long as my personal narrative is in line with the narratives of the people around me, I can convince myself that my life is meaningful, and fin happiness in that conviction.”

The debate between science and intelligent design has an ironic twist: while it is clear that biologists are right on Darwinian evolution, intelligent design proponents might be right about the future. Natural selection is slowly being replaced by intelligent design through biological engineering, cyborgs, or creation of inorganic life.


“Seventy thousand years ago, Homo sapiens was still an insignificant animal minding its own business in a corner of Africa. In the following millennia it transformed itself into the master of the entire planet and the terror of the ecosystem. Today it stands on the verge of becoming a god, poised to acquire not only eternal youth, but also the divine abilities of creation and destruction.”

“Unfortunately, the Sapiens regime on earth has so far produced little that we can proud of. We have mastered our surroundings, increased food production, built cities, established empires and created far-flung trade networks. But did we decrease the amount of suffering in the world? Time and again, massive increased in human power did not necessarily improve the well-being of individual Sapiens, and usually caused immense misery to other animals.”

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