Sapiens
A Brief History of Humankind
by Yuval Noah Harari
summarized by Adrie Kuil
Brief summary
Three important revolutions shaped the course of history: The Cognitive Revolution of about 70,000 years ago, The Agricultural Revolution of around 12,000 years ago, and The Scientific Revolution that started 500 years ago. The ability of our language to transmit information about things that don’t exist, has enabled large numbers of strangers to work together successfully by believing in common myths. This has made Homo sapiens master of the world. The revolutions have enabled Homo sapiens to act in ways that go against the fundamental principles of natural selection.
Full summary
This summary is an informal write-up of my understanding of the key messages from the book A Brief History of Humankind by Yuval Noah Harari.
The Cognitive Revolution
We belong to Homo sapiens – the species sapiens (wise) of the genus Homo (man) of the family of the great apes. In Homo sapiens, the large brain is about 2-3 percent of total body weight, but consumes 25 percent of the energy of a body that is at rest. For 2 million years members of the genus Homo lived in constant fear of predators. Only in the last 100,000 years has man jumped to the top of the food chain. This happened so quickly that we are anxious and concerned about our position. By domesticating fire humans gained control of a potentially limitless force.
The Cognitive Revolution is the appearance of new ways of thinking and communicating between 70.000 and 30.000 years ago.
Homo sapiens needs to cooperate for survival and reproduction. It seems that our language evolved to enable gossip. The maximum size of a group bonded by gossip is about 150 individuals.
The unique feature of our language is its ability to transmit information about things that don’t exist, which enables us to imagine things collectively. Large numbers of strangers can work together successfully by believing in common myths. This cooperation revolves around convincing people to believe stories. We live in a dual reality: an objective reality, and an imagined reality that everyone believes in.
You can change the way people cooperate by changing their myths. The fast lane of cultural evolution bypasses the slow lane of genetic evolution. We can change our behaviour quickly without the need for genetic change. The Cognitive Revolution enables us to act in ways that go against the fundamental principles of natural selection. Trade requires trust, and it’s difficult to trust strangers. We are animals and our innate abilities are still shaped by our DNA.
For tens of thousands of years our ancestors hunted and gathered. We live in a post-industrial environment, but our hunter-gatherer minds think we’re still in the savannah. Living in nuclear families and having monogamous relationships could be incompatible with our biological software. Foragers moved house frequently and only had the most essential possessions.
Different imagined realities manifest themselves in different norms and values. These realities are cultural choices from among a huge number of possibilities. The dog was domesticated by Homo sapiens before the Agricultural Revolution, and through their co-evolution they learned to communicate well with each other.
Most foragers lived more interesting lives than farmers or industrial workers, and had better nutrition due to their varied diet. Foragers roamed in small bands that could not sustain epidemics. They were neither angels nor fiends, they were humans. Most scholars agree that the ancient foragers held animistic beliefs
Some 45,000 years ago Sapiens broke out of the Afro-Asia landmass and colonised Australia. This was the first time any large terrestrial mammal managed to make this crossing. Within a few thousand years virtually all giant Australian animals vanished.
Homo sapiens reached the American landmass about 16,000 years ago, and spread all over the continent within a few thousand years. This testifies to their unique ingenuity and supreme adaptability. Within a few thousand years most unique American species were gone.
The historical record makes Homo sapiens look like an ecological serial killer. Don’t believe tree-huggers who claim that our ancestors lived in harmony with nature. We are the deadliest species in the annals of biology. If more people were aware of how many species we’ve already eradicated, we might be more motivated to protect the surviving ones.
The Agricultural Revolution
The Agricultural Revolution was a revolution in the way humans lived, caused by domesticating a few animal and plant species. It began around 12,000 years ago, and 9,000 years later most people in the world were agriculturists. The Agricultural Revolution was history’s biggest fraud. The average farmer worked harder than the average forager, had a worse diet, and an excess of ailments, such as arthritis and hernias.
The essence of the Agricultural Revolution is the ability to keep more people alive under worse conditions. With the move to permanent villages and the increase in food supply, the population began to grow. People were unable to fathom the full consequences of their decisions. Permanent settlements brought infectious diseases, dependence on a single source of food exposed them to droughts, and bulging granaries attracted enemies. Population growth made it impossible to go back to the old ways of living. Luxuries tend to become necessities and give rise to new obligations. Humanity’s search for an easier life transformed the world in ways nobody envisioned or wanted. It might well be that foragers switched to agriculture to enable the building of temples.
The evolutionary success of a species is measured by the number of copies of its DNA. This measure doesn’t take into account individual suffering and happiness. The domestication of animals is founded on a series of brutal practices. We have to consciously consider how evolutionary success translates into individual experience.
The vast majority of farmers lived in permanent settlements. Humans became attached to their home, separated from their neighbours, and much more self-centred. They created artificial environments meant only for them, their plants and their animals. Farmers always had to keep the future in mind, as they were at the mercy of droughts, floods and pestilence. Everywhere rulers and elites sprang up, living off the peasants’ surplus food.
People crammed together first into villages, then into towns, and finally into cities. Humans evolved for millions of years in small bands of a few dozen individuals. The few millennia from the agricultural revolution to the appearance of cities did not provide enough time to evolve an instinct for mass cooperation.
Most human cooperation networks have been oriented towards oppression and exploitation. The social norms that sustained these networks were based on the belief in shared myths. The only place where universal principles of justice exist is in the imagination and myths of Sapiens. Evolution is based on difference, not on equality. We believe in imagined orders not because they are objectively true, but because they enable us to cooperate effectively. Homo sapiens has no natural rights. An imagined order is always in danger of collapse because it depends upon myths, and myths vanish once people stop believing them. Our desires are shaped by the dominant myths of the imagined order we live in, e.g. by consumerism and romanticism. To change an imagined order, we must first believe in an alternative imagined order.
An objective phenomenon exists independently of human consciousness and beliefs. A subjective phenomenon is something that exists depending on the consciousness and beliefs of a single individual. The inter-subjective is something that exists within the communication network linking the subjective consciousness of many individuals. The impact on the world of inter-subjective phenomena can be enormous.
Empires generate huge amounts of information, like laws, procedures, transactions and taxes. The human brain has a limited capacity, is perishable, and is specialised in storing information that is useful for survival. Our brain did not adapt to store and process numbers.
Around 5,000 years ago a system was invented for storing and processing large amounts of data outside the brain: writing. A few cultures developed systems to efficiently catalogue and retrieve written data. Around 3,000 years ago numbers were invented, based on the ten signs of 0 to 9. Script has gradually changed the way humans think and view the world: from free association and holistic thought to compartmentalisation and bureaucracy.
Complex human societies seem to require imagined hierarchies and unjust discrimination. Every imagined hierarchy denies its fictional origin, and claims to be natural, just and inevitable. Throughout history concepts of pollution and purity have played a leading role in enforcing social divisions. If you want to isolate any human group, the best way to do this is to convince everyone that these people are a source of impurity and pollution. This turns them into outcasts, untouchables.
In most cases social hierarchies are the result of accidental historical circumstances. People benefiting from these hierarchies want to be seen as just and objective, so they use religious and scientific myths to justify the hierarchies. By a vicious cycle of perpetuation and refinement a chance historical situation over time gets transformed into a rigid, cruel, unjust, discriminatory social hierarchy. Money comes to money, and poverty to poverty.
One hierarchy has been of supreme importance: the hierarchy of men and women. Almost everywhere men have got the better deal. Around the hard core of biological differences, layers of cultural ideas and norms have accumulated. How can we distinguish biological myths from what is really biologically determined? Biology enables, culture forbids.
From a biological perspective, nothing is unnatural. Evolution has no purpose. Biologically, humans are divided into males and females. Culturally, humans are divided into men and women. Patriarchy has been the norm in almost all agricultural and industrial societies. We don’t know the reason for this. Is it muscle power? Aggression? Different survival and reproduction strategies?
The unification of humankind
Culture is the network of artificial instincts created by shared myths and fictions. Every culture has its beliefs, norms and values, that are in constant flux. Every man-made order is packed with internal contradictions, for instance equality and individual freedom. Over the millennia small, simple cultures gradually combine into bigger and more complex civilisations.
Homo sapiens evolved to think of people as divided into ‘us’ and ‘them’. ‘Us’ was the group immediately around you, and ‘them’ was everyone else. Merchants, conquerors and prophets were the first people to foresee the potential unity of mankind.
Money is anything that people are willing to use in order to represent the value of other things for the purpose of exchanging goods and services. It enables people to compare quickly and easily the value of different commodities, to easily exchange one thing for another, and to store wealth conveniently. For complex commercial systems to function, some kind of money is indispensable. Everyone always wants money because everyone else also always wants money. Money is a psychological construct based on mutual trust.
By the late modern era the entire world was a single monetary zone, relying first on gold and silver, and later on trusted currencies such as the British pound and the American dollar. Money only asks us to believe that other people believe in it. Money is based on the universal principles of convertibility and trust. It replaces local traditions, intimate relations and human values with the laws of supply and demand. The trust is not invested in humans, but in money itself and the impersonal systems that back it.
An empire is a political order that has flexible borders, and that rules over a significant number of distinct peoples, each with a different culture. Empires are one of the main reasons for the drastic reduction in human diversity. Empire has been the world’s most common form of political organization for the last 2,500 years. The standard imperial toolkit included wars, enslavement, deportation and genocide. Empires also brought us philosophy, art, justice and charity.
Evolution has made Homo sapiens a xenophobic creature. Imperial ideology has tended to be inclusive and all-encompassing. This ideology played an important role in merging many small cultures into fewer big cultures. The process of assimilation was often painful and traumatic.
As of 2014 national states are fast losing their independence. A global empire is being forged before our eyes, ruled by a multi-ethnic elite, and held together by a common culture and common interests.
Religion has been the third great unifier of mankind, alongside money and empires. Social orders are fragile because they are imagined. The larger the society, the more fragile it is. Religion gives superhuman legitimacy to these fragile structures, and ensures social stability by placing some fundamental laws beyond challenge.
The first religious effect of the Agricultural Revolution was to turn plants and animals from equal beings into property. Much of ancient mythology is about humans promising everlasting devotion to the gods in exchange for mastery over plants and animals (abundant harvests and fertile flocks). Homo sapiens increasingly saw the world as a reflection of the relationship between gods and humans. Polytheism raised the status of humankind.
Polytheists believe in one supreme power that is unconcerned with the mundane desires and worries of humans. They also believe in many partial superhuman powers that they can rely on for help. These beliefs are advantageous for religious tolerance. With time some followers of polytheist gods began to believe their god was the only god. Thus were born monotheist religions. Monotheists tend to be much more prone to fanaticism and missionary zeal than polytheists. Monotheism is a kaleidoscope of monotheist, dualist, polytheist and animist legacies, jumbled together under a single divine umbrella.
During the first millennium BC natural-law religions began to spread that disregarded gods. For instance Buddhism holds that suffering is caused by the behaviour patterns of one’s own mind. Our mind should accept things as they are, without craving. A person who does not crave cannot suffer. The first principle of Buddhism: suffering exists, how do I escape it?
Religion is a system of human norms and values that is founded on belief in a superhuman order. The modern age has witnessed the rise of new natural-law religions, such as humanism, liberalism, communism, capitalism and nationalism. Humanism is a belief that Homo sapiens has a unique and sacred nature, which is fundamentally different from the nature of all other animals. Everything exists solely for the benefit of Homo sapiens.
Every point in history is a crossroads, with myriad paths forking off into the future. What looks inevitable in hindsight was far from obvious at the time. To acknowledge that history is not deterministic is to acknowledge that it is just a coincidence that most people today believe in nationalism, capitalism and human rights. History cannot be explained deterministically, and it cannot be predicted because it is chaotic. History (and also politics) is a ‘level two’ chaotic system: the system reacts to predictions about it.
There is no proof that history is working for the benefit of humans because we lack an objective scale on which to measure such benefit. Ever more scholars see cultures as a kind of mental infection or parasite, with humans as its unwitting host. Like evolution, history disregards the happiness of individual organisms.
The Scientific Revolution
The last 500 years have witnessed a phenomenal and unprecedented growth in human power. Prior to the sixteenth century, no human had circumnavigated the earth. Today anyone with a middle-class income can do this in just forty-eight hours. In 1500, humans were confined to the earth’s surface. On 20 July 1969 humans landed on the moon. In 1674 for the first time a human eye saw a microorganism. On 16 July 1945 the first atomic bomb was detonated in New Mexico, giving humankind the capability to end history.
Modern science assumes that we don’t know everything, and accepts that things we think we know may be wrong. Science aims to obtain new knowledge, and uses this knowledge to develop new technologies. The willingness to admit ignorance has made modern science more dynamic, supple and inquisitive than any previous tradition of knowledge.
Attempts to stabilise the socio-political order rely on two unscientific methods: to declare that a certain scientific theory is the final and absolute truth, or to live in accordance with a non-scientific absolute truth. Belief in technology and in the methods of scientific research has replaced to some extent the belief in absolute truths. Scientific research methods are based on collecting empirical observations, and putting them together using mathematical tools. Probabilistic models have become central to the social and natural sciences.
The real test of ‘knowledge’ is not whether it is true, but whether it empowers us. As science began to solve unsolvable problems, many became convinced that humankind could overcome all problems by acquiring and applying new knowledge. The leading project of the Scientific Revolution is to give humankind eternal life. Pills, injections and operations nowadays save us from a spate of illnesses and injuries.
Science is very expensive. Most scientific studies are funded because somebody believes they can help attain some political, economic or religious goal. The ideology justifies the cost of the research. The feedback loop between science, empire and capital has been history’s chief engine for the past 500 years.
The Scientific Revolution and European imperialism were inseparable. At the end of the fifteenth century Europe became a hothouse of important military, political, economic and cultural developments. How did the inhabitants of Europe manage to break out of their remote corner of the globe and conquer the entire world? Why did the military-industrial-scientific complex blossom in Europe rather than India? Europeans were used to thinking and behaving in a scientific and capitalist way. When the technological bonanza began, Europeans could harness it far better than anybody else.
Modern science flourished in and thanks to European empires. No other scientific tradition produced anything that comes even close to Newtonian physics or Darwinian biology. The key factor was that botanists and naval officers shared a similar mindset: they admitted their ignorance, felt compelled to go out and make new discoveries, and hoped new knowledge would make them masters of the world.
The discovery of America was the foundational event of the Scientific Revolution. It taught Europeans to favour present observations over past traditions, and obliged them to search at breakneck speed for new knowledge that was needed to control the vast new territories. European scholars began to admit that there were important things they did not know. European expeditions created a network of bases all over the world, thus creating the history of a single integrated human society. What made Europeans exceptional was their insatiable ambition to explore and conquer. Only in the twentieth century did non-European cultures adopt a truly global vision. This was one of the crucial factors that led to the collapse of European hegemony.
Modern science and modern empires were motivated by the restless feeling that perhaps something important awaited beyond the horizon. For modern Europeans, building an empire was a scientific project, while setting up a scientific discipline was an imperial project. Linguistics received enthusiast imperial support. The European empires believed that in order to govern effectively they must know the languages and cultures of their subjects. The production of a constant stream of new knowledge gave the empires ideological justification. Imperialists claimed that their empires were altruistic projects conducted for the sake of the non-European races. Of course, the facts often belied this myth. Empires created the world as we know it, including the ideologies we use in order to judge them. Behind the meteoric rise of both science and empire lurks on particularly important force: capitalism.
To understand modern economic history, you need to understand what accounts for its growth. Banks are allowed to lend ten dollars for every dollar they actually possess. Our trust in the imaginary future enables banks to flourish. This trust is the sole backing for most of the money in the world. Credit enables us to build the present at the expense of the future. It’s founded on the assumption that our future resources are sure to be far more abundant than our present resources.
The Scientific Revolution introduced the idea of progress, which soon was translated into believing that the sum total of human production, trade and wealth could be increased. In 1776 Adam Smith made the innovative argument that an increase in the profits of private entrepreneurs is the basis for the increase in collective wealth and prosperity. Egoism is altruism. The most sacred commandment in the new capitalist creed is: ‘The profits of production must be reinvested in increasing production.’ The principal tenet of capitalism is that economic growth is the supreme good.
Over the last few years, banks and governments have been frenziedly printing money, hoping that the scientists and technicians will manage to come up with something really big, before the bubble bursts. If the labs do not fulfil these expectations in time, we are heading towards very rough times.
It was European imperialism that created the capitalist credit system. Explorations were a very risky and costly business. To increase the number of investors and reduce the risk they incurred, Europeans turned to limited liability joint-stock companies. By letting the rule of law prevail and respecting private property, the Dutch managed to raise sufficient credit to replace the Spaniards and Portuguese as masters of the ocean highways. The most famous Dutch joint-stock company, the VOC, financed the conquest of Indonesia. After the decline of the Dutch Empire, the British Empire was established and run largely by private joint-stock companies.
During the nineteenth century the connection between joint-stock companies and governments grew stronger: the state started looking after the interests of the companies. Today a country’s credit rating is far more important to its economic well-being than are its natural resources. The most important economic resource is trust in the future, and this resource is constantly threatened by thieves and charlatans. It is the job of political systems to ensure trust by legislating sanctions and enforcing the law.
In a completely free market, avaricious capitalists can collude against their workers and might curtail their freedom of movement through debt peonage or slavery. The rise of European capitalism went hand in hand with the rise of the Atlantic slave trade. Unrestrained market forces were responsible for this calamity. Free-market capitalism cannot ensure that profits are gained in a fair way, or distributed in a fair manner. Capitalism has killed millions out of cold indifference coupled with greed. Much like the Agricultural Revolution, so too the growth of the modern economy might turn out to be a colossal fraud, with many more individuals living in hunger and want. We may not like capitalism, but we cannot live without it.
Almost everything people did throughout history was fuelled by solar energy that was captured by plants and converted into muscle power. The most important invention in the history of energy production is the steam engine, which converts heat into movement. At heart, the Industrial Revolution has been a revolution in energy conversion. The amount of energy stored in all the fossil fuel on earth is negligible compared to the amount that the sun dispenses every day. As humans worked out how to harness large quantities of cheap energy, they could begin exploiting previously inaccessible deposits of raw materials. Scientific breakthroughs enabled humankind to invent and discover completely new raw materials.
During the last 200 years, industrial production methods became the mainstay of agriculture. Farm animals stopped being viewed as living creatures and came to be treated as machines. A need shaped in the wild continues to be felt subjectively even if it is no longer really necessary for survival and reproduction. The modern capitalist economy must constantly increase production if it is to survive. Consumerism has worked very hard to convince people that indulgence is good for you.
Traditional agriculture depended on cycles of natural time and organic growth. Modern industry sanctifies precision and uniformity. Today, a single affluent family generally has more timepieces at home than an entire medieval country. Almost everything we do has to be done on time.
From the earliest times humans lived in small, intimate communities, most of whose members were kin. Village life involved many transactions but few payments. A person who lost his or her family and community around 1750 was as good as dead. The Industrial Revolution brought about the collapse of the family and the local community and their replacement by the state and the market. ‘Become individuals,’ the state and market said, ‘we will take care of you.’ The state and the market are the mother of the individual, and the individual can survive only thanks to them. Many bewail the lost of strong families and feel alienated and threatened by the power of the impersonal state and market. Youngsters are increasingly excused from obeying their elders, whereas parents are blamed for anything that goes wrong in the life of their child.
Markets and states foster imagined communities of people who don’t really know each other, but imagine that they do. The two most important examples are the nation and the consumer tribes.
Most people don’t appreciate just how peaceful an era we live in. The decline of violence is due largely to the rise of the state. International violence has dropped to an all-time low. Wars are no longer the norm. Real peace is the implausibility of war. Nuclear weapons have turned war between superpowers into collective suicide. Foreign trade and investments have become all-important. The tightening web of international connections erodes the independence of most countries.
Did the wealth humankind accumulated over the last five centuries translate into new-found contentment? Money brings happiness up to a point, and beyond that point is has little significance. Illness that doesn’t get worse decreases happiness only in the short term because people adjust to their new condition. Family and community seem to have more impact on our happiness than money and health. Happiness depends on the correlation between objective conditions and subjective expectations. Being satisfied with what you already have is far more important than getting more of what you want. It is all a matter of expectations.
Our internal biochemical system seems to be programmed to keep happiness levels relatively constant. The set point of this system differs from person to person. Most historical events have had no impact on our biochemistry. Happiness begins within.
Happiness consists in seeing one’s life in its entirety as meaningful and worthwhile. As Nietzsche put it, if you have a why to live, you can bear almost any how. As far as we can tell, from a purely scientific viewpoint, human life has absolutely no meaning. Any meaning that people ascribe to their lives is just a delusion.
According to the selfish gene theory, natural selection makes people choose what is good for the reproduction of their genes, even if it is bad for them as individuals. According to Buddhism people are liberated from suffering when they understand the impermanent nature of all their feelings, and stop craving them. According to Buddha happiness is independent from external conditions and also independent of our inner feelings.
Homo sapiens is beginning to break the laws of natural selection, replacing them with the laws of intelligent design. In laboratories throughout the world, scientists are engineering living beings.
The prevailing feeling is that our ability to modify genes is outpacing our capacity for making wise and far-sighted use of the skill. Genetic engineering might enable us to make far-reaching alterations to our physiology, and our intellectual and emotional capacities. Perhaps this would transform Homo sapiens into something altogether different.
We stand poised on the brink of becoming cyborgs, of having inorganic features that are inseparable from our bodies, features that modify our abilities, desires, personalities and identities.
Our ability to engineer not merely the world around us, but above all the world inside our bodies and minds, is developing at breakneck speed. The real potential of future technologies is to change Homo sapiens itself, including our emotions and desires. The future masters of the world will probably be more different from us than we are from Neanderthals.
History teaches us that what seems to be just around the corner may never materialise due to unforeseen barriers, and that other unimagined scenarios will in fact come to pass. The only thing we can try to do is to influence the direction scientists are taking: What do we want to want?
Unfortunately, the Sapiens regime on earth has so far produced little that we can be proud of. We remain unsure of our goals and we seem to be as discontented as ever. We are more powerful than ever before, but have little idea what to do with all that power. Worse still, humans seem to be more irresponsible than ever. Is there anything more dangerous than dissatisfied and irresponsible gods who don’t know what they want?