Sapiens - critical summary review

According to Israeli historian Yuval Noah Harari, three important revolutions shaped the course of human history: the Cognitive Revolution, which kick-started history about 70,000 years ago; the Agricultural Revolution, which sped it up about 12,000 years ago; and the Scientific Revolution, which, having started just half a millennium ago, may as well end it in the very recent future. “Sapiens” tells “the story of how these three revolutions have affected humans and their fellow organisms.” Get ready to hear all about it!

An animal with no significance

About 6 million years ago, a female ape had two daughters; the first one became the ancestor of all chimpanzees, and the second one – the grandmother of all modern humans. In other words, we are nothing more but just another species of animals belonging to the family of great apes; biologically speaking, chimpanzees, gorillas, and orangutans are our cousins. 

As we discovered just recently, we keep an even more disturbing skeleton in the closet of our history. Namely, in addition to an abundance of uncivilized cousins, once upon a time we had quite a few brothers and sisters as well. More precisely, from about 2 million years ago and until around 10,000 years ago, the world was home to at least six different human species. Just like there are polar bears and grizzly bears today, some time ago, besides us, there were also Homo neanderthalensis (in Europe and Western Asia), Homo erectus (in East Asia), Homo denisova (in Siberia), as well as Homo soloensis and Homo floresiensis (both on the islands of Indonesia).

All of these humans first evolved in East Africa about 2.5 million years from an earlier genus of apes called Australopithecus, which means “Southern ape.” Some of them eventually migrated away from their homeland and settled on different continents. The process of adaptation in different climates through the following millions of years resulted in the inevitable speciation, and around 300,000 years ago, our species, Homo sapiens – referred by the author as the titular “Sapiens” –  finally appeared somewhere in Africa.

But there was nothing special about this new species. The most important thing to know about them, writes Harari, is that “they were insignificant animals with no more impact on their environment than gorillas, fireflies or jellyfish.” In fact, up until 70,000 years ago, Homo sapiens wasn’t even the most advanced of the six human species: Homo neanderthalensis – popularly referred to simply as ‘Neanderthals’ – were bulkier, more muscular, had larger brains and discovered fire long before us. And yet, they were wiped away from the books of history, and we evolved to be able to write them. Now, how did that happen?

The Cognitive Revolution

Believe it or not, it was a matter of pure chance. About 70,000 years ago, “accidental genetic mutations changed the inner wiring of the brains of Sapiens, enabling them to think in unprecedented ways and to communicate using an altogether new type of language.” We don’t know why this mutation – referred by Harari as the “Tree of Knowledge mutation” – occurred in Sapiens DNA rather than that of Neanderthals. But we do know that, thanks to it, Sapiens went through something historians call the Cognitive Revolution and walked out of it as the sole human species on Earth and the planet’s undisputed ruler.

It all began with the appearance of Sapiens language. There were many other languages before it – both animal and human – but unlike them, ours was amazingly supple – owing to the accidental rewiring of our brains. A green monkey could only say to its comrades, “Careful! A lion!”, but our predecessors could describe the lion’s exact location, the paths leading to the area, and the different ways to deal with it. As a result, humans could plan complex actions and carry them out as cohesive units.

Even more importantly, due to the flexibility of language, early humans could gossip about each other. “Social cooperation is our key for survival and reproduction,” comments Harari. “It is not enough for individual men and women to know the whereabouts of lions and bison. It’s much more important for them to know who in their band hates whom, who is sleeping with whom, who is honest, and who is a cheat.” Language, in other words, evolved as a way of gossiping, and gossiping helped humans form larger and larger coalitions of mutually trusting members.

However, the truly unique feature of human language wasn’t its ability to transmit information about lions or other humans – but its ability to transfer information about nonexistent things, like gods and nations. Most people can’t intimately know more than 150 human beings, so, even with the help of gossiping, early modern humans couldn’t create larger groups than that. 

“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,” writes Harari. “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.”

The Agricultural Revolution

The ability to create collective fictions and speak about them is one of the unique traits of modern humans. It may be the most important difference between us and our cousins, the great apes. You can’t convince a monkey to give someone else a real banana by promising him limitless bananas in monkey heaven. And yet, you can convince millions of humans to sacrifice their lives for their country or their gods – even though neither exists in their absence. 

However, despite not being objective phenomena, gods and countries aren’t lies either – they are, instead, intersubjective realities that serve as links between the subjective consciousness of many people. And they are what allowed early modern humans to collaborate flexibly in unprecedently large numbers and with countless strangers. You know only a small percentage of the millions of individuals who call themselves your compatriots, but you consider all of them “your people” because you believe – just like they do – in the existence of your shared nation, homeland, and flag. Still, these are all abstract formations, social constructs, imagined realities. If people stopped believing in them, they would stop existing.

The ability to transmit information about things that aren’t real – tribal spirits, nations, or human rights – allowed early modern humans not only to cooperate on a larger scale but also to rapidly innovate their social behavior and conquer the world. They migrated from East Africa to Eurasia and either interbred with the Neanderthals or – more likely – conducted “the first and most significant ethnic-cleansing campaign in history.” 

Either way, around 30,000 years ago, Neanderthals disappeared completely from history, and, in the ensuing millennia, the same happened to all the other human species. Around 13,000 years ago, after the extinction of Homo floresiensis – a dwarfish, hobbitlike type of archaic humans – Homo sapiens became the only surviving human species.

Not long after, in the hilly regions of the Middle East, modern humans started devoting most of their time and effort to manipulating the lives of a few animal and plant species. This commitment set off the Agricultural Revolution, which, in just ten thousand years, converted almost all humans from hunter-gatherers into farmers, resulting in the creation of the first settlements, a substantial increase in the food supply, and extraordinary population growth. 

However, the Agricultural Revolution was a trap – and probably history’s greatest. In retrospect, it made the lives of most individuals worse than they had been when humans were mostly hunter-gatherers. True, there was extra food, but it mostly ended amongst the elite; both the diet and the daily lives of the majority of our predecessors became significantly less varied once they chose to replace foraging with farming. The average farmer worked harder than the average forager – and got a worse diet in return. 

However, as a species, humanity progressed: because of agriculture, humans started creating larger collectives and growing ever more powerful in relation to all other animals. In a nutshell, the story of the Agricultural Revolution is pretty much a story of groups trading off individual pleasure for collective strength. Not consciously, of course, but in terms of results – it hardly makes a difference.

The unification of humankind

As human societies grew larger and more complex, so did their collective fictions. This resulted in a “memory overload” problem. For millions of years, people could store all the necessary information in a single place: their brain. However, as “empire-sized databases” started to appear – encompassing everything from myths through symbols to numbers – the human brain stopped being a good storage device.

This problem was first overcome in Mesopotamia – present-day Iraq and Syria. There, sometime during the 4th millennium B.C., “some unknown Sumerian geniuses invented a system for storing and processing information outside their brains, one that was custom-built to handle large amounts of mathematical data.” Nowadays, we refer to this data-processing system invented by the Sumerians as “writing.”

Interestingly, as Harari writes, “the first texts of history contain no philosophical insights, no poetry, legends, laws, or even royal triumphs. They are humdrum economic documents, recording the payment of taxes, the accumulation of debts, and the ownership of property.” In other words, writing developed as a means of storing complex financial transactions; interest in using the same data-processing system to store information about gods and emperors appeared only later.

But it did inevitably appear – and it made a lasting impression. Because the emergence of money, religion, and empires, somewhat surprisingly, pushed humankind in the direction of global unification. These three are all seen as pretty divisive nowadays, but without them, we might have never bridged the gap between “us” and “them.” 

Just like all other social mammals, Sapiens are xenophobic creatures by design and, up until the 1st millennium B.C., nobody imagined “the entire world and the entire human race as a single unit governed by a single set of laws.” But then, merchants, conquerors, and prophets appeared – “the first people who managed to transcend the binary evolutionary division, ‘us vs them’, and to foresee the potential unity of humankind.”

“For the merchants,” writes Harari, “the entire world was a single market and all humans were potential customers. They tried to establish an economic order that would apply to all, everywhere. For the conquerors, the entire world was a single empire and all humans were potential subjects; and for the prophets, the entire world held a single truth and all humans were potential believers. They too tried to establish an order that would be applicable for everyone everywhere.”

The Scientific Revolution

Establishing universal orders – whether monetary, religious, or imperial – is not easy: it requires a lot of research, power, and resources. Over time, these three combined in a highly efficient feedback loop that, in Renaissance Europe, gave birth to the last of the three great human revolutions: the Scientific.

We tend to think of scientific progress as something noble and unprejudiced, but we ignore the fact that it never occurs in a random direction – but in the direction determined by the beliefs of those who fund it. Without resources, scientific research is almost impossible, and the institutions providing them – whether governments or corporations – expect to have their powers increased (not diminished) by the subsequent discoveries and findings. With greater power comes access to newer and better resources, and some of these are reinvested in further research and development. 

Generally speaking, this feedback loop is much older than the Scientific Revolution: humans have sought to understand the universe at least since their cognitive leap 70,000 years ago. But the last five centuries have witnessed unprecedented growth in human power and quality of life. Just for comparison, in the year 1500, there were only about half a million people in the entire world; today, there are over 7 billion. Back then, 150 out of 1,000 newborns died during their first year; today, only 7 out of 1,000 children die before the age of 15. So, what changed in the meantime to allow for the Scientific Revolution?

Harari argues that modern science differs from all previous traditions of knowledge in three critical ways: the willingness to admit ignorance, the centrality of observation and mathematics, and the acquisition of new powers. The first of the three is, perhaps, most important. “The Scientific Revolution has not been a revolution of knowledge,” remarks Harari in view of this. “It has been, above all, a revolution of ignorance. The great discovery that launched the Scientific Revolution was the discovery that humans do not know the answers to their most important questions.”

What lies ahead

Science and exploration turned some countries into continent-spanning empires, and some political and economic doctrines into secular, natural-law religions – such as communism, Nazism, nationalism, liberalism, and capitalism. Of these five, the last two have been by far the most successful. 

Working hand in hand with science, they gave us more functional institutions, inalienable rights, a better-connected world, and the most prosperous era of history – but also privacy issues, economic inequality, numerous genocides, two devastating world wars, and, finally, the nuclear bomb. Harari describes its detonation in 1945 as “the single most remarkable and defining moment of the past 500 years,” noting that, “from that point forward, humankind had the capability not only to change the course of history, but to end it.”

Interestingly, this caused one final and utterly unexpected tectonic shift in global political cultures. Throughout history – whether Hun chieftains, Viking noblemen, or Aztec priests – most ruling elites viewed war as a positive good. Today’s elites, however – whether American politicians, Japanese businessmen, Russian intellectuals, or Chinese artists – genuinely see war as both evil and avoidable. They have to: most of the time, their livelihood and prosperity depend upon it. Up until recently, the Scientific Revolution risked to be remembered by subsequent generations as an age of unmatched bloodshed and mindless slaughter; nowadays, it seems more likely that it will be remembered as an age of peace and affluence.

However, Harari warns that “may” isn’t the same as “will”: true, we’re on the verge of evolving into Homo deus – godlike people capable of creating other species – but the same technology means that one small mistake or misunderstanding could result in the end of humanity. “We are on the threshold of both heaven and hell, moving nervously between the gateway of the one and the anteroom of the other,” concludes Harari. “History has still not decided where we will end up, and a string of coincidences might yet send us rolling in either direction.”

Final Notes

“Sapiens” may not offer some new contributions to scholarship, but there’s a lot of value in repackaging and rearranging past knowledge into easily digestible, broad-viewed popular science books. It allows us to see the big picture, the forest through the trees.

That’s why the book was voted “one of the ten best brainy books of the decade” by The Guardian, translated into 45 languages, sold in millions of copies, and recommended by everyone, from Bill Gates to Mark Zuckerberg. That’s why you should read it as soon as possible.

12min Tip

You are Homo sapiens, the “wise man,” the apex predator, the most exceptional primate in existence. Be simultaneously proud and humble in this knowledge.