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Sapiens provides a scientific perspective on the history of humans through three revolutions. Yuval Noah Harari begins the book with our cognitive revolution, which occurred 70,000 years ago. Then, he describes our agricultural revolution of 12,000 years ago. Finally, he outlines the scientific revolution of 500 years ago. These three revolutions have shaped the humans we are today and the planet we inhabit.

About the Book

Sapiens has been incredibly popular since being published in English in 2014. The book is based on a lecture series that Yuval previously taught at the Hebrew University of Jerusalem. Sapiens made it onto the New York Times best-seller list. Also, the book won the National Library of China’s Wenjin Book Award for the best book published in 2014. Bill Gates has also ranked Sapiens among his ten favorite books. The book has now been translated into 45 languages.

About Yuval Noah Harari

Yuval Noah Harari is an Israeli public intellectual and historian. He is currently a professor in the Department of History at the Hebrew University of Jerusalem. He holds a Ph.D. from Jesus College, Oxford. Sapiens was Yuval’s breakthrough work. He has since published two more books: Homo Deus and 21 Lessons for the 21st Century.

Humans in Their First Form

Humans first appeared about 2.5 million years ago in a part of East Africa. The most relevant species to modern humans is Homo Erectus. Homo Erectus is an extinct species of archaic humans. Upon traveling from East Africa to other parts of the world, Homo Erectus evolved into multiple forms of homo, such as Neanderthalensis in Asia. It is not until 300,000 years ago that modern humans emerged, or Homo Sapiens. 

What separated Homo Sapiens from the other species within the Homo genus is our large brains. Homo Sapiens also have an unusually high energy expenditure associated with their brain. The Homo Sapien brain consumes 25% of energy at rest, while the norm for other apes is 8%.

We utilized our brainpower to create sharp tools and develop complex social networks. Homo Sapiens evolved as social animals based on the long gestation period for children. A child taking a long time to raise suggests that Homo Sapiens are adapted for developing strong social ties.

Homo Sapiens’ use of fire was also fundamental to its survival. Carefully managed fires were not only used for clearing forests, but also for cooking food. Fire allowed Homo Sapiens to eat food that was far easier to digest. Easily digestible food is an essential feature of Homo Sapiens’ survival. Food that is hard to digest requires long intestines. However, both long intestines and large brains are energy drains. Therefore, cooking food allowed Homo Sapiens to develop shortened intestines and utilize the excess energy to grow their brains further.

Neanderthals had already learned to use fire long before the emergence of Homo Sapiens, but they eventually died out. There are two main theories why Homo Sapiens prospered, and other Homo Species did not:

The Interbreeding Theory

Homo Sapiens started coming across other Homo species, such as Homo Neanderthalensis. Hence, this resulted in the species gradually emerging together. This theory is supported by DNA evidence. Even today, modern Europeans seem to contain Neanderthal DNA. 

The Replacement Theory

“Tolerance is not a Sapiens trademark. In modern times, a small difference in skin colour, dialect or religion has been enough to prompt one group of Sapiens to set about exterminating another group. Would ancient Sapiens have been more tolerant towards an entirely different human species? It may well be that when Sapiens encountered Neanderthals, the result was the first and most significant ethnic-cleansing campaign in history.”

– Yuval Noah Harari

The replacement theory suggests that Homo Sapiens pushed other species out. As Homo Sapiens had superior skills and technology (tools), they were able to push other Homo species toward extinction. This could have been by stealing food or through more violent means. 

Both Might Be Correct

Yuval explains that it is most likely that both of these occurred. A combination of interbreeding and replacement allowed Homo Sapiens to develop communication skills and conquer the globe. 

The Cognitive Revolution

As previously mentioned, what made Homo Sapiens unique was the structure of their brains. Yuval describes the period where a significant leap in brain evolution occurred as the cognitive revolution. This period supposedly occurred approximately 70,000 years ago. The Cognitive Revolution involved the development of far more sophisticated communities. Plus, the development of hunting based on more advanced techniques and tools. 

As expected, with the development of communities and hunting practices came the first recognizable examples of trade networks. These trade networks were primitive but meant that more Homo Sapiens could have access to food and resources. 

More significant movement by Homo Sapiens also characterized the Cognitive Revolution. Using their super brain power, Homo Sapiens created snowshoes and warm clothing out of skin and hair. These clothes allowed Homo Sapiens to inhabit cooler parts of the world, such as America and the Arctic. Unlike other Homo Species, Homo Sapiens were, therefore, able to find food and resources in even the harshest environments. Yuval provides an example of these skills in action. Homo Sapiens would have had to withstand the cold temperatures of the Siberian passage to inhabit America. Therefore, they must have learned to team together to hunt large mammoths for food. Plus, they created clothing that would prevent them from freezing to death. 

Homo Sapiens Have Always Encouraged Extinction

“The romantic contrast between modern industry that “destroys nature” and our ancestors who “lived in harmony with nature” is groundless. Long before the Industrial Revolution, Homo sapiens held the record among all organisms for driving the most plant and animal species to their extinctions. We have the dubious distinction of being the deadliest species in the annals of life.”

– Yuval Noah Harari

In the modern world, extinctions are a widespread issue. However, this is not purely a modern phenomenon. Instead, the development of hunting techniques in Homo Sapiens led to a trail of extinctions. Just 50,000 years ago, Homo Sapiens would have inhabited the same land as 20-foot tall Sloths and Armadillos the size of cars. However, within a couple of thousand years of Homo Sapiens’ existence the vast majority of these animals had been pushed to extinction. 23 out of 24 species larger than 50 Kg became extinct within a few thousand years of Homo Sapiens travelling to Australia. The marsupials, mammals with baby-carrying pouches, failed to adapt to the onslaught of the humans. Similarly, in America, Mammoths, Mastodons, and many other native animals faltered under the influence of Homo Sapiens’ pressure. The same story has been repeated wherever Homo Sapiens go. 

In this book, Yuval explains that there have been three main extinctions related to Homo Sapiens’ development. First wave extinction occurred when Homo Sapiens were hunter-gatherers, and they first entered new ecosystems. The second wave extinction occurred when Homo Sapiens became farmers. Farming was associated with the burning of forests and grasslands to grow crops. Finally, the third wave extinction is the Industrial Revolution. 

The Industrial Revolution started in the 18th century and still takes place today. The invention of the steam engine and electricity freed us from our day-night and winter-summer cycle. We can now work and produce whenever we want. Production has been increased considerably by electricity. The invention of electricity encouraged consumerism. We can now create so much produce that a mentality around buying things is needed. Historically, religion has generally encouraged austerity. In the modern world, we accept consumerism and encourage consumption for the sake of consumption. Capitalism wins twice with overconsumption. As a society, we over-consume food, alcohol, and cigarettes. Capitalists in the form of pharmaceutical companies, diet fads, and private healthcare sell you the ‘cure’ to your overconsumption. 

“The capitalist and consumerist ethics are two sides of the same coin, a merger of two commandments. The supreme commandment of the rich is ‘Invest!’ The supreme commandment of the rest of us is ‘Buy!’ The capitalist–consumerist ethic is revolutionary in another respect. Most previous ethical systems presented people with a pretty tough deal. They were promised paradise, but only if they cultivated compassion and tolerance, overcame craving and anger, and restrained their selfish interests. This was too tough for most. The history of ethics is a sad tale of wonderful ideals that nobody can live up to. Most Christians did not imitate Christ, most Buddhists failed to follow Buddha, and most Confucians would have caused Confucius a temper tantrum. In contrast, most people today successfully live up to the capitalist–consumerist ideal. The new ethic promises paradise on condition that the rich remain greedy and spend their time making more money and that the masses give free reign to their cravings and passions and buy more and more. This is the first religion in history whose followers actually do what they are asked to do. How though do we know that we’ll really get paradise in return? We’ve seen it on television.”

– Yuval Noah Harari

Complex Language Helped Homo Sapiens to Thrive

“You could never convince a monkey to give you a banana by promising him limitless bananas after death, in monkey heaven. Only Sapiens can believe such fictions. But why is it important? […] Fiction is of immense importance because it enabled us to imagine things collectively. We can weave common myths such as the biblical creation story, the Dreamtime myths of Aboriginal Australians, and the nationalist myths of modern states. And it is these myths that enable Sapiens alone to cooperate flexibly with thousands and even millions of complete strangers.”

– Yuval Noah Harari

The reason that is often given for human superiority is our complex language. This same complex language is what helped Homo Sapiens to survive and thrive. The development of a complex language facilitated the spreading of information. Homo Sapiens were able to advise each other on how to hunt and distribute food. It also allowed Homo Sapiens to develop complex responses to threat e.g., the danger of predators. However, arguably the most critical impact of language development was gossip. Language facilitated Homo Sapiens in creating and believing in myths. These myths helped larger numbers of Homo Sapiens to collaborate and cooperate regarding a common understanding. These myths still unite us today: 

  • Religion is a myth
  • Nation-states are myths
  • Limited-liability corporation is a myth
  • The US declaration of independence is a myth

They are all figments of our imagination. Yuval explains that we laugh at the primitive myths of early Homo Sapiens. Yet, we are still connected and collaborate based on similar non-physical entities. 

“Christianity, capitalism, democracy, all are imagined orders with a large number of believers.”

– Yuval Noah Harari

Each of these benefits was highly important for Homo Sapiens’ domination. This domination would have been won by forming more substantial groups. Neanderthals would have beaten Sapiens in one-to-one combat. However, Yuval points out that the most critical benefit of complex communication is the sense of community it creates. Shared understanding between members of a group is relatively unique. Although animals like bees work together towards a common goal, the level of understanding is seemingly less detailed. The understanding between Homo Sapiens was more fluid than other animals, allowing Homo Sapiens to adapt their social structure based on changes in the environment. 

The Agricultural Revolution

Language was hugely influential in the development of small communities. However, it is agriculture that helped these communities grow into the global society we see today. To become a global society, Homo Sapiens had to transition from foragers to farmers. 

The vast majority of Homo Sapiens’ history has been spent in a nomadic lifestyle. Homo Sapiens would not settle in one area as they were always tracking prey and looking to forage for food. Therefore, they just traveled to places where food was plentiful and stayed there until they had to find more food. However, approximately 12,000 years ago, this lifestyle changed. The start of the Agricultural Revolution was a shift from finding food to creating food. 

There were many benefits to hunting and foraging instead of farming. Firstly, a hunter-gatherer may only have to spend a few hours a day collecting enough food. In comparison, the farmer has to work all day on the fields to produce a bountiful harvest. Plus, the food that a farmer during that time could harvest would have been wheat. Wheat was hard to digest and lacking nutrients. Despite this, wheat went from an unknown crop to a crop spread everywhere on the planet. 

Homo Sapiens were not designed for agriculture and farming. Wheat demanded protection from pests and animals, but Homo Sapiens were not initially adapted to meeting these demands. This begs the question, ‘why did Homo Sapiens start to farm?’ Historians suggest that the change to agriculture was a slow, gradual process. With each generation, the process became more societally ingrained. On top of this, as farmers multiplied, they cleared more land that had previously been used by foragers. This started to make agriculture a necessity, and foraging no longer a viable option. 

Agriculture did have one major advantage: efficiency. Once Homo Sapiens had learned how to farm edible plants that were nutrient-rich, it was possible to increase food supply significantly. You could grow large amounts of food in minimal areas. After perfecting this, Homo Sapiens started to domesticate animals. Homo Sapiens started by slaughtering the most aggressive and weak animals first. Then, as animals became more domesticated, they became more economically viable as a food product. 

“Domesticated chickens and cattle may well be an evolutionary success story, but they are also among the most miserable creatures that ever lived. The domestication of animals was founded on a series of brutal practices that only became crueler with the passing of the centuries.”

– Yuval Noah Harari

The symptom of high food supply was a significant increase in Homo Sapiens’ population. The Agricultural Revolution led to permanent settlements, which ultimately facilitated the conception of more children. Plus, the agricultural revolution encouraged Homo Sapiens to specialize in different fields. Individual Homo Sapiens no longer had to search for their food. Instead, they could become blacksmiths or weavers and trade these items for food. 

Issues arose when a surplus of food and commodities could be made. Food was integral, but eventually, the farmer would have enough knives or winter coats. The bargaining chip for other specialisms became less useful. The solution to this problem was money. 

Money Helped Solve the Problem of Surplus

“Money is the most universal and most efficient system of mutual trust ever devised.”

– Yuval Noah Harari

Based on this issue of surplus, approximately 5,000 years ago, money and writing were developed. Yuval explains that the first civilization to start using money in society were the Sumerians of Mesopotamia. In modern terms, Mesopotamia includes parts of Iraq, Syria, Turkey, and Kuwait. This society also started using clay tablets for etching people’s transactions using the simplest of economic symbols. Therefore, coins and gold were used as a currency, while the development of writing was integral for preventing corruption. Money helped create a central mechanism so that every seller knows the price of a good in a single currency. This approach helped the economy remain stable for a while. Yuval points out that, just like religion, money is a myth that we created and still utilize today. Anything can be used as a currency, as long as it is easy to transport, store, and has a wide enough acceptance. For example, Yuval uses the example of cigarettes being used as currency in Nazi concentration camps. 

The development of writing was also integral as Homo Sapiens’ memories are limited. Only a certain amount of information could (and still can be) stored by Homo Sapiens. 

As societies continued to grow, things became more complicated.

Laws Helped Regulate Money

As societies became larger and more complex, it became essential to develop economic laws. These laws required systems of authority, such as Kings or Emperors. Although modern societies view these authority figures as cruel, Yuval explains that they provided Homo Sapiens with political, social, and economic stability. 

Rulers, at this time, created their authority through religion. If people were willing to accept the ruler was placed there by Gods, they were far more willing to follow the ruler’s laws. Giving the example of Mesopotamia again, Yuval described how King Hammurabi was able to legitimize his laws by declaring that Gods had appointed him. Then, imperialism led to cultures becoming even larger. Diverse ethnicities and religious groups combined in society due to imperial campaigns. 

The Scientific Revolution

“The Scientific Revolution has not been a revolution of knowledge. 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. Premodern traditions of knowledge such as Islam, Christianity, Buddhism and Confucianism asserted that everything that is important to know about the world was already known. The great gods, or the one almighty God, or the wise people of the past possessed all-encompassing wisdom, which they revealed to us in scriptures and oral traditions. Ordinary mortals gained knowledge by delving into these ancient texts and traditions and understanding them properly. It was inconceivable that the Bible, the Qur’an or the Vedas were missing out on a crucial secret of the universe – a secret that might yet be discovered by flesh-and-blood creatures.”

– Yuval Noah Harari

The Scientific Revolution is the revolution that modernized Homo Sapien societies. In Homo Sapiens’ past, there had been a belief in Gods. These Gods were out of our control, and this meant Homo Sapiens often followed blindly. However, the scientific revolution allowed all Homo Sapiens, even the ‘mortals,’ to develop our understanding of the world. Homo Sapiens started to consider how they could improve the world through science, rather than through praying. 

The scientific revolution was characterized by gigantic leaps in our understanding of medicine, astronomy, and physics. Focusing on experimentation and observation allowed us to hugely improve the wellbeing of the average Homo Sapien in society. For example, child mortality rates have dropped considerably. Thousands of years ago, even the wealthiest members of society would lose two or three children to premature deaths. Today, infant mortality worldwide is only 1 in every 1,000 children. 

In addition to benefiting Homo Sapiens’ health, the scientific revolution also developed how we viewed economies. European governments looked to explore new land through explorers such as Columbus. These explorations encouraged colonization and further connections being drawn between countries on a global level. These interactions allowed more complex forms of currency to be developed than silver and gold. However, it came at the cost of indigenous people’s lives. 

European imperialism and the Scientific Revolution underpin the capitalist society we live in today. European governments used the scientific method and exploration to enlarge their empires and increase their profits. One of the negative impacts of this, though, was pushing for a homogenous society. The UK’s colonies covered over half of the world at one point. Hence, local customs, cultures, and laws were pushed out. European norms and science were forced on these indigenous countries. The European’s empire may have long since finished, but other countries are still dealing with cultural inheritance. 

Globalization Is on the March

Because of our history and the development of technology, we are now all interconnected. The consequence is that Homo Sapiens have never been more peaceful. Wars are now very rarely fought over resources, as resources are in such abundance. 

Some challenge globalization and dislike the cultural diversity it creates. Despite this, there are multiple benefits to globalization. Modern nations depend on each other for prosperity, and there are trade links between almost all countries. This reliance on each other leads to a much lower risk of war. It is in a country’s best interest to maintain peace as their own country’s prosperity is now partly dependent on the prosperity of other countries. Yuval explains that these factors mean that no recognized independent nation has been conquered and eliminated since WWII in 1945. 

Yuval explains that the 20th century was the most peaceful century ever. Some might see this as surprising due to the two world wars. However, 30% of all adult males were the victim of murder during the hunter-gatherer era. This percentage is now roughly 7%. Science helped encourage people to obey laws that forbid murder and violence, which encouraged stable societies and economies. These societies can now work together on a globalized scale, which further encourages peace. 

We Still Have Lots to Do

Although we are currently living in the most peaceful time, we must also pay attention to potential sources of conflict. Climate change and water potentially becoming a scarcity could encourage violence. Hence, we must do what we can to prevent these disasters from occurring. 

Yuval considers whether our development and improvements in health, wealth, and knowledge have made us happier. Yuval thinks not. Although there might be more short-term rises in happiness or sadness in the modern world, our happiness levels hover around the same level as they have been for a while. 

On top of this, although societies might be slightly happier than historical societies, wealth is currently distributed to a small number of people. Indigenous people, women, and people of color have continued to be given fewer opportunities to benefit from the improvements we see in today’s world. 

Yuval describes happiness as when our delusions about the meaning of our life synchronize with the collective delusions. Hence, in the modern age, we are left unhappy when we see advertisements as they increase our subjective expectations. 

What Does the Future Hold?

Yuval concludes the book by thinking about Homo Sapiens’ future. As a species, we are currently testing our biological limits through considerable advances in technology and science. Biotechnology and Bionics could mean that humans live for far longer and in different capacities. For example, Jesse Sullivan lost both his arms. However, he has been provided with bionic arms that he can operate using his thoughts. Decades ago, Jesse would have had a considerably worse life than he does today. Concerning aging, scientists have found ways to double the life span of sea life through genetic engineering. With the speed at which technology is advancing, we could see humans living for considerably longer and aging far slower. 

If Homo Sapiens eventually develop a way to live forever, there is no doubt that we will grasp it. Yuval explains that by this point, we can no longer describe ourselves as Homo Sapiens. We will be a new species altogether. This is what Yuval covers in his next book, Homo Deus. The future species could be part Human and part God. 

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