Books - Read and Enjoyed

Sapiens - A Brief History of Humankind

Harper, 2014

Homo Deus - A Brief History about Tomorrow

Harvill Secker, 2015

by Yuval Noah Harari.


Harari is a great narrator and his subject is the grandest story of all. It commences 70 000 years ago with, what he calls, the cognitive revolution of Homo Sapiens, runs to the presence in his first book, and extends into the future as based on what we know of humankind and current trends. He excels in identifying the critical aspects for the long term development trends and, like a bold artist, he paints with a big brush long lines that usually hit the mark and make the reader see the big connections.

The cognitive revolution took place approximately 70 000 years ago. The core of the cognitive revolution was the development of inter-subjectivity, which is a group phenomena and denotes the creation of a reality that is not valid outside of the group, but for the members of that group it is as real as stones, elephants, hunger and gravity. Inter-subjectivity allows the creation of stories that bind the group together, allows it to synchronize activities and to collaborate with group members, that do not know each other intimately or even personally. Inter-subjective reality, mostly labeled as fiction, in Harari’s words,

enabled us not merely to imagine things, but to do so 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. Such myths give Sapiens the unprecedented ability to cooperate flexibly in large numbers. Ants and bees can also work together, but they do so in a very rigid manner and only with close relatives. […] Sapiens can cooperate in extremely flexible ways with countless numbers of strangers. That’s why Sapiens rules the world, whereas ants eat our leftovers and chimps are locked up in zoos and research laboratories.

Before the cognitive revolution Sapiens, not unlike its great ape cousins, could collaborate in small bands of extended family where the bonds were based on smell, touch and an intimate joint history of mutual dependencies. All individuals in the group knew each other well and trusted each other based on mutual credence and reciprocal favors.

The construction of an inter-subjective reality, mediated by language, allowed people to cooperate based on their believe in a common story.

The Cognitive Revolution is accordingly the point when history declared its independence from biology. Until the Cognitive Revolution, the doings of all human species belonged to the realm of biology […] From the Cognitive Revolution onwards, historical narratives replace biological theories as our primary means of explaining the development of Homo Sapiens. To understand the rise of Christianity or the French Revolution, it is not enough to comprehend the interaction of genes, hormons and organisms. It is necessary to take into account the interaction of ideas, images and fantasies as well.

Fueled by the ability to collaborate in large bands of hundreds of people, Sapiens went out of Africa and conquered the world from Europe to China and Australia. Everywhere its ascendance transformed the landscape, fauna and flora. Sapiens

drove to extinction all the other human species of the world, 90 per cent of the large animals of Australia, 75 per cent of the large mammals of America and about 50 per cent of all the large land mammals of the planet - and all before they planted the first wheat field, shaped the first metal tool, wrote the first text or struck the first coin.

According to Harari the ability to create inter-subjective reality has been a defining force in the formation of all societies up to the present day. As examples of common stories of inter-subjective realities that form the pillars of societies Harari names all modern religions, money, laws and the rule by law, and human rights. All these are social constructs that only work, because sufficiently many people believe in them. But once they have been accepted in a society, they are as real as any physical object and nobody can ignore them without suffering severe consequences. For instance, the property law of my country prohibits me to cut down my neighbor’s tree. That only works if sufficiently many people believe in it: my neighbor, the police, the judge, and the lawyers. If nobody believed in that law, it would be nil and I could freely cut down the tree with my chainsaw. Nobody would care except perhaps my neighbor. However, if everybody believes in a shared story of property ownership, borders, and law enforcement, I have no choice other than to accept this story. If I do not accept it, I would greatly suffer and gradually learn to abide by it.

A formative power for organizing societies and prescribing the way they work in minute detail comes with all these grand stories that Sapiens has invented: Religions, Armies, Gods, Kings, Money, Property, Laws, Markets, Companies, etc. Harari’s narrative talent not only brings to life how shared imagination facilitated the organization of ancient Mesopotamian states but also how our own modern societies crucially depend on fictional stories in economics, law and politics.


While the first book, Sapiens, extends from the cognitive revolution to the presence, Harari’s second book, Homo Deus starts with our present situation, analyzes the grand trends and speculates where this may lead us. The two books overlap in analyzing today’s human condition. Both look at the big picture, tell the grand, defining stories of humanity, and draw with astonishing accuracy the big lines that connect Sapien’s past with Deus’ future.

While the big stories of the past, as elaborated in Sapiens, have revolved around religion, where either the forces of nature (Buddhism, Greek and Roman religions, …), the forces of society (Konfuzianism, Philosophical schools about ethics, …) or a unified, abstracted god (Judaism, Christianity, Islam, …), have been in the center of the narrative, the central character of today’s and tomorrow’s story is Homo Sapiens itself. As expanded in Homo Deus, humanism is the great story of today, the modern religion. It has as central axiom the believe that it is the individual human or the collective of humans, that gives meaning to our world, that defines what is good and bad. Since the individual human experience is sacred, it is beyond questioning that the individual’s pleasure is good and pain is bad. Everything else follows from that. We organize our societies to minimize the pain and maximize the well-being of individuals. Pain and suffering of a person is only acceptable, either if it cannot be avoided, or if it minimizes other people’s suffering such that the net outcome is less suffering. It is due to Harari’s great talent as narrator to convincingly bring out that this is a premises of modern times and other ages have been far more indifferent to pleasure and pain of individuals.

Harari distinguishes three branches of the humanist religion, the liberal humanism, social humanism, and evolutionary humanism. The orthodox, liberal humanism

holds that each human being is a unique individual possessing a distinctive inner voice and a never-to-be-repeated series if experiences. Every human being is a singular ray of light that illuminates the world from a different perspective, and that adds color, depth and meaning to the universe. Hence we ought to give as much freedom as possible to every individual to experience the world, follow his or her inner voice and express his or her inner truth. Whether in politics, economics or art, individual free will should have far more weight than state interests or religious doctrines.

Social humanism contends that the main flaw of liberal humanism is that an individual’s self and feeling is not independent and unaltered by the environment but that it rather depends on and evolves in a social context. To understand an individual’s feeling, preferences and anxieties is only possible based on the social context, her social and family history, her peers, her schools and teachers. Thus if one really values the individual person, it is paramount to get the social context right, to provide for a caring society, to improve the educational system, and to fairly balance entitlements, obligations and responsibilities.

Evolutionary humanism, with the Nazis as best known proponents, has a different solution for the well fare of humans. Not social engineering can improve the human condition but an evolutionary process of competition and selection between individuals, nations and races will eventually lead to ever more improved humans. While the Nazi sect of evolutionary humanism has largely been discredited, the vision to continuously enhance and evolve the biological basis of humans may celebrate a come back in the form of bio- and genetic engineering. In fact, that is one of three tracks to enhance Sapiens to Homo Deus.

The upgrading of humans into gods may follow any of three paths: biological engineering, cyborg engineering and the engineering of non-organic beings.

The second half of Homo Deus explores these tracks of possible developments for future humans and techno-human societies. It also considers carefully the possibilities, that humans first loose control of and then value for a future society dominated by cyborgs and artificial intelligence. While still well narrated, this part of the book is less convincing because it offers more speculations then ingenious discernment. Harari is at his best as historian conveying deep insights and astute wisdom about the human history and condition.

As both books present a compelling story full of clear-sighted observations and vivid illustrations of grand connections, this review cannot do full justice to the many gems hidden within the 900 odd pages. For instance, the account of the agricultural revolution as the ``biggest fraud in history’’ is an unforgettable take-away for me. On one hand the fact that Sapiens can invent and enforce shared stories to form inter-subjective realities is, according to Harari, the basis of all cultural progress and development, the basis of all human societies. He gives examples where some stories won out over others, not because they are more accurate or a better match to reality, but because they were a better instrument to coordinate people’s actions. For instance,

Yet even though Horodotus and Thycidides understood reality much better then the authors of the Bible, when the two world views collided, the Bible won by a knock-out. The Greeks adopted the jewish view of history, rather than vice versa. A thousand years after Thucydides, the Greeks became convinced that if some barbarian horde invaded, surely it was divine punishmentr for their sins. No matter how mistaken the biblical world view was, it provided a better basis for large-scale human cooperation.

Only sometimes Harari gets carried away by his own storytelling and misses the necessary rigor and scrutiny. The notion of story is central to both books.


However, his is also a great story, presumably explaining the big developments of Homo Sapiens during the last 70000 years. So one wonders if his story is compelling because it closely matches reality and describes real causalities, or if it is a powerful illustration that appeals to the natural imagination of the reader. When reading the books, I wished at several points that Harari had scrutinized the essence of the power of stories, that he had studied and explained what distinguishes an amusing ferry tale without consequences from a powerfully culture forming story. To which degree are culture forming stories rooted in reality? What exactly makes one story winning over another? This additional level of scrutiny and rigor would have made his own story even more comprehensive, more compelling, and more useful.

A central hypothesis in Homo Deus is the framing of humanism as a religion, which is based on the assumptions of individualism and the individual’s free will. Harari is right to question the rational and scientific basis of these assumptions, but his treatment of the subject falls short of what would have been desirable given the overarching importance of this topic and those claims for the book.

First, Harari questions if it is correct and meaningful to talk about an individual. The individual, so the story of humanism goes, is the atomic agent of our liberal societies and of the subjective experiences of each of us. The individual person is the agent that has rights, obligations, citizenship, owns property, has responsibilities, is liable, can be punished and rewarded. If the individual as an acting, deciding, resource consuming, happiness pursuing agent does not exist, there is not much in the formational conventions of our societies that still makes sense. Harari throws into question the validity of the concept “individual” with evidence from clinical observations and neuro-science. His central argument rests on studies of split-brain patients. The human brain’s neocortex consists of two main parts, a left and a right hemisphere that are connected by massive bundles of neuron fibers forming communication highways, that exchange vast amounts of information and seem to play a key role in integrating the brains activity into one mind. In rare cases of epilepsy these communication bundles have been cut to suppress the hazardous distribution of chaotic epileptic activities through the brain. While containing the symptoms of epilepsy, in some patients the effect has been the emergence of two separate personalities who could be observed to behave differently. In intriguing experiments questions have been posed to the two separated hemispheres and different answers have been received. These experiments exploited the fact that the left hemisphere controls the right visual field and the right hand, while the right hemisphere controls the left visual field and the left hand. From these experiments and similar evidence Harari concludes that there is little point in talking about an atomic individual because obviously in every brain there are multiple cognitive processes that operate partially independently from each other and only generate the delusion of an indivisible individual person.

This argument seems shallow. An individual’s personality is an emergent system property of the whole brain that cannot be reduced to any of its parts. System properties disappear or are profoundly altered when the system is cut into smaller pieces. We know that the brain consists of many modular and concurrently active processes that cooperate, synchronize and communicate to produce thoroughly integrated behavior. Healthy humans never execute conflicting decisions and all basic activities such as walking, writing, talking, driving, playing, etc. are tightly synchronized and integrated. Just because we can observe meaningful actions from brain modules when the integration at the system level is inhibited in injured brains, does not mean that there is no integration and system property in the healthy brain. Just because two violently separated parts of an ant colony are still acting in a meaningful way, does not mean that the undivided ant colony does not act as one integrated ant colony system.

A more promising attack on the concept “individual” would have been from the level above, the social group of individuals. Science informs us that individuals are formed and influenced in zillion ways by the social environment around them, during childhood and throughout live. In fact the influence of the social context on the individual person’s formation and characteristics is so deep and wide, that there is hardly an individual character left if the social context is removed. What would be the character of a person, who had never encountered another human? His or her character would be so profoundly different, that we can not even imagine it. Thus, the activities of an individual depends so profoundly on the social environment during formation and for each and every decision taken through lifetime, that one can justifiably question if it is warranted to attribute responsibility, punishment, reward, or ownership of resources to individuals without taking into account the current and formative social context. Hence, while Harari’s conclusion that the individual may not be a solid foundation for humanism and liberal societies, his arguments are based on pathological cases and hence unnecessarily weak.

Similarly central to our notions of humanism and liberalism is the endowment of the individual with free will. How can we hold a person responsible for his or her actions, if there is no free will? The whole legal code and our political system of democracy and civil participation is based on the assumption of free will and accountability. However, Harari argues, there is really no possibility for a free will if you take science and physics seriously. If all molecules, neuron cells and chemical processes in the brain abide by the laws of physics, all actions and decisions of the brain are determined by these laws. There is no way that some obscure process could interfere, violate the natural laws, inject a free will and alter the sequence of actions. Even if the laws of physics are not deterministic as some interpretations of quantum mechanics suggest, Harari continues, free will is not possible because even a stochastic result of a physical process based on the probability distributions prescribed by quantum mechanics cannot be altered at will. Any measurable effect of a ``free will’’ would violate the laws of physics. And if it is not measurable it has no consequence.

Here Harari is on more solid ground but he fails to elaborate some subtleties that are of utmost importance for his conclusions. Even if we assume for the sake of the argument that the physical laws are purely deterministic, it does not mean there is no choice. A deterministic world where each and every action at any time is fully defined by the current state can still allow choice. To see this, consider your navigation system in your car. If you select a target address that navigator will identify several possible routes which are differentiated by the length, the estimated traveling time, the aesthetics of the views and other characteristics. If you define your objective as reaching your destination as soon as possible, the navigator will select the fastest route which may not be the shortest or the most scenic. If your objective is to minimize fuel consumption, the navigator will pick the shortest route. Thus, if we assume that the car’s engine, gears and wheels all follow strictly deterministic laws of physics, the navigator will still consider different choices and select the one that meets your objectives best. Hence, the navigator has choices to select without violating deterministic physical laws. If we include the objectives in our consideration, we see that the navigator will in fact act fully deterministic by selecting the same route for a given destination and a given objective.

The human decision process works similarly although it considers many more options and objectives. There are the objectives of survival, obtaining food, reproduction, earning money, and visiting a relative at 6pm, among others. If you for now conclude that the last one is most important, because it is 5:30pm, your decision process will consider the options you have, and you will select the one that meets best your objectives. So like the navigator you do have choices to select from and you will select the option that seems to be best for you. How do you know what is best for you? You do not have precise knowledge but you make an assessment that most of the time works pretty well. It is based on you genetic disposition and on the experience you have made earlier in your life. If you have experienced a traumatic car accident you may conclude, that driving slower is better, which may influence the selection of the route. If you have been in contact with law enforcement procedures before, because you have cut down your neighbor’s tree, you may conclude that cutting down another tree is not the best route of action for you. Thus, assigning responsibilities to individuals, reward them if they abide by rules and punish them if they don’t, shape the individual’s assessment of possible actions and thus influences the decisions taken. So it turns out that in a fully deterministic world it makes a lot of sense to formulate laws, and hand out rewards and punishments to individuals who have no free will.

Even though Harari’s premises of a deterministic world may be correct, his conclusion that the concept of free will is a worthless delusion, may not, which eventually jeopardizes all his further arguments about humanism as modern religion and the future path our societies may take. Regrettably, Harari does not diverge into these subtleties which limits the scope and depth of his reasoning, and the conclusions that he proposes to the reader come with the doubt that some additional healthy rigidity may have changed them.

But again, these are minor flaws in a barrel of gems and some shortcomings in the story line notwithstanding, this narrative about the past and possible future of humanity is enticing, thrilling and, by and large, convincing.

(AJ May 2018)