Homo Deus: A Brief History of Tomorrow

by Yuval Noah Harari

Throughout history most humans took war for granted, whereas peace was a temporary and precarious state. International relations were governed by the Law of the Jungle, according to which even if two polities lived in peace, war always remained an option.

terrorism is a strategy of weakness adopted by those who lack access to real power. At least in the past, terrorism worked by spreading fear rather than by causing significant material damage. Terrorists usually don’t have the strength to defeat an army, occupy a country or destroy entire cities.

In essence, terrorism is a show. Terrorists stage a terrifying spectacle of violence that captures our imagination and makes us feel as if we are sliding back into medieval chaos. Consequently states often feel obliged to react to the theatre of terrorism with a show of security, orchestrating immense displays of force, such as the persecution of entire populations or the invasion of foreign countries. In most cases, this overreaction to terrorism poses a far greater threat to our security than the terrorists themselves.

This is the paradox of historical knowledge. Knowledge that does not change behaviour is useless. But knowledge that changes behaviour quickly loses its relevance. The more data we have and the better we understand history, the faster history alters its course, and the faster our knowledge becomes outdated.

Each and every one of us has been born into a given historical reality, ruled by particular norms and values, and managed by a unique economic and political system. We take this reality for granted, thinking it is natural, inevitable and immutable. We forget that our world was created by an accidental chain of events, and that history shaped not only our technology, politics and society, but also our thoughts, fears and dreams. The cold hand of the past emerges from the grave of our ancestors, grips us by the neck and directs our gaze towards a single future. We have felt that grip from the moment we were born, so we assume that it is a natural and inescapable part of who we are. Therefore we seldom try to shake ourselves free, and envision alternative futures.

Humans thereby came to identify lawns with political power, social status and economic wealth.

Having read this short history of the lawn, when you now come to plan your dream house you might think twice about having a lawn in the front yard. You are of course still free to do it. But you are also free to shake off the cultural cargo bequeathed to you by European dukes, capitalist moguls and the Simpsons – and imagine for yourself a Japanese rock garden, or some altogether new creation. This is the best reason to learn history: not in order to predict the future, but to free yourself of the past and imagine alternative destinies. Of course this is not total freedom – we cannot avoid being shaped by the past. But some freedom is better than none.

Scientists divide the history of our planet into epochs such as the Pleistocene, the Pliocene and the Miocene. Officially, we live in the Holocene epoch. Yet it may be better to call the last 70,000 years the Anthropocene epoch: the epoch of humanity. For during these millennia Homo sapiens became the single most important agent of change in the global ecology.

An algorithm is a methodical set of steps that can be used to make calculations, resolve problems and reach decisions. An algorithm isn’t a particular calculation, but the method followed when making the calculation.

The Agricultural Revolution was thus both an economic and a religious revolution. New kinds of economic relations emerged together with new kinds of religious beliefs that justified the brutal exploitation of animals.

in fact modernity is a surprisingly simple deal. The entire contract can be summarised in a single phrase: humans agree to give up meaning in exchange for power.

Modern culture rejects this belief in a great cosmic plan. We are not actors in any larger-than-life drama. Life has no script, no playwright, no director, no producer – and no meaning. To the best of our scientific understanding, the universe is a blind and purposeless process, full of sound and fury but signifying nothing. During our infinitesimally brief stay on our tiny speck of a planet, we fret and strut this way and that, and then are heard of no more. Since there is no script, and since humans fulfil no role in any great drama, terrible things might befall us and no power will come to save us or give meaning to our suffering. There won’t be a happy ending, or a bad ending, or any ending at all. Things just happen, one after the other. The modern world does not believe in purpose, only in cause. If modernity has a motto, it is ‘shit happens’.

On the other hand, if shit just happens, without any binding script or purpose, then humans too are not confined to any predetermined role. We can do anything we want – provided we can find a way. We are constrained by nothing except our own ignorance. Plagues and droughts have no cosmic meaning – but we can eradicate them. Wars are not a necessary evil on the way to a better future – but we can make peace. No paradise awaits us after death – but we can create paradise here on earth and live in it for ever, if we just manage to overcome some technical difficulties.

Modernity, in contrast, is based on the firm belief that economic growth is not only possible, but absolutely essential. Prayers, good deeds and meditation might be comforting and inspiring, but problems such as famine, plague and war can only be solved through growth. This fundamental dogma can be summarised in one simple idea: ‘If you have a problem, you probably need more stuff, and in order to have more stuff, you must produce more of it.’

Modernity turned the world upside down. It convinced human collectives that equilibrium is far more frightening than chaos, and because avarice fuels growth, it is a force for good. Modernity accordingly inspired people to want more, and dismantled the age-old disciplines that curbed greed.

Capitalists are, again, quick to give all the credit to the invisible hand of the market. Yet the market’s hand is not only invisible, it is also blind, and by itself could never have saved human society. Indeed, not even a country fair can maintain itself without the helping hand of some god, king or church. If everything is for sale, including the courts and the police, trust evaporates, credit vanishes and business withers.6 What, then, rescued modern society from collapse? Humankind was salvaged not by the law of supply and demand, but rather by the rise of a revolutionary new religion – humanism.

Humanism thus sees life as a gradual process of inner change, leading from ignorance to enlightenment by means of experiences.

the orthodox branch of humanism is known as ‘liberal humanism’ or simply as ‘liberalism’.* It is liberal politics that believes the voter knows best. Liberal art holds that beauty is in the eye of the beholder. Liberal economics maintains that the customer is always right. Liberal ethics advises us that if it feels good, we should go ahead and do it. Liberal education teaches us to think for ourselves, because we will find all the answers within.

During the nineteenth and twentieth centuries, as humanism gained increasing social credibility and political power, it sprouted two very different offshoots: socialist humanism, which encompassed a plethora of socialist and communist movements, and evolutionary humanism, whose most famous advocates were the Nazis. Both offshoots agreed with liberalism that human experience is the ultimate source of meaning and authority.

However, both socialists and evolutionary humanists pointed out that the liberal understanding of the human experience is flawed. Liberals think the human experience is an individual phenomenon. But there are many individuals in the world, and they often feel different things and have contradictory desires.

socialists discourage self-exploration and advocate the establishment of strong collective institutions – such as socialist parties and trade unions – that aim to decipher the world for us. Whereas in liberal politics the voter knows best, and in liberal economics the customer is always right, in socialist politics the party knows best, and in socialist economics the trade union is always right. Authority and meaning still come from human experience – both the party and the trade union are composed of people and work to alleviate human misery – yet individuals must listen to the party and the trade union rather than to their personal feelings.

Evolutionary humanism has a different solution to the problem of conflicting human experiences. Rooting itself in the firm ground of Darwinian evolutionary theory, it insists that conflict is something to applaud rather than lament. Conflict is the raw material of natural selection, which pushes evolution forward. Some humans are simply superior to others, and when human experiences collide, the fittest humans should steamroll everyone else.

Nazism was born from the pairing of evolutionary humanism with particular racial theories and ultra-nationalist emotions.

Evolutionary humanism played an important part in the shaping of modern culture, and is likely to play an even greater role in the shaping of the twenty-first century.

Whereas liberals tiptoe around the minefield of cultural comparisons, fearful of committing some politically incorrect faux pas, and whereas socialists leave it to the party to find the correct path through this minefield, evolutionary humanists gleefully jump right in, setting off all the mines and relishing the mayhem. They may start by pointing out that both liberals and socialists draw the line at other animals, and have no trouble admitting that humans are superior to wolves, and that consequently human music is far more valuable than wolf howls. Yet humankind itself is not exempt from the forces of evolution. Just as humans are superior to wolves, so some human cultures are more advanced than others.

Lenin was once asked to define communism in a single sentence. ‘Communism is power to worker councils,’ he said, ‘plus electrification of the whole country.’ There can be no communism without electricity, without railroads, without radio. You couldn’t have established a communist regime in sixteenth-century Russia, because communism necessitates the concentration of information and resources in one hub. ‘From each according to his ability, to each according to his needs’ only works when produce can easily be collected and distributed across vast distances, and when activities can be monitored and coordinated over entire countries.

Marx and his followers understood the new technological realities and the new human experiences, so they had relevant answers to the new problems of industrial society, as well as original ideas about how to benefit from the unprecedented opportunities. The socialists created a brave new religion for a brave new world. They promised salvation through technology and economics, thus establishing the first techno-religion in history, and changing the foundations of ideological discourse.

The electrochemical brain processes that result in murder are either deterministic or random or a combination of both – but they are never free.

To the best of our scientific understanding, determinism and randomness have divided the entire cake between them, leaving not even a crumb for ‘freedom’. The sacred word ‘freedom’ turns out to be, just like ‘soul’, a hollow term empty of any discernible meaning. Free will exists only in the imaginary stories we humans have invented.

The last nail in freedom’s coffin is provided by the theory of evolution. Just as evolution cannot be squared with eternal souls, neither can it swallow the idea of free will. For if humans are free, how could natural selection have shaped them? According to the theory of evolution, all the choices animals make – whether of habitat, food or mates – reflect their genetic code.

When confronted with such scientific explanations people often brush them aside, pointing out that they feel free and that they act according to their own wishes and decisions. This is true. Humans act according to their desires. If by ‘free will’ we mean the ability to act according to our desires – then yes, humans have free will, and so do chimpanzees, dogs and parrots. When Polly wants a cracker, Polly eats a cracker. But the million-dollar question is not whether parrots and humans can act upon their inner desires – the question is whether they can choose their desires in the first place.

I don’t choose my desires. I only feel them, and act accordingly.

A robo-rat is a run-of-the-mill rat with a twist: scientists have implanted electrodes into the sensory and reward areas in the rat’s brain. This enables the scientists to manoeuvre the rat by remote control. After short training sessions, researchers have managed not only to make the rats turn left or right, but also to climb ladders, sniff around garbage piles, and do things that rats normally dislike, such as jumping from extreme heights. Armies and corporations are showing keen interest in the robo-rats, hoping they will prove useful in many tasks and situations. For example, robo-rats might help detect survivors trapped under collapsed buildings, locate bombs and booby traps, and map underground tunnels and caves. Animal-welfare activists have voiced concern about the suffering such experiments inflict on the rats. Professor Sanjiv Talwar of the State University of New York, one of the leading robo-rat researchers, has dismissed these concerns, arguing that the rats actually enjoy the experiments. After all, explains Talwar, the rats ‘work for pleasure’ and when the electrodes stimulate the reward centres in their brains, ‘the rat feels Nirvana’.3 To the best of our understanding, the rat doesn’t feel that somebody else controls her, and she doesn’t feel that she is being coerced to do anything against her will. When Professor Talwar presses the remote control, the rat wants to move to the left, which is why she moves to the left. When the professor presses another sw...

for the first time in my life, everything in my head finally shut up . . . My brain without self-doubt was a revelation. There was suddenly this incredible silence in my head . . . I hope you can sympathise with me when I tell you that the thing I wanted most acutely for the weeks following my experience was to go back and strap on those electrodes. I also started to have a lot of questions. Who was I apart from the angry bitter gnomes that populate my mind and drive me to failure because I’m too scared to try? And where did those voices come from?’7 Some of those voices repeat society’s prejudices, some echo our personal history, and some articulate our genetic legacy. All of them together, says Sally, create an invisible story that shapes our conscious decisions in ways we seldom grasp. What would happen if we could rewrite our inner monologues, or even silence them completely on occasion?

Gazzaniga concluded that the left hemisphere of the brain is the seat not only of our verbal abilities, but also of an internal interpreter that constantly tries to make sense of our life, using partial clues in order to concoct plausible stories.

Most of our critical life choices – of partners, careers, residences and holidays – are taken by our narrating self.

Truth be told, the experiencing self and the narrating self are not completely separate entities but are closely intertwined. The narrating self uses our experiences as important (but not exclusive) raw materials for its stories. These stories, in turn, shape what the experiencing self actually feels.

Furthermore, the experiencing self is often strong enough to sabotage the best-laid plans of the narrating self. I might, for instance, make a New Year’s resolution to start a diet and go to the gym every day. Such grand decisions are the monopoly of the narrating self. But the following week when it’s gym time, the experiencing self takes over. I don’t feel like going to the gym, and instead I order pizza, sit on the sofa and turn on the TV. Nevertheless, most of us identify with our narrating self. When we say ‘I’, we mean the story in our head, not the onrushing stream of experiences we undergo. We identify with the inner system that takes the crazy chaos of life and spins out of it seemingly logical and consistent yarns. It doesn’t matter that the plot is full of lies and lacunas, and is rewritten again and again, so that today’s story flatly contradicts yesterday’s. The important thing is that we always retain the feeling that we have a single unchanging identity from birth to death (and perhaps even beyond). This gives rise to the questionable liberal belief that I am an individual, and that I possess a clear and consistent inner voice that provides meaning to the entire universe.

which of the two is really important, intelligence or consciousness? As long as they went hand in hand, debating their relative value was just an amusing pastime for philosophers. But in the twenty-first century this is becoming an urgent political and economic issue. And it is sobering to realise that, at least for armies and corporations, the answer is straightforward: intelligence is mandatory but consciousness is optional. Armies and corporations cannot function without intelligent agents, but they don’t need consciousness and subjective experiences.

The idea that humans will always have a unique ability beyond the reach of non-conscious algorithms is just wishful thinking. The current scientific answer to this pipe dream can be summarised in three simple principles: 1. Organisms are algorithms. Every animal – including Homo sapiens – is an assemblage of organic algorithms shaped by natural selection over millions of years of evolution. 2. Algorithmic calculations are not affected by the materials from which the calculator is built. Whether an abacus is made of wood, iron or plastic, two beads plus two beads equals four beads. 3. Hence there is no reason to think that organic algorithms can do things that non-organic algorithms will never be able to replicate or surpass. As long as the calculations remain valid, what does it matter whether the algorithms are manifested in carbon or silicon?

The new technologies of the twenty-first century may thus reverse the humanist revolution, stripping humans of their authority, and empowering non-human algorithms instead.

In the twenty-first century the individual is more likely to disintegrate gently from within than to be brutally crushed from without. Today most corporations and governments pay homage to my individuality, and promise to provide medicine, education and entertainment customised to my unique needs and wishes. But in order to do so, corporations and governments first need to deconstruct me into biochemical subsystems, monitor these subsystems with ubiquitous sensors and decipher their working with powerful algorithms. In the process, the individual will transpire to be nothing but a religious fantasy. Reality will be a mesh of biochemical and electronic algorithms, without clear borders, and without individual hubs.

If scientific discoveries and technological developments split humankind into a mass of useless humans and a small elite of upgraded superhumans, or if authority shifts altogether away from human beings into the hands of highly intelligent algorithms, then liberalism will collapse.

Techno-humanism agrees that Homo sapiens as we know it has run its historical course and will no longer be relevant in the future, but concludes that we should therefore use technology in order to create Homo deus – a much superior human model.

Modern humanity is sick with FOMO – Fear Of Missing Out – and though we have more choice than ever before, we have lost the ability to really pay attention to whatever we choose.

the US army’s ‘attention helmet’ is meant to help people focus on well-defined tasks and speed up their decision-making process. It may, however, reduce their ability to show empathy and tolerate doubts and inner conflicts.

a life of resolute decisions and quick fixes may be poorer and shallower than one of doubts and contradictions.

Techno-humanism faces an impossible dilemma here. It considers the human will to be the most important thing in the universe, hence it pushes humankind to develop technologies that can control and redesign the will. After all, it’s tempting to gain control over the most important thing in the world. Yet should we ever achieve such control, techno-humanism would not know what to do with it, because the sacred human would then become just another designer product. We can never deal with such technologies as long as we believe that the human will and the human experience are the supreme source of authority and meaning.

Political scientists also increasingly interpret human political structures as data-processing systems. Like capitalism and communism, so democracies and dictatorships are in essence competing mechanisms for gathering and analysing information. Dictatorships use centralised processing methods, whereas democracies prefer distributed processing.

Over the past decades democracy gained the upper hand because under the unique conditions of the late twentieth century, distributed processing worked better. Under alternative conditions – those prevailing in the ancient Roman Empire, for instance – centralised processing had an edge, which is why the Roman Republic fell and power shifted from the Senate and popular assemblies into the hands of a single autocratic emperor. This implies that as data-processing conditions change again in the twenty-first century, democracy might decline and even disappear.