Homo Deus - by Yuval Noah Harari

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 next 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.

Studying history aims to loosen the grip of the past. It enables us to turn our head this way and that, and begin to notice possibilities that our ancestors could not imagine, or didn’t want us to imagine. By observing the accidental chain of events that led us here, we realise how our very thoughts and dreams took shape—and we can begin to think and dream differently. Studying history will not tell us what to choose, but at least it gives us more options.

On religion

Most of the misunderstandings regarding science and religion result from faulty definitions of religion. All too often people confuse religion with superstition, spirituality, belief in supernatural powers or belief in gods. Religion is none of these things. Religion cannot be equated with superstition, because most people are unlikely to call their most cherished beliefs ‘superstitions’. We always believe in ‘the truth’; only other people believe in superstitions.

Similarly, few people put their faith in supernatural powers. For those who believe in demons, spirits and fairies, these beings are not supernatural. They are an integral part of nature, just like porcupines, scorpions and germs. Modern physicians blame disease on invisible germs, and voodoo priests blame disease on invisible spirits. There’s nothing supernatural about it: if you make some spirit angry, the spirit enters your body and causes you pain. What could be more natural than that? Only those who don’t believe in spirits think of them as standing apart from the natural order of things.

Equating religion with faith in supernatural powers implies that you can understand all known natural phenomena without religion, which is just an optional supplement. Having understood perfectly well the whole of nature, you can now choose whether or not to add some ‘super-natural’ religious dogma. Most religions, however, argue that you simply cannot understand the world without them. You will never comprehend the true reason for disease, drought or earthquakes if you do not take their dogma into account.

Defining religion as ‘belief in gods’ is also problematic. We tend to say that a devout Christian is religious because she believes in God, whereas a fervent communist isn’t religious because communism has no gods. However, religion is created by humans rather than by gods, and it is defined by its social function rather than by the existence of deities. Religion is any all-encompassing story that confers superhuman legitimacy on human laws, norms and values. It legitimises social structures by arguing that they reflect superhuman laws.

Liberals, communists and followers of other modern creeds dislike describing their own system as a ‘religion’, because they identify religion with superstitions and supernatural powers. If you tell communists or liberals that they are religious, they think you are accusing them of blindly believing in groundless pipe dreams. In fact, it means only that they believe in some system of moral laws that wasn’t invented by humans, but that humans must nevertheless obey. As far as we know, all human societies believe in this. Every society tells its members that they must obey some superhuman moral law, and that breaking this law will result in catastrophe.

Science and religion as bedfellows

It is customary to portray the history of modernity and a struggle between science and religion. In theory, both science and religion are interested above all in the truth, and because each upholds a different truth, they are doomed to clash. In fact, neither science nor religion cares that much about the truth, hence they can easily compromise, coexist and even cooperate.

Religion is interested above all in order. It aims to create and maintain the social structure. Science is interested above all in power. Through research it aims to acquire the power to cure diseases, fight wars and produce food. As individuals, scientists and priests may give immense importance to the truth; but as collective institutions, science and religion prefer order and power over truth. They therefore make good bedfellows. The uncompromising quest for truth is a spiritual journey, which can seldom remain within the confines of either religious or scientific establishments.

It would accordingly be far more accurate to view modern history as the process of formulating a deal between science and one particular religion—namely, humanism. Modern society believes in humanist dogmas, and uses science not in order to question these dogmas, but rather in order to implement them. In the twenty-first century the humanist dogmas are unlikely to be replaced by pure scientific theories. However, the covenant linking science and humanism may well crumble and give way to a very different kind of deal, between science and some new post-humanist religion.

The Humanist Revolution

The modern deal offers us power, on condition that we renounce our belief in a great cosmic plan that gives meaning to life. Yet when you examine the deal closely, you find a cunning escape clause. If humans somehow manage to find meaning without predicating it upon some great cosmic plan, this is not considered a breach of contract.

This escape clause has been the salvation of modern society, for it is impossible to sustain order without meaning. The great political, artistic and religious project of modernity has been to find a meaning to life that is not rooted in some great cosmic plan. We are not actors in a divine drama, and nobody cares about us and our deeds, so nobody sets limits to our power—but we are still convinces our lives have meaning.

As of 2016, humankind has indeed managed to have it both ways. Not only do we possess far more power than ever before, but, against all expectations, God’s death did not lead to social collapse. Throughout history prophets and philosophers have argued that if humans stopped believing in a great cosmic plan, all law and order would vanish. Yet today, those who pose the greatest threat to global law and order are precisely those people who continue to believe in God and his all-encompassing plans. God-fearing Syria is a far more violent place than the secular Netherlands.

If there is no cosmic plan, and we are not committed to any divine or natural laws, what prevents social collapse? The antidote to a meaningless and lawless existence was provided by humanism, a revolutionary new creed that conquered the world during the last few centuries. The humanist religion worships humanity, and expects humanity to play the part that God played in Christianity and Islam, and that the laws of nature played in Buddhism and Daoism. Whereas traditionally the great cosmic plan gave meaning to the life of humans, humanism reverses the roles and expects the experiences of humans to give meaning to the cosmos. According to humanism, humans must draw from within their inner experiences not only the meaning of their own lives, but also the meaning of the entire universe. This is the primary commandment humanism has given us: create meaning for a meaningless world. Accordingly, the central religious revolution of modernity was not losing faith in God; rather it was gaining faith in humanity.

For centuries humanism has been convincing us that we are the ultimate source of meaning, and that our free will is therefore the highest authority of all. Instead of waiting for some external entity to tell us what’s what, we can rely on our own feelings and desires. From infancy we are bombarded with a barrage of humanist slogans counselling us: ‘Listen to yourself, be true to yourself, trust yourself, follow your heart, do what feels good.’

The Great Decoupling

Liberals uphold free markets and democratic elections because they believe that every human is a uniquely valuable individual, whose free choices are the ultimate source of authority. In the twenty-first century three practical developments might make this belief obsolete:

  1. Humans will lose their economic and military usefulness, hence the economic and political system will stop attaching much value to them.
  2. The system will continue to find value in humans collectively, but not in unique individuals.
  3. The system will still find value in some unique individuals, but these will constitute a new elite of upgraded superhumans rather than the mass of the population.

The Useless Class

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?

True, at present there are numerous things that organic algorithms do better than non-organic ones, and experts have repeatedly declared that something will ‘for ever’ remain beyond the reach of non-organic algorithms. But it turns out that ‘for ever’ often means no more than a decade or two.


The new religions are unlikely to emerge from the aves of Afghanistan or from the madrasas of the Middle East. Rather, they will emerge from research laboratories. Just as socialism took over the world by promising salvation through steam and electricity, so in the coming decades new techno-religions may conquer the world by promising salvation through algorithms and genes.

These new techno-religions can be divided into two main types: techno-humanism and data religion. Data religion argues that humans have completed their cosmic task and should now pass the torch on to entirely new kinds of entities. 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. Homo deus will retain some essential human features, but will also enjoy upgraded physical and mental abilities that will enable it to hold its own even against the most sophisticated non-conscious algorithms. Since intelligence is decoupling from consciousness, and since non-conscious intelligence is developing at breakneck speed, humans must actively upgrade their minds if they want to stay in the game.

Seventy thousand years ago the Cognitive Revolution transformed the Sapiens mind, thereby turning an insignificant African ape into the ruler of the world. The improved Sapiens minds suddenly had access to the vast intersubjective realm, which enabled them to create gods and corporations, to build cities and empires, to invent writing and money, and eventually to split the atom and reach the moon. As far as we know, this earth-shattering revolution resulted from a few small changes in the Sapiens DNA and a slight rewiring of the Sapiens brain. If so, says techno-humanism, maybe a few additional changes to our genome and another rewiring of our brain will suffice to launch a second cognitive revolution. The mental renovations of the first Cognitive Revolution gave Homo sapiens access to the intersubjective realm and turned them into the rulers of the planet; a second cognitive revolution might give Homo deus access to unimaginable new realms and make them lords of the galaxy.

This idea is an updated variant on the old dreams of evolutionary humanism, which already a century ago called for the creation of superhumans. However, whereas Hitler and his ilk planned to create superhumans by means of selective breeding and ethnic cleansing, twenty-first century techno-humanism hopes to reach that goal far more peacefully, with the help of genetic engineering, nanotechnology and brain-computer interfaces.

The Data Religion

Dataism declares that the universe consists of data flows, and the value of any phenomenon or entity is determined by its contribution to data processing. This may strike you as some eccentric fringe notion, but in fact it has already conquered most of the scientific establishment. Dataism was born from the explosive confluence of two scientific tidal waves. In the 150 years since Charles Darwin published On the Origin of Species, the life sciences have come to see organisms as biochemical algorithms. Simultaneously, in the eight decades since Alan Turing formulated the idea of a Turing Machine, computer scientists have learned to engineer increasingly sophisticated electronic algorithms. Dataism puts the two together, pointing out that exactly the same mathematical laws apply to both biochemical and electronic algorithms. Dataism thereby collapses the barrier between animals and machines, and expects electronic algorithms to eventually decipher and outperform biochemical algorithms.

For politicians, businesspeople and ordinary consumers, Dataism offers groundbreaking technologies and immense new powers. For scholars and intellectuals it also promises to provide the scientific holy grail that has eluded us for centuries: a single overarching theory that unifies all the scientific disciplines from musicology through economics to biology. According to Dataism, Beethoven’s Fifth Symphony, a stock-exchange bubble and the flu virus are just three patterns of data flow that can be analysed using the same basic concepts and tools. This idea is extremely attractive. It gives all scientists a common language, builds bridges over academic rifts and easily exports insights across disciplinary borders. Musicologists, economists and cell biologists can finally understand each other.

In the process Dataism inverts the traditional pyramid of learning. Hitherto, data was seen as only the first step in a long chain of intellectual activity. Humans were supposed to distil data into information, information into knowledge, and knowledge into wisdom. However, Dataists believe that humans can no longer cope with the immense flow of data, hence they announced distil data into information, let alone into knowledge or wisdom. The work of processing data should therefore be entrusted to electronic algorithms, whose capacity far exceeds that of the human brain. In practice, this means that Dataists are sceptical about human knowledge and wisdom, and prefer to put their trust in Big Data and computer algorithms.

Dataism is most firmly entrenched in its two mother disciplines: computer science and biology. Of the two biology is the more important. Not only individual organisms are seen today as data-processing systems, but also entire societies such as beehives, bacteria colonies, forests and human cities. Economists increasingly interpret the economy too as a data-processing system. Experts see the economy as a mechanism for gathering data about desires and abilities, and turning this data into decisions.

According to this view, free-market capitalism and state-controlled communism aren’t competing ideologies, ethical creeds or political institutions. They are, in essence, competing data-processing systems. Capitalism uses distributed processing, whereas communism relies on centralised processing. Capitalism processes data by directly connecting all producers and consumers to one another and allowing them to exchange information freely and make decisions independently. According to this view the stock exchange is the fastest and most efficient data-processing system humankind has so far created.

Like capitalism, Dataism too began as a neutral scientific theory, but is now mutating into a religion that claims to determine right and wrong. The supreme value of this new religion is ‘information flow’. If life is the movement of information, and if we think that life is good, it follows that we should deepen and broaden the flow of information in the universe. According to Dataism, human experiences are not sacred and Homo sapiens isn’t the apex of creation or a precursor of some future Homo deus. Humans are merely tools for creating the Internet-of-All-Things, which may eventually spread out from planet Earth to pervade the whole galaxy and even the whole universe. This cosmic data-processing system would be like God. It will be everywhere and will control everything, and humans are destined to merge into it.

If we think in terms of months, we had probably better focus on immediate problems such as the turmoil in the Middle East, the refugee crisis in Europe and the slowing of the Chinese economy. If we think in terms of decades, then global warming, growing inequality and the disruption of the job market loom large. Yet if we take the really grand view of life, all other problems and developments are overshadowed by three interlinked processes:

  1. Science is converging on an all-encompassing dogma, which says that organisms are algorithms and life is data processing.
  2. Intelligence is decoupling from consciousness.
  3. Non-conscious but highly intelligent algorithms may soon know us better than we know ourselves.

These three processes raise three key questions, which I hope will stick in your mind long after you have finished this book:

  1. Are organisms really just algorithms, and is life really just data processing?
  2. What’s more valuable — intelligence or consciousness?
  3. What will happen to society, politics and daily life when non-conscious but highly intelligent algorithms know us better than we know ourselves?