Homo Deus

Yuval Noah Harari
-min read
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A thought-provoking look at how the current trends in science and technology may progress. It traces the origins of our present-day conditioning to loosen its grip and enable us to think in far more imaginative ways about our future.

The New Human Agenda

Half of humankind is expected to be overweight by 2030.  In 2010 famine and malnutrition combined killed about 1 million people, whereas obesity killed 3 million.

‘Logic bombs’ — malicious software codes planted in peacetime and operated at a distance. It is highly likely that networks controlling vital infrastructure facilities in the USA and many other countries are already crammed with such codes.

Kurzweil and de Grey maintain that anyone possessing a healthy body and a healthy bank account in 2050 will have a serious shot at immortality by cheating death a decade at a time.

You obviously learn new things even in your forties and fifties, but life is generally divided into a learning period followed by a working period. When you live to be 150 that won’t do, especially in a world that is constantly being shaken by new technologies.

On the psychological level, happiness depends on expectations rather than objective conditions. The bad news is that as conditions improve, expectations balloon.

Part I: Homo Sapiens Conquers the World

The belief that humans have eternal souls whereas animals are just evanescent bodies is a central pillar of our legal, political and economic system.

What happens in the mind that doesn’t happen in the brain? If nothing happens in the mind except what happens in our massive network of neurons – then why do we need the mind?

Is there any algorithm in the huge realm of mathematics that contains a subjective experience? So far, we don’t know of any such algorithm.

In order to determine whether a computer has a mind, you should communicate simultaneously both with that computer and with a real person, without knowing which is which (see The Turing Test). You can ask whatever questions you want, you can play games, argue, and even flirt with them.

All large-scale human cooperation is ultimately based on our belief in imagined orders. These are sets of rules that, despite existing only in our imagination, we believe to be as real and inviolable as gravity.

Most people presume that reality is either objective or subjective, however, there is a third level of reality: the intersubjective level. Intersubjective entities depend on communication among many humans rather than on the beliefs and feelings of individual humans.

Part II: Home Sapiens Gives Meaning to the World

Religion and Science

Religion is anything that confers superhuman legitimacy on human social structures. It legitimises human norms and values by arguing that they reflect superhuman laws.

If you tell communists or liberals that they are religious, they think you accuse 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 which humans must nevertheless obey. As far as we know, all human societies believe in this.

Religion is interested above all in order. It aims to create and maintain the social structure. Science is interested above all in power. It aims to acquire the power to cure diseases, fight wars and produce food.

The Modern Covenant

The entire contract can be summarised in a single phrase: humans agree to give up meaning in exchange for power.

On the practical level, modern life consists of a constant pursuit of power within a universe devoid of meaning. Modern culture is the most powerful in history, and it is ceaselessly researching, inventing, discovering and growing. At the same time, it is plagued by more existential angst than any previous culture.

In order to ensure perpetual growth, we must somehow discover an inexhaustible store of resources. The human economy can grow because humans can discover new materials and sources of energy.

The traditional view of the world as a pie of a fixed size presupposes there are only two kinds of resources in the world: raw materials and energy. But in truth, there are three kinds of resources: raw materials, energy and knowledge. Raw materials and energy are exhaustible – the more you use, the less you have. Knowledge, in contrast, is a growing resource – the more you use, the more you have.

The Humanist Revolution

All humanist sects believe that human experience is the supreme source of authority and meaning, yet they interpret human experience in three different ways:

  • Liberal humanism, holds that each human being is a unique individual possessing a distinctive inner voice and a never-to-be-repeated string of experiences.
  • Socialist humanism takes a very different course. Socialists blame liberals for focusing our attention on our own feelings instead of on what other people experience.
  • Evolutionary humanism has a different solution to the problem of conflicting human experiences. Rooting itself in the firm ground of Darwinian evolutionary theory, it says that conflict is something to applaud rather than lament.

Not all evolutionary humanists are racists, and not every belief in humankind’s potential for further evolution necessarily calls for setting up police states and concentration camps.

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

This book began by forecasting that in the twenty-first century, humans will try to attain immortality, bliss and divinity. This forecast isn’t very original or far-sighted. It simply reflects the traditional ideals of liberal humanism. Since humanism has long sanctified the life, the emotions and the desires of human beings, it’s hardly surprising that a humanist civilisation will want to maximise human lifespans, human happiness and human power.

Part III: Homo Sapiens Loses Control

Free Will

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

The sacred word ‘freedom’ turns out to be, just like ‘soul’, an empty term that carries no discernible meaning. Free will exists only in the imaginary stories we humans have invented.

These are not just hypotheses or philosophical speculations. Today we can use brain scanners to predict people’s desires and decisions well before they are aware of them.

Neural events in the brain indicating the person’s decision begin from a few hundred milliseconds to a few seconds before the person is aware of this choice.

Two Selves

The notion that you have a single self and that you could therefore distinguish your authentic desires from alien voices is just another liberal myth, debunked by the latest scientific research.

Behavioural economists are shaking the core of the liberal world view. They are exposing the existence of at least two different selves within us: the experiencing self and the narrating self (see my notes on Thinking Fast & Slow by Daniel Khaneman)

The experiencing self is our moment-to-moment consciousness. Retrieving memories, telling stories and making big decisions are all the monopoly of a very different entity inside us: the narrating self.

Paradoxically, the more sacrifices we make for an imaginary story, the stronger the story becomes, because we desperately want to give meaning to these sacrifices and to the suffering we have caused (see Sunk Cost Fallacy).

The Great Decoupling

Humans are in danger of losing their value, because intelligence is decoupling from consciousness.

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 still find value in humans collectively, but not in unique individuals.
  3. The system will still find value in some unique individuals, but these will be a new elite of upgraded superhumans rather than the mass of the population.

Is it a coincidence that universal rights were proclaimed at the same historical juncture that universal conscription was decreed?

Some people argue that even if an algorithm could outperform doctors and pharmacists in the technical aspects of their professions, it could never replace their human touch. If your CT indicates you have cancer, would you like to receive the news from a caring and empathetic human doctor, or from a machine? Well, how about receiving the news from a caring and empathetic machine that tailors its words to your personality type? Remember that organisms are algorithms, and Watson could detect your emotional state with the same accuracy that it detects your tumours.

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 you build the calculator. Whether you build an abacus from 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?

It is crucial to realise that this entire trend is fuelled by biological insights more than by computer science. It is the life sciences that have concluded that organisms are algorithms.

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.

The Data Religion

Dataism points 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.

Capitalism did not defeat communism because capitalism was more ethical, because individual liberties are sacred or because God was angry with the heathen communists. Rather, capitalism won the Cold War because distributed data processing works better than centralised data processing, at least in periods of accelerating technological changes.

As the global data-processing system becomes all-knowing and all-powerful, so connecting to the system becomes the source of all meaning. Humans want to merge into the data flow because when you are part of the data flow you are part of something much bigger than yourself. Traditional religions told you that your every word and action was part of some great cosmic plan, and that God watched you every minute and cared about all your thoughts and feelings. Data religion now says that your every word and action is part of the great data flow, that the algorithms are constantly watching you and that they care about everything you do and feel. Most people like this very much.

For true-believers, to be disconnected from the data flow risks losing the very meaning of life. What’s the point of doing or experiencing anything if nobody knows about it, and if it doesn’t contribute something to the global exchange of information?

The new motto says: ‘If you experience something – record it. If you record something – upload it. If you upload something – share it.’

Whereas humanism commanded: ‘Listen to your feelings!’ Dataism now commands: ‘Listen to the algorithms! They know how you feel.’


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?

Miscellaneous Quotes

How do you know if an entity is real? Very simple – just ask yourself, ‘Can it suffer?’

War exposes the truth about life, and awakens the will for power, for glory and for conquest.

Already today ‘enhanced’ dairy cows have such heavy udders that they can barely walk, while ‘upgraded’ chickens cannot even stand up. If customers ask us only for the cheapest meat possible – that’s what the customers will get. Customers need to decide what is most important to them – price, or something else.’

Wilhelm von Humboldt – one of the chief architects of the modern education system – said that the aim of existence is ‘a distillation of the widest possible experience of life into wisdom’. He also wrote that ‘there is only one summit in life – to have taken the measure in feeling of everything human’.

Most scientific research about the human mind and the human experience has been conducted on people from Western, educated, industrialised, rich and democratic (WEIRD) societies, who do not constitute a representative sample of humanity.