Homo Deus: A Brief History of Tomorrow

by Yuval Noah Harari

If you distort reality too much, it will weaken you, and you will not be able to compete against more clear-sighted rivals. On the other hand, you cannot organise masses of people effectively without relying on some fictional myths. So if you stick to unalloyed reality, without mixing any fiction with it, few people will follow you.

in many countries around the world, including the USA and the UK, witnesses in courts put their hand on a bible when swearing to tell the truth, the whole truth, and nothing but the truth. It’s ironic that they swear to tell the truth on a book brimming with so many fictions, myths and errors.

God helps those who help themselves. This is a roundabout way of saying that God doesn’t exist, but if our belief in Him inspires us to do something ourselves – it helps. Antibiotics, unlike God, help even those who don’t help themselves. They cure infections whether you believe in them or not.

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.

A Jewish boy comes to his father and asks, ‘Dad, why shouldn’t we eat pork?’ The father thoughtfully strokes his long curly beard and answers, ‘Well, Yankele, that’s how the world works. You are still young and you don’t yet understand, but if we eat pork, God will punish us and we will come to a bad end. It isn’t my idea. It’s not even the rabbi’s idea. If the rabbi had created the world, maybe he would have created a world in which pork was perfectly kosher. But the rabbi didn’t create the world – God did. And God said, I don’t know why, that we shouldn’t eat pork. So we shouldn’t. Capeesh?’ In 1943 a German boy comes to his father, a senior SS officer, and asks, ‘Dad, why are we killing the Jews?’ The father, putting on his shiny leather boots, explains, ‘Well, Fritz, that’s how the world works. You are still young and don’t yet understand, but if we allow the Jews to live they will cause the degeneration and extinction of humankind. It’s not my idea. It’s not even the Führer’s idea. If Hitler had created the world, maybe he would have created a world in which the laws of natural selection did not apply, and Jews and Aryans could all live together in perfect harmony. But Hitler didn’t create the world. He just managed to decipher the laws of nature and then instructed us how to live in line with them. If we disobey these laws, we will come to a bad end. Ist das klar?!’ In 2016 a British boy comes to his father, a liberal MP, and asks, ‘Dad, why should we care about the ...

Religion gives a complete description of the world, and offers us a well-defined contract with predetermined goals. ‘God exists. He told us to behave in certain ways. If you obey God, you’ll be admitted to heaven. If you disobey Him, you’ll burn in hell.’ The very clarity of this deal allows society to define common norms and values that regulate human behaviour. Spiritual journeys are nothing like that. They usually take people in mysterious ways towards unknown destinations. The quest usually begins with some big question, such as who am I? What is the meaning of life? What is good? Whereas most people just accept the ready-made answers provided by the powers that be, spiritual seekers are not so easily satisfied. They are determined to follow the big question wherever it leads, and not just to places they know well or wish to visit. Thus for most people, academic studies are a deal rather than a spiritual journey, because they take us to a predetermined goal approved by our elders, governments and banks.

According to dualism, the good god created pure and everlasting souls that lived in a blissful world of spirit. However, the evil god – sometimes named Satan – created another world, made of matter. Satan didn’t know how to make his creation endure, hence in the world of matter everything rots and disintegrates. In order to breathe life into his defective creation, Satan tempted souls from the pure world of spirit, and confined them inside material bodies. That’s what a human is – a good spiritual soul trapped inside an evil material body. Since the soul’s prison – the body – decays and eventually dies, Satan ceaselessly tempts the soul with bodily delights, and above all with food, sex and power. When the body disintegrates and the soul has the opportunity to escape back to the spiritual world, its craving for bodily pleasures lures it back inside some new material body. The soul thus transmigrates from body to body, wasting its days in pursuit of food, sex and power.

In Zen Buddhism it is said that ‘If you meet the Buddha on the road, kill him.’ Which means that if while walking on the spiritual path you encounter the rigid ideas and fixed laws of institutionalised Buddhism, you must free yourself from them too.

As for the idea that the ancient Jews carefully preserved the biblical text without adding or subtracting anything, scientists point out that biblical Judaism was not a scripture-based religion at all. Rather, it was a typical Iron Age cult, similar to many of its Middle Eastern neighbours. It had no synagogues, yeshivas, rabbis – or even a bible. Instead, it had elaborate temple rituals, most of which involved sacrificing animals to a jealous sky god so that he would bless his people with seasonal rains and military victories. Its religious elite consisted of priestly families, who owed everything to birth and nothing to intellectual prowess. The mostly illiterate priests were busy with the temple ceremonies and had little time for writing or studying any scriptures. During the Second Temple period a rival religious elite gradually formed. Due partly to Persian and Greek influences, Jewish scholars who wrote and interpreted texts gained increasing prominence. These scholars eventually came to be known as rabbis, and the texts they compiled were christened ‘the Bible’. Rabbinical authority rested on individual intellectual abilities rather than on birth. The clash between this new literate elite and the old priestly families was inevitable. Fortunately for the rabbis, the Romans torched Jerusalem and its temple in AD 70 while suppressing the Great Jewish Revolt. With the temple in ruins, the priestly families lost their religious authority, their economic power base and th...

Consequently, although science has much more to contribute to ethical debates than we commonly think, there is a line it cannot cross, at least not yet. Without the guiding hand of some religion, it is impossible to maintain large-scale social orders. Even universities and laboratories need religious backing. Religion provides the ethical justification for scientific research, and in exchange gets to influence the scientific agenda and the uses of scientific discoveries. Hence you cannot understand the history of science without taking religious beliefs into account. Scientists seldom dwell on this fact, but the Scientific Revolution itself began in one of the most dogmatic, intolerant and religious societies in history.

If you had travelled to Cairo or Istanbul around 1600, you would find there a multicultural and tolerant metropolis, where Sunnis, Shiites, Orthodox Christians, Catholics, Armenians, Copts, Jews and even the occasional Hindu lived side by side in relative harmony. Though they had their share of disagreements and riots, and though the Ottoman Empire routinely discriminated against people on religious grounds, it was a liberal paradise compared with Europe. If you had then sailed on to contemporary Paris or London, you would have found cities awash with religious extremism, in which only those belonging to the dominant sect could live. In London they killed Catholics, in Paris they killed Protestants, the Jews had long been driven out, and nobody in his right mind would dream of letting any Muslims in. And yet, the Scientific Revolution began in London and Paris rather than in Cairo and Istanbul.

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.

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.

Yet 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. Until modern times most cultures believed that humans played a part in some great cosmic plan. The plan was devised by the omnipotent gods or by the eternal laws of nature, and human-kind could not change it. The cosmic plan gave meaning to human life, but also restricted human power.

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.

The modern pursuit of power is fuelled by the alliance between scientific progress and economic growth. For most of history science progressed at a snail’s pace, while the economy was in deep freeze.

Suppose you live in a medieval town that suffers from annual outbreaks of dysentery. You resolve to find a cure. You need funding to set up a workshop, buy medicinal herbs and exotic chemicals, pay assistants and travel to consult with famous doctors. You also need money to feed yourself and your family while you are busy with your research. But you don’t have much money. You can approach the local miller, baker and blacksmith and ask them to meet all your needs for a few years, promising that when you finally discover the cure and become wealthy, you will pay your debts. Unfortunately, the miller, baker and blacksmith are unlikely to consent. They need to feed their families today, and they have no faith in miracle medicines. They weren’t born yesterday, and in all their years they have never heard of anyone finding a new medicine for some dreaded disease. If you want provisions – you have to pay cash. But how can you get the money when you haven’t discovered the medicine yet, and all your time is taken up with research? Reluctantly, you go back to tilling your field, dysentery keeps tormenting the townsfolk, nobody tries to develop new remedies, and not a single gold coin changes hands. That’s how the economy languished, and science stood still.

The traditional view of the world as a pie of a fixed size presupposes that 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. Indeed, when you increase your stock of knowledge, it can give you more raw materials and energy as well. If I invest $100 million searching for oil in Alaska and I find it, then I now have more oil, but my grandchildren will have less of it. In contrast, if I invest $100 million researching solar energy, and I find a new and more efficient way of harnessing it, then both I and my grandchildren will have more energy.

For thousands of years the scientific road to growth was blocked because people believed that holy scriptures and ancient traditions already contained all the important knowledge the world had to offer.

The greatest scientific discovery was the discovery of ignorance. Once humans realised how little they knew about the world, they suddenly had a very good reason to seek new knowledge, which opened up the scientific road to progress.

People who believe in the hi-tech Ark should not be put in charge of the global ecology, for the same reason that people who believe in a heavenly afterlife should not be given nuclear weapons.

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.

You cannot experience something if you don’t have the necessary sensitivity, and you cannot develop your sensitivity except by undergoing a long string of experiences.

In the early nineteenth century 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’.4

Humanism split into three main branches. The orthodox branch holds that each human being is a unique individual possessing a distinctive inner voice and a never-to-be-repeated series of experiences. Every human being is a singular ray of light that illuminates the world from a different perspective, and that adds colour, 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. The more liberty individuals enjoy, the more beautiful, rich and meaningful is the world. Due to this emphasis on liberty, the orthodox branch of humanism is known as ‘liberal humanism’ or simply as ‘liberalism’.fn2

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. If all authority and meaning flows from individual experiences, how do you settle contradictions between different such experiences?

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.

over the last few decades the life sciences have reached the conclusion that this liberal story is pure mythology.

intelligence is mandatory but consciousness is optional.

Humans have two basic types of abilities: physical and cognitive. As long as machines competed with us humans merely in physical abilities, there were countless cognitive tasks that humans performed better. So as machines took over purely manual jobs, humans focused on jobs requiring at least some cognitive skills. Yet what will happen once algorithms outperform us in remembering, analysing and recognising patterns?

Traditionally, life has been divided into two main parts: a period of learning followed by a period of working. Very soon this traditional model will become utterly obsolete, and the only way for humans to stay in the game will be to keep learning throughout their lives, and to reinvent themselves repeatedly. Many if not most humans may be unable to do so.

In the twenty-first century our personal data is probably the most valuable resource most humans still have to offer, and we are giving it to the tech giants in exchange for email services and funny cat videos.

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.6