📚 Book Notes: Homo Deus

Swapnil Agarwal
11 min readJun 17, 2020


Photo by NASA on Unsplash

Here are my notes from Homo Deus:

  1. The welfare system was originally planned in the interest of the nation rather than of needy individuals. When Otto von Bismarck pioneered state pensions and social security in late nineteenth-century Germany, his chief aim was to ensure the loyalty of the citizens rather than to increase their well-being. You fought for your country when you were eighteen, and paid your taxes when you were forty, because you counted on the state to take care of you when you were seventy.
  2. It appears that our happiness bangs against some mysterious glass ceiling that does not allow it to grow despite all our unprecedented accomplishments. Even if we provide free food for everybody, cure all diseases and ensure world peace, it won’t necessarily shatter that glass ceiling. Achieving real happiness is not going to be much easier than overcoming old age and death.
    The glass ceiling of happiness is held in place by two stout pillars, one psychological, the other biological. On the psychological level, happiness depends on expectations rather than objective conditions. We don’t become satisfied by leading a peaceful and prosperous existence. Rather, we become satisfied when reality matches our expectations. The bad news is that as conditions improve, expectations balloon. Dramatic improvements in conditions, as humankind has experienced in recent decades, translate into greater expectations rather than greater contentment. If we don’t do something about this, our future achievements too might leave us as dissatisfied as ever.
    On the biological level, both our expectations and our happiness are determined by our biochemistry, rather than by our economic, social or political situation. According to Epicurus, we are happy when we feel pleasant sensations and are free from unpleasant ones. Jeremy Bentham similarly maintained that nature gave dominion over man to two masters — pleasure and pain — and they alone determine everything we do, say and think. Bentham’s successor, John Stuart Mill, explained that happiness is nothing but pleasure and freedom from pain, and that beyond pleasure and pain there is no good and no evil. Anyone who tries to deduce good and evil from something else (such as the word of God, or the national interest) is fooling you, and perhaps fooling himself too.
  3. How many wolves live today in Germany, the land of the Grimm brothers, Little Red Riding Hood and the Big Bad Wolf? Less than a hundred. (And even these are mostly Polish wolves that stole over the border in recent years.) In contrast, Germany is home to 5 million domesticated dogs. Altogether about 200,000 wild wolves still roam the earth, but there are more than 400 million domesticated dogs. The world contains 40,000 lions compared to 600 million house cats; 900,000 African buffalo versus 1.5 billion domesticated cows; 50 million penguins and 20 billion chickens. Since 1970, despite growing ecological awareness, wildlife populations have halved (not that they were prospering in 1970). In 1980 there were 2 billion wild birds in Europe. In 2009 only 1.6 billion were left. In the same year, Europeans raised 1.9 billion chickens for meat and eggs.4 At present, more than 90 per cent of the large animals of the world (i.e. those weighing more than a few kilograms) are either humans or domesticated animals.
  4. The theory of relativity makes nobody angry, because it doesn’t contradict any of our cherished beliefs. Most people don’t care an iota whether space and time are absolute or relative. If you think it is possible to bend space and time, well, be my guest. Go ahead and bend them. What do I care? In contrast, Darwin has deprived us of our souls. If you really understand the theory of evolution, you understand that there is no soul. This is a terrifying thought not only to devout Christians and Muslims, but also to many secular people who don’t hold any clear religious dogma, but nevertheless want to believe that each human possesses an eternal individual essence that remains unchanged throughout life, and can survive even death intact.
    The literal meaning of the word ‘individual’ is ‘something that cannot be divided’. That I am an ‘in-dividual’ implies that my true self is a holistic entity rather than an assemblage of separate parts. This indivisible essence allegedly endures from one moment to the next without losing or absorbing anything. My body and brain undergo a constant process of change, as neurons fire, hormones flow and muscles contract. My personality, wishes and relationships never stand still, and may be completely transformed over years and decades. But underneath it all I remain the same person from birth to death — and hopefully beyond death as well.
  5. The Turing Test was invented in 1950 by the British mathematician Alan Turing, one of the fathers of the computer age. Turing was also a gay man in a period when homosexuality was illegal in Britain. In 1952 he was convicted of committing homosexual acts and forced to undergo chemical castration. Two years later he committed suicide. The Turing Test is simply a replication of a mundane test every gay man had to undergo in 1950 Britain: can you pass for a straight man? Turing knew from personal experience that it didn’t matter who you really were — it mattered only what others thought about you. According to Turing, in the future computers would be just like gay men in the 1950s. It won’t matter whether computers will actually be conscious or not. It will matter only what people think about it.
  6. Many business corporations also recognise animals as sentient beings, though paradoxically, this often exposes the animals to rather unpleasant laboratory tests. For example, pharmaceutical companies routinely use rats as experimental subjects in the development of antidepressants. According to one widely used protocol, you take a hundred rats (for statistical reliability) and place each rat inside a glass tube filled with water. The rats struggle again and again to climb out of the tubes, without success. After fifteen minutes most give up and stop moving. They just float in the tube, apathetic to their surroundings.
    You now take another hundred rats, throw them in, but fish them out of the tube after fourteen minutes, just before they are about to despair. You dry them, feed them, give them a little rest — and then throw them back in. The second time, most rats struggle for twenty minutes before calling it quits. Why the extra six minutes? Because the memory of past success triggers the release of some biochemical in the brain that gives the rats hope and delays the advent of despair. If we could only isolate this biochemical, we might use it as an antidepressant for humans. But numerous chemicals flood a rat’s brain at any given moment. How can we pinpoint the right one?
  7. Over those 20,000 years humankind moved from hunting mammoth with stone-tipped spears to exploring the solar system with spaceships not thanks to the evolution of more dexterous hands or bigger brains (our brains today seem actually to be smaller). Instead, the crucial factor in our conquest of the world was our ability to connect many humans to one another. Humans nowadays completely dominate the planet not because the individual human is far smarter and more nimble-fingered than the individual chimp or wolf, but because Homo sapiens is the only species on earth capable of cooperating flexibly in large numbers. Intelligence and toolmaking were obviously very important as well. But if humans had not learned to cooperate flexibly in large numbers, our crafty brains and deft hands would still be splitting flint stones rather than uranium atoms.
    If cooperation is the key, how come the ants and bees did not beat us to the nuclear bomb even though they learned to cooperate en masse millions of years before us? Because their cooperation lacks flexibility. Bees cooperate in very sophisticated ways, but they cannot reinvent their social system overnight. If a hive faces a new threat or a new opportunity, the bees cannot, for example, guillotine the queen and establish a republic.
  8. Farmers believed in stories about great gods. They built temples to their favourite god, held festivals in his honour, offered him sacrifices, and gave him lands, tithes and presents. In the first cities of ancient Sumer, about 6,000 years ago, the temples were not just centres of worship, but also the most important political and economic hubs. The Sumerian gods fulfilled a function analogous to modern brands and corporations. Today, corporations are fictional legal entities that own property, lend money, hire employees and initiate economic enterprises. In ancient Uruk, Lagash and Shurupak the gods functioned as legal entities that could own fields and slaves, give and receive loans, pay salaries and build dams and canals.
    Since the gods never died, and since they had no children to fight over their inheritance, they gathered more and more property and power. An increasing number of Sumerians found themselves employed by the gods, taking loans from the gods, tilling the gods’ lands and owing taxes and tithes to the gods. Just as in present-day San Francisco John is employed by Google while Mary works for Microsoft, so in ancient Uruk one person was employed by the great god Enki while his neighbour worked for the goddess Inanna. The temples of Enki and Inanna dominated the Uruk skyline, and their divine logos branded buildings, products and clothes. For the Sumerians, Enki and Inanna were as real as Google and Microsoft are real for us. Compared to their predecessors — the ghosts and spirits of the Stone Age — the Sumerian gods were very powerful entities.
    It goes without saying that the gods didn’t actually run their businesses, for the simple reason that they didn’t exist anywhere except in the human imagination. Day-to-day activities were managed by the temple priests (just as Google and Microsoft need to hire flesh-and-blood humans to manage their affairs). However, as the gods acquired more and more property and power, the priests could not cope. They may have represented the mighty sky god or the all-knowing earth goddess, but they themselves were fallible mortals. They had difficulty remembering all the lands belonging to the goddess Inanna, which of Inanna’s employees had received their salary already, which of the goddess’s tenants had failed to pay rent and what interest rate the goddess charged her debtors. This was one of the main reasons why in Sumer, like everywhere else around the world, human cooperation networks could not grow much even thousands of years after the Agricultural Revolution. There were no huge kingdoms, no extensive trade networks and no universal religions.
    This obstacle was finally removed about 5,000 years ago, when the Sumerians invented both writing and money. These Siamese twins — born to the same parents at the same time and in the same place — broke the data-processing limitations of the human brain. Writing and money made it possible to start collecting taxes from hundreds of thousands of people, to organise complex bureaucracies and to establish vast kingdoms. In Sumer these kingdoms were managed in the name of the gods by human priest-kings. In the neighbouring Nile Valley people went a step further, merging the priest-king with the god to create a living deity — pharaoh.
  9. When the Nazis overran France in the spring of 1940, much of its Jewish population tried to escape the country. In order to cross the border south, they needed visas to Spain and Portugal, and tens of thousands of Jews, along with many other refugees, besieged the Portuguese consulate in Bordeaux in a desperate attempt to get the life-saving piece of paper. The Portuguese government forbade its consuls in France to issue visas without prior approval from the Foreign Ministry, but the consul in Bordeaux, Aristides de Sousa Mendes, decided to disregard the order, throwing to the wind a thirty-year diplomatic career. As Nazi tanks were closing in on Bordeaux, Sousa Mendes and his team worked around the clock for ten days and nights, barely stopping to sleep, just issuing visas and stamping pieces of paper. Sousa Mendes issued thousands of visas before collapsing from exhaustion.
    The Portuguese government — which had little desire to accept any of these refugees — sent agents to escort the disobedient consul back home, and fired him from the foreign office. Yet officials who cared little for the plight of human beings nevertheless had deep respect for documents, and the visas Sousa Mendes issued against orders were respected by French, Spanish and Portuguese bureaucrats alike, spiriting up to 30,000 people out of the Nazi death trap. Sousa Mendes, armed with little more than a rubber stamp, was responsible for the largest rescue operation by a single individual during the Holocaust.
  10. The sanctity of written records often had far less positive effects. From 1958 to 1961 communist China undertook the Great Leap Forward, when Mao Zedong wished to rapidly turn China into a superpower. Mao ordered the doubling and tripling of agricultural production, using the surplus produce to finance ambitious industrial and military projects. Mao’s impossible demands made their way down the bureaucratic ladder, from the government offices in Beijing, through provincial administrators, all the way to the village headmen. The local officials, afraid of voicing any criticism and wishing to curry favour with their superiors, concocted imaginary reports of dramatic increases in agricultural output. As the fabricated numbers made their way up the bureaucratic hierarchy, each official only exaggerated them further, adding a zero here or there with a stroke of a pen.
    Consequently, in 1958 the Chinese government was told that annual grain production was 50 per cent more than it actually was. Believing the reports, the government sold millions of tons of rice to foreign countries in exchange for weapons and heavy machinery, assuming that enough was left to feed the Chinese population. The result was the worst famine in history and the death of tens of millions of Chinese.
  11. People feel bound by democratic elections only when they share a basic bond with most other voters. If the experience of other voters is alien to me, and if I believe they don’t understand my feelings and don’t care about my vital interests, then even if I am outvoted by a hundred to one, I have absolutely no reason to accept the verdict. Democratic elections usually work only within populations that have some prior common bond, such as shared religious beliefs and national myths. They are a method to settle disagreements between people who already agree on the basics.
  12. 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.
  13. Twentieth-century medicine benefited the masses because the twentieth century was the age of the masses. Twentieth-century armies needed millions of healthy soldiers, and the economy needed millions of healthy workers. Consequently, states established public health services to ensure the health and vigour of everyone. Our greatest medical achievements were the provision of mass-hygiene facilities, the campaigns of mass vaccinations and the overcoming of mass epidemics. The Japanese elite in 1914 had a vested interest in vaccinating the poor and building hospitals and sewage systems in the slums, because if they wanted Japan to be a strong nation with a strong army and a strong economy, they needed many millions of healthy soldiers and workers.
    But the age of the masses may be over, and with it the age of mass medicine. As human soldiers and workers give way to algorithms, at least some elites may conclude that there is no point in providing improved or even standard conditions of health for masses of useless poor people, and it is far more sensible to focus on upgrading a handful of superhumans beyond the norm.
  14. In the past, censorship worked by blocking the flow of information. In the twenty-first century, censorship works by flooding people with irrelevant information. People just don’t know what to pay attention to, and they often spend their time investigating and debating side issues. In ancient times having power meant having access to data. Today having power means knowing what to ignore.

If you liked the above content, I’d definitely recommend reading the whole book. 💯

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Swapnil Agarwal

Software Developer at Day | Aspiring Writer at Night