21 Lessons for the 21st Century

Yuval Noah Harari

"Humans think in stories rather than in facts, numbers, or equations, and the simpler the story, the better. Every person, group, and nation has its own tales and myths. But during the twentieth century the global elites in New York, London, Berlin, and Moscow formulated three grand stories that claimed to explain the whole past and to predict the future of the entire world: the fascist story, the communist story, and the liberal story."

p. 1

"Since humans are individuals, it is difficult to connect them to one another and to make sure that they are all up to date. In contrast, computers aren't individuals, and it is easy to integrate them into a single flexible network. What we are facing is not the replacement of millions of individual human workers by millions of individual robots and computers; rather, individual humans are likely to be replaced by an integrated network. When considering automation, therefore, it is wrong to compare the abilities of a single human driver to that of a single self-driving car, or of a single human doctor to that of a single AI doctor. Rather, we should compare the abilities of a collection of human individuals to the abilities of an integrated network."

p. 22

"Unfortunately, what was good for survival and reproduction in the African savannah a million years ago does not necessarily make for responsible behavior on twenty-first-century motorways. Distracted, angry, and anxious human drivers kill more than a million people in traffic accidents every year. We can send all our philosophers, prophets, and priests to preach ethics to these drivers, but on the road, mammalian emotions and savannah instincts will still take over. Consequently, seminarians in a rush will ignore people in distress, and drivers in a crisis will run over hapless pedestrians."

p. 58

"Well, maybe Tesla will just leave it to the market. Tesla could produce two models of the self-driving car: the Tesla Altruist and the Tesla Egoist. In an emergency, the Altruist sacrifices its owner to the greater good, whereas the Egoist does everything in its power to save its owner, even if it means killing the two kids. Customers will then be able to buy the car that best fits their favorite philosophical view. If more people buy the Tesla Egoist, you won't be able to blame Tesla for that. After all, the customer is always right."

p. 61

"This situation could get far worse. As explained in earlier chapters, the rise of AI might eliminate the economic value and political power of most humans. At the same time, improvements in biotechnology might make it possible to translate economic inequality into biological inequality. The superrich will finally have something really worthwhile to do with their stupendous wealth. While up until now they have only been able to buy little more than status symbols, soon they might be able to buy life itself. If new treatments for extending life and upgrading physical and cognitive abilities prove to be expensive, humankind might split into biological castes."

p. 75

"In ancient times land was the most important asset in the world, politics was a struggle to control land, if too much land became concentrated in too few hands, society split into aristocrats and commoners. In the modern era machines and factories became more important than land, and political struggles focused on controlling these vital means of production. If too many of the machines became concentrated in too few hands, society split into capitalists and proletarians. In the twenty-first century, however, asset, and politics will be a struggle to control the flow of data. If data becomes concentrated in too few hands, humankind will split into different species."

p. 77

"In order to make wise choices about the future of life we need to go way beyond the nationalist viewpoint and look at things from a global or even a cosmic perspective. Like the ancient tribes along the Nile River, all nations today live along a single global river of information, scientific discoveries, and technological inventions, which is the basis of our prosperity and also a threat to our existence. To regulate this global river, all nations should work together."

p. 125

"There is no contradiction between such globalism and patriotism. For patriotism isn't about hating foreigners. Patriotism is about taking care of your compatriots. And in the twenty-first century, in order to take good care of your compatriots, you must cooperate with foreigners. So good nationalists should now be globalists."

p. 128

"The root of this debate concerns the gap between personal timescale and collective timescale. From the viewpoint of human collectives, forty years is a short time. It is hard to expect society to fully absorb foreign groups within a few decades. Past civilizations that assimilated foreigners and made them equal citizens--such as imperial Rome, the Muslim caliphate, the Chinese empires, and the United States--all took centuries rather than decades to accomplish the transformation.


From a personal viewpoint, however, forty years can be an eternity. For a teenager born in France twenty years after her grandparents immigrated there, the journey from Algiers to Marseilles is ancient history. She was born here, all her friends were born here, she speaks French rather than Arabic, and she has never even been to Algeria. France is the only home she has ever known. And now people say to her it's not her home, and that she should go "back" to a place she never inhabited?"

p. 149

"Upon reflection, most people concede the existence of at least some significant differences between human cultures, in things ranging from sexual mores to political habits. How then should we treat these differences? Cultural relativists argue that difference doesn't imply hierarchy, and we should never prefer one culture over another. Humans may think and behave in various ways, but we should celebrate this diversity and give equal value to all beliefs and practices. Unfortunately, such broad-minded attitudes cannot stand the test of reality. Human diversity may be great when it comes to cuisine and poetry, but few would see witch-burning, infanticide, or slavery as fascinating human idiosyncrasies that should be protected against the encroachments of global capitalism and Coca-Colonialism."

p. 152

"Human stupidity is one of the most important forces in history, yet we often tend to discount it. Politicians, generals, and scholars treat the world as a great chess game, where every move follows careful rational calculation. This is correct up to a point. Few leaders in history have been mad in the narrow sense of the word, moving pawns and knights at random. Hideki Tojo, Sadam Hussein, and Kim Jong-Il had rational reasons for every move they played. The problem is that the world is far more complicated than a chessboard, and human rationality is not up to the task of really understanding it. For that reason even rational leaders frequently end up doing very stupid things."

p. 184

"Monotheism did little to improve the moral standards of humans--do you really think Muslims are inherently more ethical than Hindus just because Muslims are inherently more ethical than Hindus just because Muslims believe in a single god while Hindus believe in many gods? Were Christian conquistadores more ethical than pagan Native American tribes? What monotheism undoubtedly did was to make many people far more intolerant than before, thereby contributing to the spread of religious persecutions and holy wars. Polytheists found it perfectly acceptable that different people worshipped different gods and performed diverse rites and rituals. They rarely if ever fought, persecuted, or killed people just because of their religious beliefs. Monotheists, in contrast, believed that their God was the only god, and that He demanded universal obedience. Consequently, as Christianity and Islam spread around the world, so did the incidence of crusades, jihads, inquisitions, and religious discrimination."

p. 196

"Does God exist? That depends on which God you have in mind: the cosmic mystery, or the worldly lawgiver? Sometimes when people talk about God, they talk about a grand and awesome enigma, about which we know absolutely nothing. We invoke this mysterious God to explain the deepest riddles of the cosmos. Why is there something rather than nothing? What shaped the fundamental laws of physics? What is consciousness, and where does it come from? We do not know the answers to these questions, and we give our ignorance the grand name of God. The most fundamental characteristic of this mysterious God is that we cannot say anything concrete about Him. This is the God of the philosophers, the God we talk about when we sit around a campfire late at night and wonder what life is all about.


On other occasions people see God as a stern and worldly lawgiver about whom we know only too much. We know exactly what He thinks about fashion, food, sex, and politics, and we invoke this angry man in the sky to justify a million regulations, decrees, and conflicts, He gets upset when women wear short-sleeved shirts, when two men have sex with each other, or when teenagers masturbate. Some people say He does not like us to ever drink alcohol, whereas according to others He positively demands that we drink wine every Friday night or every Sunday morning. Entire libraries have been written to explain in the minutest details exactly what He wants and what He dislikes. The most fundamental characteristic of this worldly lawgiver is that we can say extremely concrete things about Him. This is the God of the Crusaders and jihadists, of the inquisitors, misogynists, and homophobes. This is the God we talk about when we stand around a burning pyre, hurling stones and abuses at the heretics being grilled there."

p. 202

"It takes a lot of courage to fight biases and oppressive regimes, but it takes even greater courage to admit ignorance and venture into the unknown. Secular education teaches us that if we don't know something, we shouldn't be afraid of acknowledging our ignorance and looking for new evidence. Even if we think we know something, we shouldn't be afraid of doubting our opinions and checking ourselves again. Many people are afraid of the unknown and want clear-cut answers for every question. Fear of the unknown can paralyze us more than any tyrant. People throughout history worried that unless we put all our faith in some set of absolute answers, human society would crumble. In fact, modern history has demonstrated that a society of courageous people willing to admit ignorance and raise difficult questions is usually not just more prosperous but also more peaceful than societies in which everyone must unquestioningly accept a single answer. People afraid of losing their truth tend to be more violent than people who are used to looking at the world from several different viewpoints. Questions you cannot answer are usually far better for you than answers you cannot question."

p. 213

"Worse still, great power inevitable distorts the truth. Power is all about changing reality rather than seeing it for what it is. When you have a hammer in your hand, everything looks like a nail; when you have great power in your hand, everything looks like an invitation to meddle. Even if you somehow overcome this urge, the people surrounding you will never forget the giant hammer you are holding. Anybody who talks with you will have a conscious or unconscious agenda, and therefore you can never have full faith in what they say. No sultan can ever trust his courtiers and underlings to tell him the truth."

p. 227

"As noted in an earlier chapter, perhaps the worst sin of present-day science fiction is that it tends to confuse intelligence with consciousness. As a result, it is overly concerned about a potential war between robots and humans, when in fact we need to fear a conflict between a small superhuman elite empowered by algorithms and a vast underclass of disempowered Homo sapiens. In thinking about the future of AI, Karl Marx is still a better guide than Steven Spielberg."

p. 253

"To survive and flourish in such a world, you will need a lot of mental flexibility and great reserves of emotional balance. You will have to repeatedly let go of some of what you know best, and learn to feel at home with the unknown. Unfortunately, teaching kids to embrace the unknown while maintaining their mental balance is far more difficult than teaching them an equation in physics or the causes of the First World War. You cannot learn resilience by reading a book or listening to a lecture. Teachers themselves usually lack the mental flexibility that the twenty-first century demands, since they themselves are the product of the old educational system."

p. 271

"This is of course a logical fallacy. If you suffer because of your belief in God or in the nation, that does not prove that your beliefs are true. Maybe you are just paying the price of your gullibility. However, most people don't like to admit that they are fools. Consequently, the more they sacrifice for a particular belief, the stronger their faith becomes. This is the mysterious alchemy of sacrifice."

p. 293

© Kyuwon Lee, 2020.