Here are my notes on Yuval Noah Harari’s book.

Disclaimer: The following notes present information solely extracted and reworked from the book, not personal thoughts or considerations.

Timeline

• 13.5 billion YA: Matter and energy appear. Beginning of physics. Atoms and molecules appear. Beginning of chemistry.
• 4.5 billion YA: Formation of planet Earth.
• 3.8 billion YA: Emergence of organisms. Beginning of biology.
• 6 million YA: Last common grandmother of humans and chimpanzees.
• 2.5 million YA: Evolution of the genus Homo in Africa. First stone tools.
• 2 million YA: Humans spread from Africa to Eurasia. Evolution of different human species.
• 500,000 YA: Neanderthals evolve in Europe and the Middle East.
• 300,000 YA: Daily usage of fire.
• 200,000 YA: Homo sapiens evolves in East Africa.
• 70,000 YA: The Cognitive Revolution. Beginning of history. Sapiens spread out of Africa.
• 45,000 YA: Sapiens settle Australia. Extinction of Australian megafauna.
• 30,000 YA: Extinction of Neanderthals.
• 16,000 YA: Sapiens settle America. Extinction of American megafauna.
• 13,000 YA: Extinction of Homo floresiensis. Homo sapiens the only surviving human species.
• 12,000 YA: The Agricultural Revolution.
• 5,000 YA: First kingdoms, script and money. Polytheistic religions.
• 4,250 YA: First empire – the Akkadian Empire of Sargon. Invention of coinage. The Persian Empire.
• 2,500 YA: Buddhism in India.
• 2,000 YA: Han Empire in China. Roman Empire in the Mediterranean. Christianity.
• 1,400 YA: Islam.
• 500 YA: The Scientific Revolution.
• 200 YA: The Industrial Revolution.

Introduction

A key fact about prehistoric humans is their insignificance as animals having no more influence on Earth than gorillas, fireflies, or jellyfish.

The common mistake is to picture human species as a linear progression like: Ergaster -> Erectus -> Neanderthals -> Sapiens. This narrative suggests the wrong idea that only one type of human existed at any given point and that all earlier species were just older versions of us.

Humans’ rapid rise to the top of the food chain prevented the animal ecosystem from adapting as it had for other species in the past. This instilled insecurity and fear in humans, making them cruel and dangerous.

Interbreeding theory: when Homo Sapiens spread into Neanderthal territories, they interbred with Neanderthals until the two populations merged (and so on for other species).

Replacement theory: different human species were neither sexually attracted nor capable of reproducing with each other: over time, the others became extinct, leaving Homo sapiens as the sole survivors.

The Cognitive Revolution

The earliest Homo Sapiens failed to thrive, even losing out to Neanderthals. Around 70,000 years ago, a crucial shift took place with Sapiens discovering Australia and creating the first boats, oil lamps, bows, etc.

The first forms of religion, trade, and social stratification also began to emerge: academics associate this turning point with a leap forward in the cognitive abilities of Homo sapiens.

Gossip theory: our language evolved primarily due to gossip. With the cognitive revolution, humans began to transmit information that is not entirely real but imaginary such as legends, mythologies, gods, and religions.

Critical threshold: it highlights the challenge of keeping cohesion in a social group of more than 150 individuals. This limit was overcome by the advent of mythologies and religions: these large-scale shared belief systems allowed thousands, if not millions, to cooperate effectively towards a common purpose.

The curtain of silence: we have no evidence of the social stratification of ancient foragers: we know their tools and their remains but we cannot deduce all the social aspects that characterized them.

The Agricultural Revolution

Around 10,000 years ago, humans began to manipulate the lives of some animal and plant species: they began planting seeds, watering plants, herding sheep and so on.

One of the most compelling provocations: wheat was able to manipulate humans, and not vice versa. For millennia, this plant existed only in a small area of the world, while today it occupies an area 10 times the size of Great Britain. Moreover, humans began to expend much more effort cultivating and protecting this plant than procuring food by hunting.

The agricultural revolution enabled human population growth at the cost of a decline in living standards: this is due to the view of evolutionary success prioritizes the multiplication of a species as much as possible, regardless of the quality of its existence.

Was the agricultural revolution a miscalculation or a deliberate choice by humans who consciously chose to sacrifice quality of life to achieve specific goals?

Imaginary order

Imaginary orders (such as religions, capitalism, human rights, etc.) exist only in our minds and also influence our actions and desires: most people fail to realize or admit this because they are now been ‘normalized’ by our society, which has given them an appearance of reality. Imagined orders are inter-subjective phenomena.

Not all orders are imaginary in nature. Bees, for instance, possess an order encoded in their DNA: an individual bee is destined from birth to be either a queen or a worker. A queen will never perform worker tasks and a worker will never aspire to become a queen. Bees do not need lawyers or judges because their order is natural.

Nothing is unnatural as it is permitted by nature. Something unnatural simply does not exist (e.g. a human running faster than the speed of light).

The unification of humankind

Human history tends towards unification in the long run. It’s easy to observe how – over the millennia – humanity has transitioned from many “micro-worlds” that coexisted independently to a single more and more interconnected world.

Economic system: money is probably the most powerful imagined order that has allowed the entire human species to conform to a single large economic system.

Political system: the spread of empires – the most enduring political structure in history – has contributed to a significant loss of diversity among the world’s peoples.

Religious system: imagined orders are inherently unstable. Religion has contributed to maintaining their stability thanks to the presence of “absolute entities” that dictated laws to be followed and that everyone respected.

From religion to ideology

Over the past 300 years, religions based on the existence of gods have lost power in favor of those based on ideologies (communism, capitalism, nationalism, etc.).

They are called humanist religions. Liberalism – for example – places man at the center introducing human rights, which are essential for every individual.

History provides no evidence that its contingent developments have necessarily benefited humanity, or that only beneficial cultures have persisted.

Cultures often function as parasites, prioritizing their own propagation rather than the well-being of the human societies that carry them.

The Scientific Revolution

Over the past 500 years, humankind has increasingly come to believe in the capacity to increase their power through scientific research.

The scientific revolution is based on three aspects:

1. The recognition of human ignorance and the acceptance that currently held assumptions are subject to confirmation or refutation through new evidence;
2. Knowledge derives from observation combined with mathematical calculations for the creation of new theories;
3. Theories lead to the acquisition of new powers and technologies.

The difference between science and religion lies precisely in knowledge: in religion there are no mysteries or unanswered questions because it is the bearer of absolute truth; in science everything is questioned until new evidence emerges.

In the past, there was no belief in progress: everyone thought that the golden age belonged to times long gone and that things could only get worse.

The idea that humans could address global issues was inconceivable, as even divine intervention was considered insufficient. With the beginning of scientific progress, more and more people changed their minds.

The birth of capitalism and consumerism

The engine of this economic, scientific, and technological development is called capitalism: having limited resources, not all research could be financed.

The advent of banking revolutionized this: it became possible to finance nascent ventures based on projections of future success, with the expectation of repayment with interest.

At the same time, entrepreneurs also believe and trust that the banks will be solvent when they request their money in their accounts. Capitalism and this enormous economic growth are therefore based solely on trust in a future not yet written. The concept of credit spreads.

The continuous expansion of production gave rise to consumerism: more and more people were encouraged to buy things they didn’t really need.

In a short time, frugality became a defect thus confirming consumerism as the other side of the coin of capitalism – which together drive the modern economy.

Modern peace

Today’s peace, from a historical point of view, is incredibly rare and fascinating: never in history has there been such a long and global period of peace. Moreover, there has never been a period in which wars did not even exist in people’s common thinking (with the necessary exceptions).

Why does large-scale conflict seem so improbable in the present day? For two reasons: military (atomic) technologies are now so advanced as to prevent world conquest without mass suicide; the cost of wars is now so high as to mitigate their benefits – in Silicon Valley, modern value lies in the minds of FAANG engineers and not in gold mines.

This should not be interpreted as modern peace being immutable; on the contrary, humanity treads a fine line, subject to events that will determine the course of the future.

In search of happiness

Measuring happiness, which is an inner feeling, is not trivial: academics have therefore pursued the path of surveys asking people to rate various aspects to draw conclusions.

What has emerged is that material goods, particularly money, have an impact only up to a certain point beyond which social factors such as family and community become more significant.

Moreover, further investigation has revealed that real satisfaction is linked to what is desired at that precise moment. Therefore, when things are going well and expectations rise even significant improvements leave us dissatisfied; while when things are going badly, even small improvements can lead to happiness.

Aldous Huxley, on the other hand, in his theory where happiness equates to biological pleasure explains how the only way to maintain high happiness in the long term is to manipulate one’s biological system. This is because happiness is not caused by the context/good ‘x’ itself but by the chemical reaction of serotonin, dopamine and oxytocin.

Happiness is therefore a topic still to be fully defined for scientific research, which has only recently begun to pay more attention to it.