Sapiens: A Brief History of Humankind

by Yuval Noah Harari

There is no proof that cultures that are beneficial to humans must inexorably succeed and spread, while less beneficial cultures disappear.

Ever more scholars see cultures as a kind of mental infection or parasite, with humans as its unwitting host. Organic parasites, such as viruses, live inside the body of their hosts.

According to this approach, cultures are not conspiracies concocted by some people in order to take advantage of others (as Marxists tend to think). Rather, cultures are mental parasites that emerge accidentally, and thereafter take advantage of all people infected by them.

This approach is sometimes called memetics. It assumes that, just as organic evolution is based on the replication of organic information units called ‘genes’, so cultural evolution is based on the replication of cultural information units called ‘memes’.1 Successful cultures are those that excel in reproducing their memes, irrespective of the costs and benefits to their human hosts.

But many of these same scholars adhere to memetics’ twin sister – postmodernism. Postmodernist thinkers speak about discourses rather than memes as the building blocks of culture.

Yet they too see cultures as propagating themselves with little regard for the benefit of humankind. For example, postmodernist thinkers describe nationalism as a deadly plague that spread throughout the world in the nineteenth and twentieth centuries, causing wars, oppression, hate and genocide.

No matter what you call it – game theory, postmodernism or memetics – the dynamics of history are not directed towards enhancing human well-being.

The typical premodern ruler gave money to priests, philosophers and poets in the hope that they would legitimise his rule and maintain the social order. He did not expect them to discover new medications, invent new weapons or stimulate economic growth.

The Scientific Revolution’s feedback loop. Science needs more than just research to make progress. It depends on the mutual reinforcement of science, politics and economics.

fact, things were never quite that simple. In every age, even the most pious and conservative, there were people who argued that there were important things of which their entire tradition was ignorant. Yet such people were usually marginalised or persecuted – or else they founded a new tradition and began arguing that they knew everything there is to know.

Modern-day science is a unique tradition of knowledge, inasmuch as it openly admits collective ignorance regarding the most important questions.

Our current assumption that we do not know everything, and that even the knowledge we possess is tentative, extends to the shared myths that enable millions of strangers to cooperate effectively.

If the evidence shows that many of those myths are doubtful, how can we hold society together? How can our communities, countries and international system function?

Modern culture has nevertheless been willing to embrace ignorance to a much greater degree than has any previous culture. One of the things that has made it possible for modern social orders to hold together is the spread of an almost religious belief in technology and in the methods of scientific research, which have replaced to some extent the belief in absolute truths.

Consequently, the dominant modern research method takes for granted the insufficiency of old knowledge. Instead of studying old traditions, emphasis is now placed on new observations and experiments. When present observation collides with past tradition, we give precedence to the observation.

Mere observations, however, are not knowledge. In order to understand the universe, we need to connect observations into comprehensive theories.

Earlier traditions usually formulated their theories in terms of stories. Modern science uses mathematics.

When traditional mythologies and scriptures laid down general laws, these were presented in narrative rather than mathematical form.

Henceforth, anyone who wished to understand and predict the movement of a cannonball or a planet simply had to make measurements of the object’s mass, direction and acceleration, and the forces acting on it. By inserting these numbers into Newton’s equations, the future position of the object could be predicted.

A new branch of mathematics was developed over the last 200 years to deal with the more complex aspects of reality: statistics.

One of these was Jacob Bernoulli’s Law of Large Numbers. Bernoulli had codified the principle that while it might be difficult to predict with certainty a single event, such as the death of a particular person, it was possible to predict with great accuracy the average outcome of many similar events.

While there are no equations that predict what kind of organism will evolve under a specific set of conditions, geneticists use probability calculations to compute the likelihood that a particular mutation will spread in a given population.

Similar probabilistic models have become central to economics, sociology, psychology, political science and the other social and natural sciences.

Throughout most of history, mathematics was an esoteric field that even educated people rarely studied seriously.

Today few students study rhetoric; logic is restricted to philosophy departments, and theology to seminaries. But more and more students are motivated – or forced – to study mathematics.

Confucius, Buddha, Jesus and Muhammad would have been bewildered if you told them that in order to understand the human mind and cure its illnesses you must first study statistics.

In 1620 Francis Bacon published a scientific manifesto titled The New Instrument. In it he argued that ‘knowledge is power’. The real test of ‘knowledge’ is not whether it is true, but whether it empowers us. Scientists usually assume that no theory is 100 per cent correct. Consequently, truth is a poor test for knowledge. The real test is utility. A theory that enables us to do new things constitutes knowledge.

In fact, the relationship between science and technology is a very recent phenomenon. Prior to 1500, science and technology were totally separate fields.

Here and there people did develop new technologies, but these were usually created by uneducated craftsmen using trial and error, not by scholars pursuing systematic scientific research.

Today many Americans believe that the solution to terrorism is technological rather than political.

Just give millions more to the nanotechnology industry, they believe, and the United States could send bionic spy-flies into every Afghan cave, Yemenite redoubt and North African encampment.

Allocate millions more to brain research, and every airport could be equipped with ultra-sophisticated FMRI scanners that could immediately recognise angry and hateful thoughts in people’s brains.

Yet to the best of our knowledge, gunpowder was invented accidentally, by Daoist alchemists searching for the elixir of life.

One might have thought that the Daoist alchemists would have made China master of the world. In fact, the Chinese used the new compound mainly for firecrackers.

Only in the fifteenth century – about 600 years after the invention of gunpowder – did cannons become a decisive factor on Afro-Asian battlefields.

Because it appeared at a time when neither kings, scholars, nor merchants thought that new military technology could save them or make them rich.

Until the Scientific Revolution most human cultures did not believe in progress.

They thought the golden age was in the past, and that the world was stagnant, if not deteriorating.

If even Muhammad, Jesus, Buddha and Confucius – who knew everything there is to know – were unable to abolish famine, disease, poverty and war from the world, how could we expect to do so?

Many faiths believed that some day a messiah would appear and end all wars, famines and even death itself. But the notion that humankind could do so by discovering new knowledge and inventing new tools was worse than ludicrous – it was hubris.

Poverty, sickness, wars, famines, old age and death itself were not the inevitable fate of humankind. They were simply the fruits of our ignorance.

A famous example is lightning. Many cultures believed that lightning was the hammer of an angry god, used to punish sinners. In the middle of the eighteenth century, in one of the most celebrated experiments in scientific history, Benjamin Franklin flew a kite during a lightning storm to test the hypothesis that lightning is simply an electric current. Franklin’s empirical observations, coupled with his knowledge about the qualities of electrical energy, enabled him to invent the lightning rod and disarm the gods.

Poverty is increasingly seen as a technical problem amenable to intervention. It’s common wisdom that policies based on the latest findings in agronomy, economics, medicine and sociology can eliminate poverty.

Throughout history, societies have suffered from two kinds of poverty: social poverty, which withholds from some people the opportunities available to others; and biological poverty, which puts the very lives of individuals at risk due to lack of food and shelter.

Disciples of progress do not share this defeatist attitude. For men of science, death is not an inevitable destiny, but merely a technical problem.

People die not because the gods decreed it, but due to various technical failures – a heart attack, cancer, an infection.

The youngest, Edward, was the first of the boys to survive the dangerous years of childhood, and at his father’s death he ascended the English throne as King Edward II. In other words, it took Eleanor sixteen tries to carry out the most fundamental mission of an English queen – to provide her husband with a male heir.

In its more poetic and desperate moments, nationalism promises that whoever dies for the nation will forever live in its collective memory. Yet this promise is so fuzzy that even most nationalists do not really know what to make of it.

But science is not an enterprise that takes place on some superior moral or spiritual plane above the rest of human activity. Like all other parts of our culture, it is shaped by economic, political and religious interests.

Most scientific studies are funded because somebody believes they can help attain some political, economic or religious goal.