Homo Deus: A Brief History of Tomorrow

by Yuval Noah Harari

In ancient Babylon, when people faced a difficult dilemma they climbed to the top of the local temple in the darkness of night and observed the sky. The Babylonians believed that the stars control our fate and predict our future. By watching the stars the Babylonians decided whether to get married, plough the field and go to war. Their philosophical beliefs were translated into very practical procedures. Scriptural religions such as Judaism and Christianity told a different story: ‘The stars are lying. God, who created the stars, revealed the entire truth in the Bible. So stop observing the stars – read the Bible instead!’ This too was a practical recommendation. When people didn’t know whom to marry, what career to choose and whether to start a war, they read the Bible and followed its counsel. Next came the humanists, with an altogether new story: ‘Humans invented God, wrote the Bible and then interpreted it in a thousand different ways. So humans themselves are the source of all truth. You may read the Bible as an inspiring human creation, but you don’t have to. If you are facing any dilemma, just listen to yourself and follow your inner voice.’ Humanism then gave detailed practical instructions on how to listen to yourself, recommending things such as watching sunsets, reading Goethe, keeping a private diary, having heart-to-heart talks with a good friend and holding democratic elections.

Your feelings are the voice of millions of ancestors, each of whom managed to survive and reproduce in an unforgiving environment.

What’s the use of having democratic elections when the algorithms know how each person is going to vote, and when they also know the exact neurological reasons why one person votes Democrat while another votes Republican?

But where do these great algorithms come from? This is the mystery of Dataism. Just as according to Christianity we humans cannot understand God and His plan, so Dataism says the human brain cannot embrace the new master algorithms. At present, of course, the algorithms are mostly written by human hackers. Yet the really important algorithms – such as the Google search algorithm – are developed by huge teams. Each member understands just one part of the puzzle, and nobody really understands the algorithm as a whole. Moreover, with the rise of machine learning and artificial neural networks, more and more algorithms evolve independently, improving themselves and learning from their own mistakes. They analyse astronomical amounts of data, which no human can possibly encompass, and learn to recognise patterns and adopt strategies that escape the human mind. The seed algorithm may initially be developed by humans, but as it grows, it follows its own path, going where no human has gone before – and where no human can follow.

Dataism thereby threatens to do to Homo sapiens what Homo sapiens has done to all other animals. In the course of history humans have created a global network, and evaluated everything according to its function within the network. For thousands of years, this boosted human pride and prejudices. Since humans fulfilled the most important functions in the network, it was easy for us to take credit for the network’s achievements, and to see ourselves as the apex of creation. The lives and experiences of all other animals were undervalued, because they fulfilled far less important functions, and whenever an animal ceased to fulfil any function at all, it went extinct. However, once humans lose their functional importance to the network, we will discover that we are not the apex of creation after all. The yardsticks that we ourselves have enshrined will condemn us to join the mammoths and the Chinese river dolphins in oblivion. Looking back, humanity will turn out to be just a ripple within the cosmic data flow.

If we think in term of months, we had probably focus on immediate problems such as the turmoil in the Middle East, the refugee crisis in Europe and the slowing of the Chinese economy. If we think in terms of decades, then global warming, growing inequality and the disruption of the job market loom large. Yet if we take the really grand view of life, all other problems and developments are overshadowed by three interlinked processes: 1. Science is converging on an all-encompassing dogma, which says that organisms are algorithms, and life is data processing. 2. Intelligence is decoupling from consciousness. 3. Non-conscious but highly intelligent algorithms may soon know us better than we know ourselves. These three processes raise three key questions, which I hope will stick in your mind long after you have finished this book: 1. Are organisms really just algorithms, and is life really just data processing? 2. What’s more valuable – intelligence or consciousness? 3. What will happen to society, politics and daily life when non-conscious but highly intelligent algorithms know us better than we know ourselves?