Yuval Harari - Homo Deus - A Brief History of Tomorrow

The last nail in freedom’s coffin is provided by the theory of evolution. Just as evolution cannot be squared with eternal souls, neither can it swallow the idea of free will. For if humans are free, how could natural selection have shaped them? According to the theory of evolution, all the choices animals make – whether of residence, food or mates – reflect their genetic code. If, thanks to its fit genes, an animal chooses to eat a nutritious mushroom and copulate with healthy and fertile mates, these genes pass on to the next generation. If, because of unfit genes, an animal chooses poisonous mushrooms and anaemic mates, these genes become extinct. However, if an animal ‘freely’ chooses what to eat and with whom to mate, then natural selection is left with nothing to work on.

When confronted with such scientific explanations, people often brush them aside, pointing out that they feel free, and that they act according to their own wishes and decisions. This is true. Humans act according to their desires. If by ‘free will’ you mean the ability to act according to your desires – then yes, humans have free will, and so do chimpanzees, dogs and parrots. When Polly wants a cracker, Polly eats a cracker. But the million-dollar question is not whether parrots and humans can act out their inner desires – the question is whether they can choose their desires in the first place . Why does Polly want a cracker rather than a cucumber? Why do I decide to kill my annoying neighbour instead of turning the other cheek? Why do I want to buy the red car rather than the black? Why do I prefer voting for the Conservatives rather than the Labour Party? I don’t choose any of these wishes. I feel a particular wish welling up within me because this is the feeling created by the biochemical processes in my brain. These processes might be deterministic or random, but not free.

You might reply that at least in the case of major decisions such as murdering a neighbour or electing a government, my choice does not reflect a momentary feeling, but a long and reasoned contemplation of weighty arguments. However, there are many possible trains of arguments I could follow, some of which will cause me to vote Conservative, others to vote Labour, and still others to vote UKIP or just stay at home. What makes me board one train of reasoning rather than another? In the Paddington of my brain, I may be compelled to get on a particular train of reasoning by deterministic processes, or I may embark at random. But I don’t ‘freely’ choose to think those thoughts that will make me vote Conservative.

These are not just hypotheses or philosophical speculations. Today we can use brain scanners to predict people’s desires and decisions well before they are aware of them. In one kind of experiment, people are placed within a huge brain scanner, holding a switch in each hand. They are asked to press one of the two switches whenever they feel like it. Scientists observing neural activity in the brain can predict which switch the person will press well before the person actually does so, and even before the person is aware of their own intention. Neural events in the brain indicating the person’s decision begin from a few hundred milliseconds to a few seconds before the person is aware of this choice. 2

The decision to press either the right or left switch certainly reflected the person’s choice. Yet it wasn’t a free choice. In fact, our belief in free will results from faulty logic. When a biochemical chain reaction makes me desire to press the right switch, I feel that I really want to press the right switch. And this is true. I really want to press it. Yet people erroneously jump to the conclusion that if I want to press it, I choose to want to. This is of course false. I don’t choose my desires. I only feel them, and act accordingly.

People nevertheless go on arguing about free will because even scientists all too often continue to use outdated theological concepts. Christian, Muslim and Jewish theologians debated for centuries the relations between the soul and the will. They assumed that every human has an internal inner essence – called the soul – which is my true self. They further maintained that this self possesses various desires, just as it possesses clothes, vehicles and houses. I allegedly choose my desires in the same way I choose my clothes, and my fate is determined according to these choices. If I choose good desires, I go to heaven. If I choose bad desires, I am sent to hell. The question then arose, how exactly do I choose my desires? Why, for example, did Eve desire to eat the forbidden fruit the snake offered her? Was this desire forced upon her? Did this desire just pop up within her by pure chance? Or did she choose it ‘freely’? If she didn’t choose it freely, why punish her for it?

However, once we accept that there is no soul, and that humans have no inner essence called ‘the self’, it no longer makes sense to ask, ‘How does the self choose its desires?’ It’s like asking a bachelor, ‘How does your wife choose her clothes?’ In reality, there is only a stream of consciousness, and desires arise and pass within this stream, but there is no permanent self who owns the desires, hence it is meaningless to ask whether I choose my desires deterministically, randomly or freely.

It may sound extremely complicated, but it is surprisingly easy to test this idea. Next time a thought pops up in your mind, stop and ask yourself: ‘Why did I think this particular thought? Did I decide a minute ago to think this thought, and only then did I think it? Or did it just arise in my mind, without my permission or instruction? If I am indeed the master of my thoughts and decisions, can I decide not to think about anything at all for the next sixty seconds?’ Just try, and see what happens.

Doubting free will is not just a philosophical exercise. It has practical implications. If organisms indeed lack free will, it implies we could manipulate and even control their desires using drugs, genetic engineering or direct brain stimulation.

If you want to see philosophy in action, pay a visit to a robo-rat laboratory. A robo-rat is a run-of-the-mill rat with a twist: scientists have implanted electrodes into the sensory and reward areas in the rat’s brain. This enables the scientists to manoeuvre the rat by remote control. After short training sessions, researchers have managed not only to make the rats turn left or right, but also to climb ladders, sniff around garbage piles, and do things that rats normally dislike, such as jumping from great heights. Armies and corporations show keen interest in the robo-rats, hoping they could prove useful in many tasks and situations. For example, robo-rats could help detect survivors trapped under collapsed buildings, locate bombs and booby traps, and map underground tunnels and caves.

Animal-welfare activists have voiced concern about the suffering such experiments inflict on the rats. Professor Sanjiv Talwar of the State University of New York, one of the leading robo-rat researchers, has dismissed these concerns, arguing that the rats actually enjoy the experiments. After all, explains Talwar, the rats ‘work for pleasure’ and when the electrodes stimulate the reward centre in their brain, ‘the rat feels Nirvana’. 3

To the best of our understanding, the rat doesn’t feel that somebody else controls her, and she doesn’t feel that she is being coerced to do something against her will. When Professor Talwar presses the remote control, the rat wants to move to the left, which is why she moves to the left. When the professor presses another switch, the rat wants to climb a ladder, which is why she climbs the ladder. After all, the rat’s desires are nothing but a pattern of firing neurons. What does it matter whether the neurons are firing because they are stimulated by other neurons, or because they are stimulated by transplanted electrodes connected to Professor Talwar’s remote control? If you asked the rat about it, she might well have told you, ‘Sure I have free will! Look, I want to turn left – and I turn left. I want to climb a ladder – and I climb a ladder. Doesn’t that prove that I have free will?’