Do we have free will?

What do two separate fields of science say regarding the existence of free will?
09 June 2016


We all believe that our lives revolve around choice. We believe we choose everything from our career to our lunch. But do we really have free will - did you choose to read this article, or was that 'choice' actually beyond your control? Scientists and philosophers have discussed the nature of free will for centuries, but much of the current debate comes from two areas of science in particular: physics and neuroscience.

Physics and the Free Will Debate

Many physicists argue that free will is merely an illusion. Although we think we make our own choices, the particles that make up our brains and bodies are simply acting in accordance to the laws of physics; this argument comes from the following logical progression:

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If we follow this chain back, we find that the laws of physics determine our choices. So how can we have free will? Are we not just puppets controlled by the laws of physics?

The influential physicist Einstein believed that the laws of physics control our choices. Because the motion of all observable particles follows a set of physical laws (Newton's laws), he believed that if we were to know the exact position and velocity of all of the particles in our brain, we could predict our behavior. He even believed that if we knew the position and velocity of all of the particles in the universe just after the Big Bang, we could predict the entire future of our universe. If Einstein were correct, the future of our universe would have been set in stone since the Big Bang.

But Einstein was wrong. He did not consider the behavior of tiny particles such as particles of light, which do not behave in a predictable manner. For example, sunglasses work by only letting in 50% of light particles (photons). When tiny photons travel toward sunglasses they have no idea whether they are going to pass through the glass or bounce off, they only 'choose' which path they are going to take when they come into contact with the glasses and they are forced to make a decision.


Their decision is entirely unpredictable. In contrast to what Einstein thought, knowing the position and velocity of photons and similar particles, would not enable us to predict their behavior. Therefore, even if we did know the exact position and velocity of particles after the Big Bang, and we had a super computer big enough to process all of this information, we could not predict the future of our universe, or even our future choices.

But does this give us free will?

No. It only means the future is not predictable. The fact that out choices are governed by unpredictable particle events does not really give us free will or control. So physics seems to suggest that although our future is not predictable, we do not make any choices about our future either. Perhaps this is where physicists should hand over to other disciplines such as neuroscience to explain why we appear to have free will.

Neuroscience and Free Will

Neuroscience's contribution to our understanding of free will began with Benjamin Libet in the 1980s. Libet demonstrated in a series of experiments that before the conscious intention to move you hand in an apparent act of fee will, your unconscious brain signals that this is what it wants to happen. In other words, your brain appears to decide to move your hand before you consciously think to do so. These results have been reproduced in many recent studies, suggesting that the conscious decision to move your hand is merely an afterthought of your controlling unconscious brain.

However, there are criticisms of such experiments, many scientists have called into question the accuracy of the measurement of the time at which a person makes a conscious decision - perhaps it occurs earlier than the experiments suggest. Or perhaps, the unconscious brain activity is not as important as we think; some subsequent studies have shown that unconscious brain activity only predicts movement with 70-80% accuracy.

It seems neuroscience allows more room for free will than physics. In fact, Libet himself believed that while free will might not exist in the conventional sense of the phrase, human beings might have the ability to veto decisions, giving us the choice to not carry out certain actions. Furthermore, Libet's findings only threaten free will when our unconscious brain activity is not seen to be an integral part of our existence; human brains do make decisions, but much of that decision-making occurs unconsciously by something other than our conscious selves. These arguments have lead to practices such as mindfulness, where you are encouraged to not judge yourself based on your thoughts (as these may not be within your control), but instead to observe your conscious thoughts non-judgmentally and let them go.

Many scientists are very unwilling to accept the idea that free will is entirely nonexistent. This is because our daily lives persistently reinforce a sense of free will; we find it hard to believe that we are being controlled by anything other than our conscious thought. It is so hard to accept that our personal experience might be faulty, even in light of physical laws and Libet's findings. Perhaps we are also reluctant to accept such a conclusion, as we are scared of the consequences it might bring. If as a species we believe our actions are not governed by our choices, might we behave more selfishly and irresponsibly? Should we blame criminals for their actions if their neurons just followed the laws of nature? Should we ever feel guilty?

We all believe that our lives revolve around our choices, but science may one day conclude that free will is merely an illusion. However, the debate is as strong today as it was centuries ago - perhaps science alone will never be able to answer this big question.


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