Understanding the Argument Against Free Will
If you asked me a few years ago what my opinion was on free will, I would have found it an odd question. What is there to talk about? Of course we have free will. Case closed.
I decide when I lift my arm. I decide what vacation to go on or when to tell the waiter, “that’s good”, on the alarming amount of Parmesan cheese for my pasta. I decide when to click on an article about free will. Our agency in decisions is as obvious as the fact that our head is connected to our body. What other option is there?
But as I started digesting the case against free will, everything started feeling uneasy. What if my entire life is predetermined, and it is only a complicated illusion that I am willing my own actions?
This question around free will is the ultimate thought experiment. As we’ll get into, there is no easy, definitive answer, but there is a compelling case for why it is potentially one of greatest gaps between how we think the world (and universe) works and how it really does.
To be clear, the question at hand isn't if our choices are more limited than we imagine. I think that’s clearly the case. Assuming we do have free will, our actions are certainly dramatically constrained by our genetics, our environment, the various internet algorithms hellbent on shaping our behavior, etc.
True free will is a binary option. You either have it or you don’t. A life that has free will but is fairly predictable in its broad strokes is of a completely different category than a life with no free will.
Philosophers and religious leaders have been arguing various aspects of free will since the dawn of arguing, so SPOILER ALERT, nothing will be settled in this article. Instead, the point is to understand arguments against free will, and why even with modern science in the mix, it’s a true conundrum.
Let’s start with one of the main concepts in the free will debate.
Determinism is the idea that everything has a prior state and that all effects have causes. The billiard cue ball is hit into the 9 ball, and the 9 ball goes into a corner pocket of a billiard table. The cue ball caused the 9 ball to go into the corner pocket. The prior state of the 9 ball was stationary on the billiard table. A causal chain can be formed for the 9 ball, all the way back to when the ball was manufactured.
This kind of cause and effect is intuitive for us and quite obvious. Less obvious but still intuitive is that we live in a physical universe that is bound by physical laws where near infinite causes are leading to near infinite effects on a constant basis. This means the smallest molecules all the way to the largest galaxies are all following the rules of physics, where the causal links are impossibly complicated, but nonetheless happening.
Believing the universe to be run by causal determinism is believing the universe to be a giant billiard table. When you take this to its logical conclusion, you arrive at the fact that with a fully deterministic universe, everything in the entire universe today can be linked causally all the way back to the Big Bang.
If you had perfect information about the state and motion of everything and unlimited computing power, you could theoretically perfectly predict the future of a deterministic system. We'll discuss in a bit why this is impossible, but let's pretend for a moment that it is.
With this superpower at hand, imagine the types of things you can predict. Imagine being able to look at a distant galaxy and being able to perfectly predict where all the stars and planets and gas clouds will be a thousand years from now. Feels realistic right? After all, you have perfect information and perfect computing power.
Now think about peering into the minds of everyone in your town. Can you imagine knowing exactly what everyone will be doing precisely 2:37 pm 897 days from now? Does this feel more unlikely? If you are uncomfortable with this being possible, it's probably because you feel there is something inherently unpredictable about humans. Our brains are not the same as galaxies, even if you have perfect knowledge and computing power. It's worth thinking about what you think that difference is.
Maybe you'd like to invoke religion, or the soul, as being the difference. This is the famous mind-body dualism. If that is your belief, would that mean that all of biology and the animal kingdom is bound by deterministic laws, but not us? At what point in our evolution did humans pass the threshold of having free will?
Or maybe biology itself inherently allows free will, and that anything alive is not fully bound by the same hard determine.
For people to have free will, would we need to be divorced from this endless game of effects having direct causes?
This is where compatibilism comes in. Most philosophers throughout history have had opinions on the question of free will, and many prominent ones such as David Hume, Thomas Hobbes, and most recently, Daniel Dennett, have championed the idea of there being no issue with free will existing in a deterministic universe.
If you believe in a fully deterministic universe, but also believe that this is not incompatible with the idea of free will, then you are probably a compatibilist. You find the ideas of hard determinism and free will compatible.
Daniel Dennett has written at length about his compatibilist views, and helpfully puts forth many of his arguments in one place with a lengthy response and counter-argument to Sam Harris (who is a hard determinist and thinks free will is an illusion). In this essay he sets up his compatabilist point of view:
Being caused means not being free—what could be more obvious? The compatibilists deny this; they have argued, for centuries if not millennia, that once you understand what free will really is (and must be, to sustain our sense of moral responsibility), you will see that free will can live comfortably with determinism—if determinism is what science eventually settles on.
He acknowledges that scientists tend to agree with Harris on the idea that there probably is no free will, but he pleads for us to not forget about the dead philosophers who have been writing about this for thousands of years, and the modern philosophers who currently mostly agree with the compatibilist view point.
My reading of the back and forth is that they are largely talking past each other. Dennett at one point argues that even if you "rewind the tape" of time that things could very well play out the exact same every time, and that this wouldn't contradict his point.
Here Dennett is using the example of someone playing the card game bridge and making a bad move:
But, comes the familiar rejoinder, if determinism is true and we rewound the tape of time and put you in exactly the same physical state, you’d ignore the six of clubs again. True, but so what? It does not show that you are not the agent you think you are. Contrast your competence at this moment with the “competence” of a robotic bridge-playing doll that always plays its highest card in the suit, no matter what the circumstances. It wasn’t free to choose the six, because it would play the ace whatever the circumstances were whereas if it occurred to you to play the six, you could do it, depending on the circumstances. Freedom involves the ability to have one’s choices influenced by changes in the world that matter under the circumstances. Not a perfect ability, but a reliable ability.
I think this is the crux of his argument. Dennett finds there to be a distinct difference between a person making the same decision over and over again when you rewind the universe, and a robot who is programmed to only make the one decision. The possibility of other options is what matters. There is a freedom in this, even if these other options are potentially never realized if you rewind the tape.
I can't quite wrap my head around how this argument makes the idea of free will and determinism compatible with each other.
To look at another one of Dennett’s arguments, in this video for Big Think he walks us through a thought experiment.
His argument is basically that it would be harmful to society for neuroscientists to continue to try to convince people that they have no free will. As someone in the comments says, “has a professional philosopher just made an appeal to consequences?” As we get into below, I agree that neuroscience isn’t able to have anything definitive to say about free will, but what he presents is not an actual argument for or against free will.
In the below episode of In Our Time, the panel of philosophers frame compatibilism as a way to rationalize free will and determinism together.
Since we cannot actually “rewind the tape”, what types of arguments are these neuroscientists making in their quest to convince people they don’t have free will?
THE NEUROSCIENCE OF FREE WILL
Science Mag describes the early neuroscience research of free will:
Neuroscience’s first and most famous encounter with free will occurred in 1983, when physiologist Benjamin Libet made a peculiar discovery. A brain signal called the readiness potential was known to precede self-initiated actions, such as raising a hand or spontaneously tapping a finger. Libet found the readiness potential starts to rise before people report they are aware of their decision to move. Many took that as a challenge to the existence of free will.
There have been many studies looking at this trick our brains play on us. This recent study showed that we are easily fooled into thinking we can sometimes predict when dots would appear on a computer screen (at a rate greater than chance), when in reality their brains simply changed the order of events without them realizing it.
This body of research is only going to grow. I fully expect continued results from neuroscience studies that show there are unconscious thoughts that precede and dictate our conscious actions.
The best this research can show is that our brains are complicated and we are unaware of how much of our decisions are already decided upon by our unconscious brain. This is fascinating and says a lot about human behavior, but I don't see it as a line of research that could ever definitively prove or disprove free will. It could help us become aware that we are not fully in control, but not being in as much control as we think we are is different than being pulled along in a literal predetermined path.
It is natural to think, well if I don’t have free will, then why bother? This would be fatalism, a common first reaction to ingesting the arguments against the existence of free will.
Within the In Our Times episode mentioned above, the philosophers frame fatalism as follows:
Fatalism is not trying during an interview because you think, "Why bother, it’s outside my control anyway." Determinism without fatalism is understanding that you still need to perform well on the job interview, even if some cosmic outsider could see what was already set to happen.
The actual future will forever be outside our knowledge, so we must act as if we have full control over which direction it goes into.
This is a strange concept. Let's pretend you learn that we all live a fully predetermined life. This knowledge doesn't really help you make decisions. It might make you feel less guilty about things in your past, but it doesn't guide you into any kind of obvious path forward. Fate doesn't literally pick you up and move you along. You still need to go about your life, so you might as well act as if you have an active role to play in what is about to happen.
Calvinism is a real world example of this mindset. It's a sect of Christianity that believes in predestination. God has chosen who will be saved ahead of time, and nothing anyone does in life changes their outcome. If they find salvation, it is because God had chosen them to do so before they were even born. If this is your belief system, would you just lay down and say, "Why bother?" No, you would live your life as if you were one of the saved ones because your soul is literally on the line.
PREDICTION AND CHAOS
Decoding the human brain is complicated, but we must be able to make long term predictions of other complex systems with the supercomputers of tomorrow, right? The unsettling truth is our ability to truly predict anything long-term is also hopelessly futile.
The idea of determinism is predicated on the idea that the Big Bang is essentially the first action in an endlessly causal chain, like a never ending Rube Goldberg machine. If everything is determined and follows natural law, it makes sense that you would be able to make predictions, just like you could by studying the initial conditions of one of these Rube Goldberg machines.
When it comes to predictions, chaos puts quite a wrench in things. Yes, think of Jeff Goldblum in Jurassic Park, when he explains that a drop of water on your hand will follow a different path every time, even if you place it in the exact same spot.
The idea of chaos is that an outcome within a complex system has sensitive dependence on initial conditions. This is where the idea of the butterfly effect came from, that a butterfly flapping its wings in Brazil could cause a tornado in Texas.
The story of chaos and the butterfly effect is detailed wonderfully in Chaos: Making a New Science by James Gleick (and undoubtedly read by Michael Crichton). It all started in 1960 when Edward Lorenz was running some computer simulations about the weather. He set his computer to re-run a weather simulation and left the office. Upon his return he found a different outcome and was initially confused. From Gleick:
Suddenly he realized the truth. There had been no malfunction. The problem lay in the numbers he had typed. In the computer’s memory, six decimal places were stored: .506127. On the printout, to save space, just three appeared: .506. Lorenz had entered the shorter, rounded-off numbers, assuming that the difference—one part in a thousand—was inconsequential.
The fact that very small changes to the initial conditions of the simulation were enough to cause completely different outcomes was surprising to Lorenz. The intuition for many of us is that small rounding decisions won’t make a dramatic impact on your outcome. For example, look at how scientists could track the trajectory of a ballistic missile. If they know its initial trajectory and speed, they could very accurately tell you its target. Knowing the actual speed of the missile to three decimal points instead of six is not going to change the prediction very much. So if you can predict the path of a missile, why not the path of a weather pattern?
The difference is that unlike a missile, weather is a nonlinear system that is incredibly hard to calculate. Gleick explains:
Nonlinearity means that the act of playing the game has a way of changing the rules. You cannot assign a constant importance to friction, because its importance depends on speed. Speed, in turn, depends on friction. That twisted changeability makes nonlinearity hard to calculate, but it also creates rich kinds of behavior that never occur in linear systems.
In addition to weather, water in a turbulent flow is a good example of a nonlinear system that is near impossible to predict. Gleick wrote this book in the late eighties, but this passage makes a strong point at how difficult these calculations are:
Using the nonlinear equations of fluid motion, the world’s fastest supercomputers were incapable of accurately tracking a turbulent flow of even a cubic centimeter for more than a few seconds.
All this is to say that it is incredibly difficult to predict the outcome of a nonlinear chaotic system. There becomes a point where it's literally impossible. With weather, we might assume that we just need better data, and therefore a better understanding of these initial conditions that predictions are so sensitively tied to.
Gleick dispels us of this hope:
The modern weather models work with a grid of points on the order of sixty miles apart, and even so, some starting data has to be guessed, since ground stations and satellites cannot see everywhere. But suppose the earth could be covered with sensors spaced one foot apart, rising at one-foot intervals all the way to the top of the atmosphere. Suppose every sensor gives perfectly accurate readings of temperature, pressure, humidity, and any other quantity a meteorologist would want. Precisely at noon an infinitely powerful computer takes all the data and calculates what will happen at each point at 12: 01, then 12: 02, then 12: 03… The computer will still be unable to predict whether Princeton, New Jersey, will have sun or rain on a day one month away.
So with unlimited computing power and impossibly accurate weather sensors literally everywhere all over the planet, we still wouldn’t get much better predictions than we currently have. Those little fluctuations between the sensors would be enough to ripple upwards into massive changes that couldn’t be predicted.
There is simply no way to have enough accurate data on any nonlinear system to produce a truly accurate and long term prediction. Supercomputers will increasingly be able to model complex systems down to the molecule level, but they won’t be able to predict real world systems effectively because we will never have precise enough real world starting conditions.
And as complicated as the global weather patterns are, each human brain is even more so.
The impossibility of fully predicting the actions of a human brain are because the brain is a complex, chaotic system. Chaos is fully deterministic, but effectively impossible for us to completely model. In addition to this, there could be true randomness within our brain, which would be an even harder distinction to detangle in our prediction efforts.
RANDOMNESS AND QUANTUM MECHANICS
This is where quantum mechanics enters the conversation. Our current understanding of quantum mechanics (or at least my understanding of the expert understanding) is that quantum events are truly random. This means that by their very nature they are not deterministic.
The big question is if quantum events reverberate up to the macro scale and have butterfly effects of their own. If you rewind the tape, and you see differences in outcome, how much can be pinned on the quantum realm?
In an episode of Daniel and Jorge Explain the Universe, Daniel Whiteson (a physicist) explains that photons, electrons, and protons are not deterministic, but with enough of them their probabilistic fluctuations average out.
Things on the quantum scale are impossibly small (photons, electrons, quarks, etc), and could very well be enough orders of magnitude removed from the macro world we live in that there is no butterfly effect. Unfortunately, once again, there is no way for us to know for sure if the indeterministic quantum would effect how things play out if you reset the universe.
Quantum mechanics is full of weird and non-intuitive physics, so Whiteson says he is unable to say either way how its effects are felt in day-to-day life.
In the scenario where quantum mechanics doesn't truly affect us, Daniel does have a genius loophole to ensure different outcomes when “rewinding the tape.” If you pin a decision you will make on the outcome of a quantum event, like when a radioactive particle will decay, you will effectively break free from any deterministic causal chain. Careful experiments can be set up to observe the outcome of a single quantum event, but this is different than the question of how often quantum events impact macro events.
But another way to look at the potential of quantum events or any other phenomena introducing true randomness is, so what? If you reset the universe and the only thing that allows for divergent paths is randomness, how is that any consolation for free will? Your outcomes could be as infinite as the amount of times you reset the universe, but this doesn’t say anything either way about how much you truly had an impact in the outcome.
THE POSSIBLE SCENARIOS OF RESETTING THE UNIVERSE
Ok, those all are the necessary concepts needed to build a thought experiment around what happens if you perfectly reset the universe over and over.
For the purposes of this thought experiment, let’s pretend we are in the movie Groundhog’s Day, where when you reset the clock, everything is exactly how it was last time. But in this experiment, instead of each reset happening with the alarm clock and taking place in one town, each reset of our clock starts back at the Big Bang and we are looking at the entire universe.
Scenario 1: Every time the universe resets the same exact thing happens. Every single molecule behaves in the same exact way, and the universe unfolds such that about 4.5 billion years ago the planet Earth forms in the Milky Way galaxy and life arises in the exact same way and all does the exact same stuff.
Reset the universe exactly to the same starting point and get the exact same result, every time.
Scenario 2: Same as scenario 1, but the only change in the whole universe when you reset it is when biology arises on Earth and any other planet with life. There is something about biology that sets it apart. Living things follow free will in varying degrees, with humans at the pinnacle. This means that with every reset of the universe, the macro scale stays exactly the same, but things go wildly different near the planets with life (allowing for the potential of other life out there) because of the butterfly effect. This means human life usually doesn't ever show up on the scene.
Maybe in one iteration of our universe reset, giant ants become the dominant species.
Each time, it would be a complete mystery what paths life would take, because of the freedom of will for life.
Scenario 3: Same as scenario 2, but humans are the only things that have free will. All life, including all bacteria, behaves exactly the same way with each universe reset, until humans arrive on the scene. We eventually evolve enough to spark free will, and this is what causes each reset to go in infinite forking paths from each other.
Maybe we should have ended in nuclear war by now.
Or maybe we develop UFO looking spaceships and end up destroying ourselves, instead of exploring the galaxy and freaking out other civilizations like we should (I promise I’m an optimist about humanity, these are just more fun to draw).
Scenario 4: Randomness in the universe causes each reset to be completely different. Quantum effects cause macro changes and chaos takes over and things go completely different every time. One time we get a universe where matter never forms at all. Another time it matter forms but the Milky Way doesn’t. With near unlimited resets, you never get a universe that looks like ours today. There are too many variables that need to line up for things to work out the same way it did for our universe.
Let’s say this is the universe we live in, but we only “rewind the tape” by decades or centuries, so that humans have a chance to fully be on the scene.
Scenario 4 with free will: Let’s say you go back to only yesterday and compare the two paths. At first, you might be surprised at how little seems different. We are enough of creatures of habit, that there is probably a lot of overlap in the things we say and do.
In the Loops episode of Radiolab, a woman has a rare condition where her memory fully resets every so often. The remarkable consistency in which her conversation would flow each time is an example of how we might tend to act the same way over and over, even with bona fide free will. Our genetics and experience are just that powerful for how we behave.
But sure enough, between randomness and the actual intervention of free will, these paths between the alternate realities would diverge quickly and irrevocably.
Thinking through this scenario is also an exercise in realizing a major sci-fiction trope. That going back in time to change something specific will have specific changes in an otherwise undisturbed alternate reality. This happens in almost every time travel movie, but think back to Avengers: Endgame, and the whole time heist story line. Every single one of the interactions they had would have, on their own, caused dramatic shifts to the present day. Remember, you only need the smallest changes to initial conditions in order for chaos to completely change a nonlinear system.
Scenario 4 without free will: If we went back a day ago but this time without free will, a divergence would also eventually happen. If any randomness creeps in, the small changes made to the initial conditions will have profound effects. The level of randomness will dictate how long it takes, but once the paths start diverging between the alternate realities, there is no going back.
So which scenario do you find to be most likely?
If you think we live in scenario 1, does that mean there definitely isn't any free will, or is there still room for determinism and free will like compabitilists believe?
If you think we live in scenario 3, and that the only thing that sets the universe apart each reset is humanity and our free will, then what is it about our brains that sets us apart from the rest of the physical universe?
And do you think science will ever give us a definitive answer? The problem with this is that the hallmark of good science is falsifiability, and free will is an impossible thing to test. If a theory can be tested, then it could potentially be falsified, and become a stronger and stronger theory as it withstands many such tests.
But what is a true scientific test of free will? As stated above, I believe neuroscience will make astounding advances over the next several decades, but being able to predict what you are thinking or might decide in the immediate future based on subconscious brain activity are not things that I feel truly test the idea of deterministic free will.
After listening to countless podcasts and reading many thoughts on the subject, I walk away with two main ideas:
The idea of free will is not truly falsifiable by science, so it will always be in the realm of philosophy.
Even if we believe that free will doesn't exist, it still makes sense to behave as if it does.
All of this is a fun extended thought experiment, so it's easy to circle back to, "Why does any of this matter?" The best single answer is criminal justice. It's important to think through these issues because it could have dramatic implications on how moral our punishments are.
If as a society we started believing that there is no free will, this would completely undermine our founding doctrines and system of law. How do you punish someone if they literally couldn't have acted in any other way?
Punishments and even prison would still be necessary in a world where nobody believed in free will, because even if a murderer couldn't have acted differently, we need to act as if we don't know the future (because we don't) and remove them from the rest of society.
This could increase our compassion and reduce our retributive tendencies.
This all leaves me with a way to move forward, regardless of what the truth is.
Act toward myself as if I do have free will, and be generous towards others as if they don’t.
Once you get interested in the question of free will and all the subjects that are tangential to it, you start seeing it mentioned everywhere. Below is a list of additional media if you are interested in this topic.
-The Podcast Brunch Club (like book club, but for podcasts), did a listening list around free will that had a great selection of podcasts, many of which are mentioned in the article above.
-Lapace’s demon is a published thought experiment from 1814 where determinism in the form we discuss first makes it on the scene.
-The YouTube channel, Veritasium, does an amazing job explaining the science behind the butterfly effect, and explains strange attractors in the most wonderful visual way, something we didn’t get to in the article.
-Sam Harris and Daniel Dennett argue about free will on Harris’s podcast:
-The idea of changing the future with the smallest tweak in the past is illustrated in the famous 1952 Ray Bradbury short story The Sound of Thunder. I won’t spoil it but it does involve a butterfly, which only adds to the meaning behind the butterfly effect as we use it in relation to chaos.
-A great conversation between physicist Leonard Mlodinow and Krista Tippett on her podcast, On Being. Mlodinow boils down the question of free will to if there are miracles or not. He says this would be the only explanation for how things might exist outside the fundamental laws of nature.
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