You Won’t Read This
Quantum Physics, Scientific Fatalism, and the Fight for Free Will
Stop. Pause for a moment and reflect on the fact that you apparently have a choice to continue reading this post or not.
I knew you’d make a great choice. In fact, it was inevitable. You probably have a feeling that you could have chosen not to continue scrolling. You might think that choice was free, not being forced upon you — that you acted of your free will. But that is wrong. You do not possess free will — at least, not of that kind.
Imagine if we could somehow turn back time to the exact moment before your choice was made. Whatever desires or intentions you had at that moment constituted your will, and those caused you to scroll. That’s obvious — but you could have altered those desires and intentions to produce a different result, right? No. Those desires and intentions were caused by the moment immediately preceding them. You were not free to choose those either, and so on it goes.
In our hypothetical time travel scenario, you have stepped outside your body and are probably imagining willing your former self to hit the back button instead of scrolling. But they can’t because your current desires and intentions are not theirs then but rather yours now. For your former self, all the causes of your actions were set in place the moment before the choice was made. On the other hand, in our hypothetical situation, there are people, namely you and I, attempting to supervene — but in reality, there is no such thing. Your future you is not watching and directing you to good decisions. Besides, if that were the case, would you really be free?
The real trouble with the notion of free will suggesting one could have done otherwise is that it would necessarily lie outside the laws of physics. Descartes, a 17th-century French philosopher, introduced the concept of dualism. This philosophical perspective suggests that the mind and body are two fundamentally distinct entities, with the mind representing the non-material or non-physical aspects of human existence. According to this view, the mind is responsible for mental processes such as thinking, feeling, and experiencing, which seem ephemeral and don’t have a real physical presence. The mind directs the body, perhaps mediated through the brain, to carry out physical actions.
If we accept dualism, it may be possible to reconcile the idea of free will with the deterministic laws of physics. Since the mind is separate from the physical world, it can operate independently and make choices unaffected by the natural laws that govern the universe. In this sense, free will could exist even in a world where every physical event has a predetermined outcome.
However, modern scientific research has increasingly challenged this dualist view. Neuroscience, for example, has demonstrated that mental processes are rooted in the brain’s complex network of neurons. In this context, the mind is no longer considered a separate, non-physical entity but rather a product of the brain’s activity. This leads us to the conclusion that thoughts, decisions, and actions are all grounded in the material world, which our bodies and brains are clearly a part of. Thus, your mind, including your will, is subject to the same deterministic laws that govern everything else. If thoughts and decisions are just the results of a complex interplay of physical processes in the brain, which is certainly well beyond scientific consensus at this point, then we are bound by the laws of physics — we are not free.
Indeed, some philosophers, scientists, and celebrity authors have proposed that we should abandon the notion of free will altogether, embracing a deterministic worldview where every event, including our choices and actions, is the result of prior causes. This scientific fatalism asserts that free will is an illusion, and our subjective experience of making choices is simply a byproduct of the deterministic processes that govern the universe. Fatalism of any sort is associated with depressed resignation in the face of inevitability, but perhaps quantum physics can save us.
In 1927, Heisenberg introduced the uncertainty principle to quantum physics, which sparked a revolution in science. The short of it is that quantum physics suggests our world is not deterministic after all. Quantum physics, unlike classical physics, incorporates indeterminacy and probabilistic outcomes, at least at the microscopic level. Some argue that the indeterminacy in quantum physics supports a view closely related to dualism called libertarianism.
Whereas Descartes embraced determinism, libertarianism argues that the existence of free will implies that some events (like human choices) are not entirely determined by prior causes. In the standard interpretation of quantum physics, some events are indeed truly random, having no prior cause. In fact, right now, you can obtain a live stream of random numbers from a quantum physics lab at the Australian National University generated from the quantum vacuum. These are quantum coin tosses that are literally impossible to predict.
Yet, it is hard to believe these random numbers have anything to do with my choice to take a sip of coffee. Random events at the microscopic level do not seem to translate directly into meaningful freedom at the level of human experience. But wait. What if I commit to choosing an action depending on the outcome of a single quantum coin toss? I’ll take a sip of coffee using my left hand if the coin comes up heads, or I’ll use my right hand if it comes up tails. Heads. Left. Sip. What caused that? At first glance, it might appear as though the indeterminacy of quantum mechanics has now played a role in my choice to take a sip of coffee with my left hand.
But basing my action on a random quantum event has merely replaced one form of determinism with another. Instead of my decision being determined by prior causes, it is now determined by the outcome of the quantum coin toss. In this case, the randomness of the quantum event does not necessarily give me meaningful control over my decision, which is still dictated by external factors rather than my desires and intentions. While purely random events might be free of causal constraints, they leave no room for the will.
There are also interpretations of quantum physics that recover determinism, including the “many-worlds” and “pilot-wave” theories. In these theories, objects in the physical world obey deterministic laws, and the apparent randomness is due to our ignorance of their initial conditions. However, the ubiquity of random quantum events and the fact that they can be correlated over arbitrarily large distances means that the causal explanation for our choices must be traced back to the beginning of the universe. Some have called this superdeterminism, and others have called it a cosmic conspiracy.
Ultimately, randomness of any sort might be a red herring in the free will debate, so let’s ignore it and return to a deterministic universe. After all, many (some claim most) philosophers argue that even if our choices are determined by the laws of physics, we can still have a meaningful sense of agency and responsibility. This perspective, known as compatibilism, holds that free will is compatible with determinism and that our subjective experience of making choices is still significant, even if prior events ultimately determine those choices. Opponents will often charge compatibilists with a sort of linguistic goalpost shifting, claiming they have distorted the meaning of the term — a weak version is that we can still be considered free if we are acting in accordance with our desires and intentions, even if we can’t choose those. I usually get lost or bored at this point, so let’s get back to metaphysics because I think there is more that quantum physics can teach us about free will.
Agency in a Deterministic Universe
My approach to understanding free will in a deterministic universe is to consider the role of abstraction, model building, and simulation in our navigation of the world. Human beings have a unique ability to create mental models of reality, imagine different scenarios, and project themselves into hypothetical situations. This cognitive capacity allows us to perceive and navigate the world in ways that are not strictly bound by the underlying physical laws.
One way to make sense of this idea is to think of our mental models and simulations as stories we tell ourselves about the world. In these stories, we manipulate models of ourselves as characters with goals, desires, and intentions, making choices and facing the consequences. This actually necessitates a (mostly) deterministic universe in order for these stories to be useful — there is no sense in imagining future scenarios if the chain of causes and effects leading to a projected outcome is not realizable. In this way, determinism is not a barrier to free will but the catalyst that enables the only meaningful version of it we can have.
Quantum physics reminds us that our models of reality are, at best, approximations. It forces us to project images of ourselves into virtual worlds of potentiality. Each world contains a mechanism of cause and effect, allowing the protagonist of the story to control the world, supervening over the laws of physics. You, model builder, are truly free, unconstrained by the illusion because you are the illusion. Don’t just be the protagonist, though, be the hero — you have no other choice.