On Chemicals; or, Free Will

In a deterministic system, the same input always leads to the same output. This feature can be considered a result of the system’s following a set of laws. At a large scale, physical behavior is deterministic. Gravitation, electricity and magnetism, and the strong and weak nuclear forces govern the system. These rules, the four fundamental forces, seem to adequately outline the behavior of the universe. This essay is not about physics.

The human body is, to the extent anyone has so far observed, a deterministic system. The atoms that comprise a human behave like any other ordinary atoms. They happen to be arranged in a very particular way and exhibit peculiar behaviors, like reading, but they are just atoms. The atoms also invent religions to explain their existence and behaviors.

The study of how phenomena that we can name (movement, disease, etc.) emerge from these atoms spans biochemistry, physiology, and more. Across these fields, we can quite confidently explain mechanisms for the behaviors we observe. As you read, electrical signals are transmitted through the nerves of the eyes as sodium and potassium channels (themselves proteins which the biochemists can aptly explain) open and close in mindless – that is, purely chemical – synchrony. When electrical signals reach the muscles of the eyes, their charge frees calcium ions from the sarcolemmae of the muscle fibers. The ions bind to spaces on troponin, another protein, exposing sites for yet another protein, myosin, to bind. The chemical energy stored in adenosine triphosphate, ATP, is converted to mechanical energy, causing contraction of the muscle fiber as myosin unthinkingly changes conformation. Thus, the medial rectus muscle of your left eye and the lateral rectus muscle of your right eye will contract, pulling your view from left to right across these words. Electrical signals will be generated from the reflected light that hits the retinae, and these signals will travel back to the brain. By immensely more complex but similarly chemical means, your brain will interpret the words and, hopefully, enjoy them.

In this view, I suspect a widely accepted one among the scientifically literate, there is an interesting dilemma that I have noticed. This dilemma is the subject and title of this essay.

If I am to have free will, I suppose that means I ought to have control over my actions. Of course, there will be restrictions on these actions. That I cannot fly does not mean that I lack free will. But for an action I reasonably can perform – say, lifting my arm – I would like to be able to claim free will to perform it. I would like to claim that if I, at any time, choose to lift my arm, the choice will have been mine in some pure sense. That, to me, is a reasonable ask.

Of course, I can lift my arm. You must believe me, dear reader: I am doing it now. I can wait a few seconds and do it again, when I decide that I want to. At a glance, the will is mine. The dilemma, though, is troubling. Under our purely chemical view of the human body, I suspect that I cannot claim any free will at all. After all, there is nothing special about the atoms that comprise me. They simply do as they must according to the four fundamental forces, given their initial conditions and the conditions they encounter. Of course, the conditions they encounter are also a result of the four fundamental forces, coupled with the initial conditions of the universe. If we believe in the four fundamental forces and the determinism principle I claimed earlier, then every life that ever has been, every life that ever will be, and every action, inaction, and interaction in between have already been determined.¹

The optimistic poindexters in the audience will be all too quick to remind me that there are random events in physics. In nuclear decay of a beta-emitting sample of C-14, the time between emissions is, as far as we can tell, a truly random event. Some argue that there may be hidden rules and variables that we cannot uncover (or have not uncovered, depending on your version of the legend). Truly random events would discredit the determinism claim and seem to rescue us in some way. The bad news, still, is that my pure choice is probably not purely mine if it can be reduced to mere chemical reactions. Moreover, if I (this is “I” in the Cartesian sense) cannot influence the outcome of the universe at all, we should be praying only to those churches which deify nuclear decay.

So, what is to be done if we are to rescue free will? Unfortunately, the best I can do is to suggest the only solution I see. It is not a pretty one, not one I have much faith in. But, it is the only alternative that is apparent to me, ridiculous though it may be. If living creatures have some genuine life-force, one that can influence the chemical reactions that go on in our heads and thus the impacts we have on the world, then perhaps we preserve free will. Take it or leave it. I, for one, submit myself to the chemical reactions to come.

¹Recall my claim from “On Prediction”: “If we could model every atom in the universe, we might […] be able to predict the future of any person or place. But, since this problem is safely impossible by any measure, we can rest easy without any predictions of the sort.” What I mean by this is that, if we wish to keep track of every atom (or subatomic particle, for that matter) in the universe, we face a genuinely impossible task. Since information must always have a physical representation (even if in the physical mind of a person), any kind of computational model would be squarely impossible due to the requirement that we represent each particle with something physical. Even in a perfectly efficient representation, the RAM requirement would be exactly equal to all of the matter in the universe. I cannot imagine any kind of lossless compression scheme that would account for this. If anything, the computational model already exists – it is the universe itself – but the information it provides cannot be presented to us in any useful way because it is so sparse. If we could somehow create enough matter for this representation out of energy, and even if we could somehow isolate all of this new matter from interaction with the rest of the universe, one can imagine how we would run into the same problem when considering the energy representation. That is to say, even if the universe is deterministic, nobody can predict the outcome.