Free Will: Compatibilism

Lately I’ve been reading about compatibilism with regard to free will. While I’ve considered free will before, especially in the context of determinism, I’ve never explored compatibilism, and I decided it was time I got around to checking it out.

What triggered my renewed interest was, firstly, the movie Arrival (and the short story on which it’s based), and secondly, the HBO series, Westworld. Both have thoughtful science fiction with themes concerning free will (or its lack).

When one of my favorite physics bloggers, Sabine Hossenfelder, wrote a post about free will, it inspired me to write one, too. Monkey see, monkey do!

Let me start with some key ideas and questions:

Free Will: Intuitively, the idea that we can choose our actions without being in any way forced. Literally the idea that our wills are free.

Intuitively is a good start, but defining it more precisely is difficult. Yet a clear definition is central to the discussion; everything revolves around it. And it turns out that compatibilism largely depends on definitions of free will.

Causal Determination: The idea that the universe is a predictable machine and there is a chain of causality for every event. Nothing happens randomly or accidentally. There is never any such a thing as a “choice.”

This differs from behavioral or social determination, which is about human or animal behavior. This is a milder form of determinism — humans can choose to go against their nature.

Compatibilism: The idea that free will can still be defined in a causally determined universe (which seems contrary to the lack of true choice, but hence the importance of defining what is meant by “free will”).


Why is it important? Free will is necessary for moral responsibility. If every action is fully determined by the past, we are not the “drivers” of ourselves, we’re “passengers” — mere observers to the machine’s actions.

What’s the problem? If (causal) determination is true — and science thinks it is — then free will and morality cannot exist in their common sense. There is no such thing as choice, therefore no free will, and therefore no morality.


At this point it’s common to object that this is all very silly because of course there’s choice! Obviously! Life is a constant series of choices!


Not according to science, at least not at a reductionist level. (And if choice exists at an emergent level, how does it work its way back down?)

There’s a double-edged blade here:

¶ On the one hand, classical physics is fully deterministic. Nothing random happens in classical physics. Which means choice is impossible. Clocks can’t choose the next minute to display. Pool balls can’t choose where to go.

¶ On the other hand, quantum physics at least seems to have a truly random aspect, but random choices aren’t free choices, either. We don’t flip a coin to make decisions. Not usually.

So down at a physics level, it’s either clockwork or randomness, and we rarely, if ever, see that randomness higher up the chain. Quantum effects are notoriously swamped out by the larger world.

Which leaves the clockwork, and the physical world does seem to work on entirely predictable clockwork, from the orbits of planets to the chemical reactions of batteries. Above the quantum level, the physics world seems fully deterministic.


And chaos won’t help you. That’s a hard no. Chaos is fully determined. (Pun delightful to me and fully intended.)

Chaotic systems evolve entirely predictably. The problem is their futures can’t be calculated long-term with models. Calculations require numbers; numbers are necessarily rounded off; rounding off means chaos intrudes and destroys the calculation.

But the chaotic system knows what it’s doing and evolves according to its own clockwork. Given two identical chaotic systems, they will always reach the same states.

(As an example, the Mandelbrot, a most famous chaotic system, is always the same every time it’s generated.)


Bottom line: Science — so far! — sees no mechanism for free will.

Which seems to mean our everyday intuitive sense of free will is some kind of illusion.

I think the idea that a key aspect of our existence is an illusion with presumably no effect on our lives might be a red flag that something is off here. That gut reaction I mentioned — what if that’s a correct reaction?

Of course, our gut and our intuition are frequently wrong, but it’s a data point I find worth keeping in mind. We make decisions with what feels like free will; at the least, that needs explaining.


Enter compatibilism, which seeks to define free will in the context of determinism. Opposing it is incompatibilism, which asserts that free will and determinism cannot exist together.

Note that both start with the condition, “IF determinism is true…” Obviously, if the universe is not causally determined, this is all a moot point.

Many object, and I appreciate the objection, that compatibilism merely plays word games with the idea of free will. The incompatibilist view of mutual exclusion seems more factual.

But there is good reason to consider compatibilism, because it allows moral responsibility. If free will can be defined even in the context of determinism, then we are responsible for those free choices.

A key point here again is that it feels like we have free choice, so it seems logical we should act as though we do. Call that pragmatic compatibilism.


One thing that makes this conversation a bit ironic is that, if causal determination is true, which seems the case, then this post, every discussion, every thought, idea, or decision, on this and every other thing, is also fully determined.

Think of us all as characters in a movie or book. We may agonize over our decisions, but in the next scene or chapter we do the same thing each time. The characters in a story have no choice, only the illusion of choice.

It is the sense of being just a character in a story that makes people resist the idea. We’re convinced we have agency, yet those story characters would say the same thing.

Of course we’re real. Of course we choose our actions.


I don’t find much value in compatibilism. It does seem like word games to me. In its pragmatic approach, it seems to dodge the deeper question: Does causal determinism apply to consciousness?

Accept that it does apply to the classical physical universe, but ask whether consciousness is special enough to be non-deterministic.

And, if so, how might we discover that?

I’ll give you the punchline: I think the human mind, in virtue of how it works, just might be non-deterministic. And I don’t mean because of quantum effects (randomness doesn’t solve anything). I think it has to do with our ability to imagine futures and pick among them.


There is a related problem that I think might apply here: How do our mental states manage to affect our physical states?

It’s easier (although we’re not entirely clear on this, either)  to see how our physical states affect our mental ones: We look at red, we experience red.

But how does my mental desire to move my arm translate to actually physically moving my arm? It’s a bit of a puzzle; one we haven’t solved.

However we have a key fact: Mental states (whatever they are) do affect physical states. Our will to move causes us to physically move.


We’re in the realm of the mind-body problem. What is the relationship between mind and brain? How does a brain give rise to a mind? How separate are the two?

A key aspect is the seeming immaterial nature of the mind. We experience redness when our brain processes red visual information from our eyes. We can record the neural processing, but the experience, or qualia, seems subjective. It seems to transcend the material.

It is this subjectivity and transcendence that makes a theory of consciousness the hard problem.

So just how “special” might high-level consciousness (as experienced by humans and maybe some animals) actually be?

In the past I’ve suggested that, absent a metaphysical basis (such as “god” or “karma”) for morality (which I believe grounds on a notion of equality), perhaps human consciousness serves as a foundation for moral law. If we’re not all equal as god’s children, perhaps we’re equal in sharing consciousness.

I’ve also argued (rather strongly and at length!) that consciousness can never result from an algorithm or simulated model. As with laser light, it can only arise from the action of specific materials in specific configurations (i.e. a brain, but possibly a synthetic one).

So possibly very special, is my point.


I’ve commented often on how art seems a marker of intelligence. It’s something only humans do (so far as we know). It’s a part of our imagination, a larger skill that also improves our tool-use and engineering.

We imagine how tools can be better. We imagine building a bridge or a rocket. We imagine things that we then create. This appears a unique skill. One we so far haven’t been able to imagine automating.

Correction: We can imagine it just fine (hence our pursuit of it). It’s pulling it off that’s been the challenge. The hard problem.

The key point here is how we imagine things that not only don’t yet exist, but which might not ever exist. Or even cannot exist.

We can imagine things we know cannot exist. We can imagine almost anything.


Suppose that powerful imagination is the seat of our free will?

Suppose a mind is a very noisy, yet finely balanced, highly complex system with lots of feedback (that keeps it balanced). The noise constantly presents random idea fragments, and those few that resonate with the moment-to-moment state of the mind get amplified, while the rest vanish like virtual particles.

Our imagination comes from this background, tuned by our experience and pattern matching ability. Ideas “spring to mind.” Literally. They bubble up from the depths of our mental noise floor.

Compare it to how we filter out one conversation in a crowd. We focus on what interests us at the moment.

Given that our minds certainly seem to affect our bodies, however they pull that off, it only requires the idea that a mind can freely choose among imagined futures to enable free will.


So for me, it boils down to how free or determined imagination is.

And as a non-material, subjective phenomenon, it seems possible to make an argument about finely balanced tipping points, perhaps assisted by noise that scrambles determinism.

Is it possible that our minds, in considering possible imagined futures and selecting among them, do make “free” choices?

We might be talking about a model based on ‘appeal in the moment.’ Compare it to flipping through your tunes or channels looking for one that appeals to your mood right now. Given multiple options, how determined is the choice?

When I decide to have soup for dinner, and then decide between clam chowder, minestrone, or chicken wild rice, was that really set in stone by the Big Bang?

Was the minute or so I spent thinking about it just a movie I was watching as a passenger?

Why does it not feel that way at all?

Why do I feel like the driver?

About Wyrd Smythe

The canonical fool on the hill watching the sunset and the rotation of the planet and thinking what he imagines are large thoughts. View all posts by Wyrd Smythe

3 responses to “Free Will: Compatibilism

  • Wyrd Smythe

    I think it boils down to three questions:

    1. Why do we ask questions?
    2. Why do we imagine?
    3. Why do we feel we have agency?

    If we are fully determined automatons, why do these things — questions, imagination, agency — exist? The same view that holds causal determination should also hold evolutionary reasons for these things, which as automatons, offer no apparent value. So why do they exist?

  • rung2diotimasladder

    These are legitimate questions: Does science take determinism as an established truth? Is it possible in science to prove determinism is not the case?

    Anyway, as I see it, of course we have free will! I can choose to do one thing or another. Science can’t determine what I’m going to do next….hahahahaha….

    • Wyrd Smythe

      Legit questions for me or just in general? 🙂

      Science does take causal determination as an established truth at the low level of physics. It is generally presumed true that determination persists in emergent systems that arise from the physics. (If we start at the top and work down to the physics level, it’s called reductionism, which science also tends to presume is true. A system is necessarily as determined as its parts.)

      I do think there might be wiggle room in the presumption about emergence (or reductionism). I’m not sure we’re certain emergent systems are as fully causally determined as presumed. The problem is that, so far, no one can even name a mechanism that would break that determination, let alone prove one.

      Possibly the randomness of quantum physics introduces an element of randomness to the macro world. But it’s still a jump getting from random behavior to free will. Or maybe it does. Remember the donkey stuck between two bales of hay? Maybe when faced with a truly equal choice, we do just mentally flip a coin. Maybe, in the end, that’s how I pick a soup.

      Something else that’s occurred to me is that it’s one thing to look at all the causes leading up to an effect and say, sure, I can see how all those causes created that effect. But it’s maybe another thing to insist that the effect must follow from those causes until it actually does. Maybe a random event can derail it. Or maybe an intelligent mind can derail it.

      And while I have no “how” mechanism to offer, I find myself increasingly believing that intelligent minds being the one non-determined thing in reality. (Well, non-causally-determined. Minds can be quite determined! 🙂 )

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