Christianity and Science, Science

Quantum Indeterminacy, Materialism, and Free Will: Do our minds shape reality?

The idea is that “freedom” of the will is simply the fact that human behavior is unpredictable, and that this unpredictability is a consequence of the random character of “quantum processes” happening in the brain… To be subject to random mental disturbance is not freedom but a kind of slavery or even madness. (Professor of Theoretical Particle Physics at the University of Delaware, Stephen Barr, 178)

Can there be free will on materialism?

The question has been perpetuated throughout the history of modern science. For quite a while, it was thought that all things were deterministic, given materialism. Thus, the view of life was a bit fatalistic. However, with the advent of Quantum Mechanics, some have argued that quantum indeterminacy allows for freedom of the will. Is that the case?

First, it’s important to outline quantum indeterminacy. On the quantum level, events are probabilistic. What that means is that “given complete information about the state of a physical system at one time, its later behavior [cannot] be predited with certainty… [only] the relative probabilities of various future outcomes [can be predicted]” (Barr, 176, cited below).

It becomes immediately apparent how some might see this as salvation for a physicalist perspective on free will. If events are not determined on a quantum level, perhaps our choices are free in some sense as well. But difficulties with this interpretation arise immediately. First, quantum indeterminacy is not a reflection of our choices, but just that: indeterminacy. As quoted above, our supposed choices would (on physicalism) be merely probabilistic. Our actions would be unpredictable, but that is not freedom. Surely, if the actions we take are merely the reflections of probability curves on a quantum level, that is not the same as freedom. Rather, they would be actions taken due to a basically random process. If I have the “choice” between A and B, and the probability is 50/50 on a quantum level, then my “choice” for B instead of A is just the same as if I flipped a coin. The coin doesn’t choose which side to land on, its just probability.

So it seems that right off the bat, quantum indeterminacy cannot explain free will on materialism or physicalism. Rather than being “free will” it would boil down to random events. As Barr wrote, we would be subject to random mental disturbances, and this would entail slavery at best (178).

But can materialists circumvent this problem? One suggestion is that we have control of quantum events themselves, so we therefore would be in control of our choices. But note that this presupposes a kind of extra-quantum center of control from which we can observe and control quantum events. Let’s put it into a thought experiment. Suppose we granted materialism. In that case, our “selves” are our brains. The brain is a physical object, itself governed by quantum events. Now, the purported way out for materialism is that our brain, a physical thing governed by physical processes, itself monitors and controls physical processes such that they effect the brain in the way the brain has chosen. The difficulties with this position should be immediately apparent. The brain, as a physical object, is itself governed by quantum events. These quantum events are not just logically prior but also temporally prior to the brain. Therefore, those things the brain chooses have been determined by previous physical states of affairs. So ultimately, it’s all material, and it’s all probabilistic. The freedom does not enter into the equation.

The problems don’t end there for those who wish to rescue freedom of the will in materialism. Another issue is that of the observer in a quantum event. In order for quantum indeterminacy to be helpful in regards to free will, the observer of a quantum event would have to be outside of the system. “[T]he observer cannot be considered part of the system that is being physically described and remain the observer of it” (Barr, 238). If all there is were the physical world, then the system would include “me.” I could not be the observer who took action in the quantum events, because I would be part of the description of these events. As Barr puts it:

The mathematical descriptions of the physical world given to us by quantum theory presuppose the existence of observers who lie outside those mathematical descriptions (238).

If materialism were true, then quantum indeterminacy could not rescue free will. The agents who were suppoed to be free would be, themselves, part of the system which they were supposed to observe and determine.

So does quantum indeterminacy factor into free will at all? Here’s where things get really interesting. It seems that those who argue for its importance with free will are correct, in a qualified sense. The indeterminacy provides a necessary, but not sufficient, reason for free will. We’ve already seen that it can’t help out in a purely materialistic world–the brain states which supposedly select from various choices are themselves physically determined by prior choices and/or other physical aspects of reality. But what if there were an immaterial mind in the mix? This immaterial mind would not be determined by prior quantum events, and indeed it could take the place of observer for quantum events. Thus, the immaterial mind could serve as the observer of these quantum events.

Quantum indeterminacy, then, acts as a necessary but not sufficient reason for freedom of the will. While the discovery of quantum indeterminacy ushered in an era in which comprehensive physical determinism was tempered by probability, it allowed an opening for free will which can only be utilized by an extra-physical observer. Because our experience of the world includes an intuitive sense of freedom, the previous arguments therefore provide a strong reason to embrace substance dualism. If we experience the world as one in which we are free, and we cannot be free on materialism, then our experience provides us with evidence against materialism.

The world, it seems, is more than merely the physical.


Stephen Barr, Modern Physics and Ancient Faith (Notre Dame, Indiana: University of Notre Dame, 2003).



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About J.W. Wartick

J.W. Wartick is a Lutheran, feminist, Christ-follower. A Science Fiction snob, Bonhoeffer fan, Paleontology fanboy and RPG nerd.


12 thoughts on “Quantum Indeterminacy, Materialism, and Free Will: Do our minds shape reality?

  1. Hi there! 🙂 I was just asking that question yesterday.

    Do we human beings have Freewill or not?
    The “To be, or not to be…” question
    has to be answerable as a matter of choice
    without us having to commit suicide to prove it.

    I’m voting for Freewill. This is why: The Bible says, God is love. In our minds, you can’t force another person to love you. Not even God can force us to love Him, but He knew that before He created us. He took a risk. Is the Law of Love therefore higher or more powerful than God? Our God who is love? It doesn’t say Love is God. We can learn to love Love, but we can’t learn to god God. My nonsense for today.

    Posted by Uncle Tree | November 7, 2011, 6:45 AM
  2. Great blog as always buddy!

    I guess, before I ask my question, I should preface by saying I’m ignorant to Materialist philosophy, would not call myself a Materialist, necessarily, (certainly not a reductionist one at any rate), and I think, for as much as I understand the above, I would agree with you (at least in the sense that indeterminacy doesn’t help the materialist’s notion of free will), so please keep in mind my question comes from a place of ignorance.

    You said: “Because our experience of the world includes an intuitive sense of freedom, the previous arguments therefore provide a strong reason to embrace substance dualism. If we experience the world as one in which we are free, and we cannot be free on materialism, then our experience provides us with evidence against materialism.”

    Reply: Wouldn’t the above Materialist notion of free will also include other modes such as compatibilism (even if the author you’re reviewing doesn’t)? Clearly stated I guess my question is: does compatibilism apply in this instance? If it does, have you ruled it out, and if you have, how so?

    Keep up the hard work!

    Posted by Rob Bezant | November 8, 2011, 1:15 AM
  3. I do not properly understood what free will is. At first glance it seems obvious, but as I look deeper, I find I understand it less and less.

    As I type this, my computer is deciding when to wrap the text on to the next line. It is making a decision based on its own rules of logic and external stimuli. Most people would say that it has no free will.

    This morning I chose what to have for breakfast. My choice was based on external stimuli (what was in the cupboard, the time I had available, what each choice tastes of, etc.), and (despite these ideas about quantum indterminancy) my choice wasa not random, but considered. Was I using free will? Most people say yes, I think (but I can see that you could argue that we only use free will occasionally; most choices are deterministic).

    If that was free will, how was it different to the computer? My thought processes were more complicated, but this is only a difference in degree, not a qualitative difference. My actions are more difficult (perhaps impossible in some cases) to predict. This is a consequence of the first, an emergent property perhaps. Is that free will? I would guess you would say no, so what actually is it?

    Posted by Pixie | November 8, 2011, 3:44 AM
  4. One problem I have with the stance of the lack of free will is it reduces to near-absurdity. I say “near” absurdity because it may not be a logical absurdity, but it’s definitely a pragmatic absurdity.

    Here’s an example. There has been a recent push to say that some criminals should not be convicted, because their actions were the result of their genes, and thus it was not their responsibility. Well, if that’s true, then perhaps the jury has no choice but to convict because their genes demand justice? Where is there deliberation in that?

    And it doesn’t stop there. If there is no free will, then why do I believe I have free will? Is it because my genes (or some other materialistic explanation) determined that I should? Whereas those that (correctly in this hypothetical case) believe we don’t have free will…it’s not because they arrived at that conclusion rationally, it was just dumb luck (they believe we have no free will because their genes/upbringing tells them so). This could be extended to ask bigger questions, such as, why do we think rationally about the universe? If our thinking is simply the result of external stimuli and the evolutionary history (sorry I’m smuggling in scientific notions to a topic that did not previously have them) of our species, then how in the world can we “know” that what we study about the universe corresponds to reality?

    In summary, I think “realization” that we don’t have free will would be, were it true, an awfully meaningful realization for creatures that have no ability to think for themselves.

    Posted by Greg Reeves | November 8, 2011, 10:37 PM
  5. the illusion of free will is not the same as free will, the fact that we think we are free is not at all an argument against materialism, not in the slightest.

    Posted by Ian | February 24, 2013, 11:40 PM
    • Your comment is not the result of your rationally working out that position, however. On your view, your comment was fully determined and therefore irrational. My comment, on your view, is equally irrational. But my view allows for rationality. The notion that free will is illusory makes reason an illusion.

      Posted by J.W. Wartick | February 24, 2013, 11:42 PM
      • I grant that if ‘free will’ is illusory then our ability to “reason” in some ways is likewise illusory, but it does not follow, as J.W. claims above, that ‘reason’ per se is illusory.
        The devil is in the detail: ‘reasoning’ qua “thinking” and/or “computation” does not require ‘free will’, else my computer would not be able to do it. More broadly, if ‘thinking’ be the machinations of axiom-based, rule-governed (logical or otherwise), data-manipulation processes – however they may be instantiated – then no such ‘thinking’ requires ‘free will’. As far as I can tell, causal determinism does not render logic irrational. Quite the contrary: causal determinism must obtain to the (possibly limited) extent that logically formal systems correctly describe the physical world.
        If ‘free will’ is illusory, then the only kind/s of “reason” that is/are likewise illusory is that which claims to transcend ‘thinking’ (qua computation) as defined above.
        So, the first challenge facing “free-willers” is to specify the characteristics of human “reasoning” that they claim transcend “computation”, and to show (in a non-hand-waving way) how such “reasoning” cannot possibly be performed by some sufficiently elaborate massively-paralleled network of multiple negative-feedback-regulated electrochemical process-engines comprising in excess of 100 trillion chemically-weighted functional amplifiers operating at 40 hertz and drawing 20 watts. (I doubt whether anyone – certainly not me, and likely not even J.W. – can fully apprehend the capabilities of such a machine, and thereby specify with any confidence what it could not possibly do.)
        The second challenge facing “free-willers” is to explain (also in a non-hand-waving way) how ‘substance dualism’ – to which J.W. appeals in his original article – might achieve what is being asked of it. Again, I grant that, if substance dualism were to obtain, then J.W.’s “extra-physical observers”, consciousness and even free will would all be a doddle! But this is a big “IF”. First, there can, by definition, be no physical evidence for any non-physical substance; and hence the only way to support a claim for its (non-physical) existence is via Modus Tollendo Tollens – i.e., by showing that physical causal determinism fails (which requires the violation of both Maupertuis’s Principle of Equipoise and Lagrange’s Principle of Least Action). And second, it remains an outstanding question how any non-physical entity (e.g., spirit or soul) might produce real, physical effects: in other words, to explain how ghosts that can walk through walls can rearrange furniture (but only when no one is watching), and/or how my immaterial ‘consciousness’ can make the neurotransmitters in my brain act “otherwise”.
        Until these various challenges are met, I am deterministically condemned to reject the notion of ‘Free Will’. As Jean-Paul Sartre said: “You may have free will, but you have no choice about it”.

        Posted by Tibor Molnar | May 22, 2016, 12:14 AM
  6. Good article. One small point is not clear (and a lot more could be said). The small point is that you say that QM supposes some kind of truly external observer that is outside the system.
    Now I don’t think you need this point for your argument. But since you like it, then tell me, how that could possibly be true in any QM experiment. There is one system and we are all part of it, materially. So how does the lab guy get separate from his QM apparatus. He his not separate and the moment he actually looks closely he changes the results. I think you should drop this point.

    Posted by Robert Aharon Lipschitz | December 25, 2014, 1:40 PM


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