Einstein, Schrodinger, and the reluctance to give up hard determinism

Ethan Siegel on his Starts With a Bang blog has an interesting review of Paul Halpern’s new book on Einstein and Schrodinger, and their refusal to allow the implications of quantum physics to dissuade them from idea that the universe is strictly deterministic.  It’s an interesting post and one that I recommend reading in full.  I may well have to read Halpern’s book.

English: Hydrogen in (3,0,0)-state.
English: Hydrogen in (3,0,0)-state. (Diagram credit: Wikipedia)

The idea that the universe is fully deterministic is one that many people hold on to tightly, even though science has made that view questionable since the 1920s.  Things that happen with a particular quantum particle, such as an electron, can’t be predicted.  We can only assign probabilities to particular outcomes.  It’s only with populations of vast number of those particles that we begin to be able to make predictions.  Determinism appears to be an emergent phenomenon.

Many strict determinists find comfort in the notion that since the uncertainties average out over large enough scales, that we leave quantum uncertainty behind as we go up to the macroscopic scale.  And we do, to some extent.  It’s why we can use innumerable physical laws to make predictions.  But quantum uncertainty does intrude in the macroscopic world.  The very fact that we can do experiments that tell us about it is proof of that.  The question is to what extent it bleeds into macroscopic reality in natural processes.

Even if it only does so in one in a trillion interactions, within the uncertainty involved in any scientific measurement, in complex dynamic systems, chaos theory shows that that one in a trillion outcome can snowball in time to make those complex dynamic systems unpredictable, even in principle.  This means that complex dynamic systems such as the weather, economies, the human mind, and even sufficiently advanced computer systems, may have behavior that will never be predictable, at least not completely.

In my experience, those that do hold on to strict determinism, either don’t understand the implications of quantum mechanics (I won’t accuse them of not understanding quantum mechanics itself since even experts like Richard Feynman never claimed to have that understanding), choose to ignore those implications, or they tightly grasp on to interpretations of quantum mechanics that supposedly preserve determinism, such as the MWI (Many World Interpretation).

While I personally see the MWI as a candidate for reality, I’ve never been particularly impressed by the idea that it preserves determinism.  What does it mean to say that reality is deterministic when everything possible happens, but we still can’t predict what we’ll observe, even in principle, along our subjective timeline?   I’m not convinced that deserves the name “determinism.”  It certainly isn’t very useful for predicting future observations.

Anyway, Siegel’s post is a reminder that we’re all human and fallible, including the geniuses who, sometimes despite themselves, have broken new ground that call into question our most fundamental assumptions about reality.  And that reality itself has no obligation to conform to our most ingrained expectations.

22 thoughts on “Einstein, Schrodinger, and the reluctance to give up hard determinism

  1. That book is on my reading list after reading Ethan’s review.
    As I get older, I wonder more and more whether the universe may be completely chaotic at its most fundamental level, and that the laws of quantum physics (the standard model) are emergent properties at length and time scales that are large compared with the layer below.


    1. The universe may be structure all the way down. I doubt it it’s complete chaos at the lowest layers though. There has to be something there for the patterns we observe to eventually emerge from.


  2. Please do not use diagrams as you did as eye candy. The uneducated take those diagrams literally. They think they are actual photographs for one and they will interpret the inner most circle as the nucleus when at that scale, the nucleus would not be visible.


  3. Determinism, which is nothing more than a belief in the reliability of cause and effect, gives us the hope of understanding and even significantly controlling events in the real world. All of science depends upon our universe operating in ways that might be discovered. Medicine, for example, seeks the causes of disease to prevent and cure them.

    So determinism is not an idle metaphysical concept that may or may not be true. It is the foundation of scientific research and discovery.

    The problems come when we start imagining implications that cannot hold water, like the implication that free will must somehow be impossible.

    We observe determinism to be a characteristic of the real world. We observe free will to be the process of us choosing for ourselves what we will do next. And we observe this process happening within our physical, deterministic universe.

    So what’s the problem? Obviously someone has made some kind of a mental error to find conflict where there is none.


    1. I think the issue is whether all phenomena, at least in principle, can be predicted when all the causes and effects are accounted for. Quantum mechanics and chaos theory throws a wrench into that idea. Certainly in the realm of macroscopic physics and chemistry, determinism reigns within the certainty of our measurements.

      But no measurement is infinitely certain. And within those uncertainties, we can’t rule out that quantum effects don’t “bleed” into higher layers like biology, meteorology, and lots of other ologies and sciences. Even if it doesn’t, the limitation of our measuring may forever makes complex dynamic systems unpredictable accept by approximation. Quantum mechanics may make that true in principle in addition to just in practice.

      Science is about taking the world as it lies before us. We always have to be careful not to impose out own ideologies and philosophies on observations. It’s too easy to ignore what doesn’t conform on those ideologies.

      You and I agree that determinism and free will aren’t bound together. But there are many who fiercely disagree.

      Liked by 1 person

  4. The confounding thing is that we don’t really see a mechanism by which quantum randomness enters the macro world. Chemistry — and so much of life is just chemistry — is fully deterministic. The forces of nature all act in deterministic ways. The evolution of the Schrödinger wave function is fully deterministic (up to the point of taking a measurement).

    Quantum randomness has been proposed for explaining free will, but so far no function of the brain seems to involve quantum effects. (We’re so far away from a complete understanding of the brain, though.)

    I agree it seems like a system this complex would reasonably experience some effect, perhaps, but nothing so far presents as a candidate.

    I’m with you: I’ve never been entirely comfortable with the MWI doing away with the apparent randomness of measurement by claiming all outcomes do occur. The outcome we got sure seems random!

    FWIW: Chaos theory is fully deterministic, but not predictable. I’m sure you know that, but it wasn’t clear in the article that chaos — itself — doesn’t add to indeterminacy except for effectively making prediction problematic (importantly, the underlying system is fully determined).


    1. “The confounding thing is that we don’t really see a mechanism by which quantum randomness enters the macro world.”
      Doesn’t it enter it every time we do the double slit or other quantum experiment? There’s been a lot of speculation that the big bang and subsequent large scale structure of the universe could have resulted from quantum fluctuations. More generally in nature, I agree that any effects would have to be unimaginably minute, within the margins of error of our closest measurements.

      I not sure how we can say with certitude that a system where chaos theory if a factor is deterministic. We can say that many of its elements are deterministic outside the margin of error of our measurements. But since its unpredictability comes from those margins of error snowballing, any minute indeterminism that is undetectable by those measurements can’t be ruled out.


      1. Hmmm. Suppose there is a degree of indeterminism. How would that change things? To the degree that causes no longer produce reliable effects, the self could no longer reliably carry out its will. And if the reliability of determining its own will is also jeopardized, the benefit of freedom to follow one’s will would be wasted. So increasing indeterminism would decrease freedom rather than enhance it.

        But I notice you’ve earlier used William James’ suggestion that indeterministic free will introduces novelty where deterministic inevitability makes people feel like they’re in a rut.

        I’m re-reading William James’ “Pragmatism”. It’s like a mental can-opener. He points out that determinists tend to be pessimists and those embracing free will tend to be optimists. He remarks upon how a man “takes his universe” as if he were taking his coffee.

        I’m an optimistic determinist. I hold that all events are deterministically inevitable, but that we are right in there choosing for ourselves what will become inevitable and what remains a mere possibility. The pessimist would see us only as effects of prior causes. The optimist sees us choosing among our prior influences to decide what seems best to us at this moment. And that choice is our will. And our action is the final responsible cause of what happens next. And there is no more free required than that for our will to be deemed free.

        Liked by 1 person

        1. For free will, I don’t think indeterminism changes anything. It’s not like the mind can take any credit or responsibility for any randomness that may creep in. In my view, free will remains a useful social concept. I see talk of physics in relation to it as a category mistake.

          I have to admit that I haven’t read William James, but I do have pragmatic tendencies. I’ve become progressively more cautious epistemically over the years, particularly toward metaphysical questions.

          Liked by 1 person

          1. William James had an MD but also taught psychology and philosophy at Harvard according to Wiki. He was a big influence on Bertrand Russell. His brother, Henry James was the novelist. Apparently William also wrote a book on free will called “The Will to Believe”, but I don’t think I’ve ever read that one. They also mention a lecture at Harvard on “The Dilemma of Determinism”, with this interesting quote:

            “Old-fashioned determinism was what we may call hard determinism. It did not shrink from such words as fatality, bondage of the will, necessitation, and the like. Nowadays, we have a soft determinism which abhors harsh words, and, repudiating fatality, necessity, and even predetermination, says that its real name is freedom; for freedom is only necessity understood, and bondage to the highest is identical with true freedom.”

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          2. You might like William James’ “Varieties of Religious Experience”. I’ve read almost all of his works at one point or another (and even visited his house in Boston), but this one kickstarted my fascination with him. I don’t remember being all that impressed with “A Pluralistic Universe.” I can’t remember how I felt about “Pragmatism,” but I must’ve enjoyed it since I kept reading his works. Still, “Varieties” towers above the rest (perhaps it’s just my interest in that subject, though). In it are a lot of 1st person accounts from people’s journals and letters describing their religious experiences. These are really interesting. I mean the book is filled with these, and when you read one after another, interesting patterns emerge. And James is one of those very readable philosophers. In this work in particular, he’s fairly nuanced in his approach and sympathetic to religion while keeping his focus on the broader project (which could have really amounted to a boring relativism). His main thesis—and I could have this wrong—is that there are different types of personalities and these are drawn to different types of religions and religious aspects depending on what they need. Often it’s to rectify some fault in themselves, other times it’s more a more philosophical need. He manages to do this without belittling any particular religious stance.

            Liked by 1 person

          3. No worries. It was interesting. And I’ve never been a topic fascist 🙂

            I think I actually have a copy of ‘Varieties’ which I picked up during my religious investigation phase several years ago, but I fear it didn’t hold my interest. I’m sure part of it was the 1902 style of writing. Maybe someday.

            Liked by 1 person

          4. Aw, well maybe someday. I guess I was absorbed in reading the German philosophers at the time, so W.J. seemed like a breath of fresh air, like picking up a beach read or something. It’s been a long time since I’ve read it. I wonder if I’d feel the same way about the writing style now.

            Liked by 1 person

      2. “I not sure how we can say with certitude that a system where chaos theory if a factor is deterministic.”

        The non-linear equations that exhibit chaos behavior are fully deterministic, so in that sense the system is, at least in so far as its behavior is governed by those equations.

        You’re suggesting that tiny quantum fluctuations might be enough to make the system undetermined as well as unpredictable.

        Could be, sounds possible. We haven’t seen evidence — any mechanism — for it so far, so as you say “unimaginably minute”.

        That’s what’s annoying. The physics looks deterministic at the macro level. It certainly seems so on the short scale. Those chaotic effects can take billions of cycles to become a factor, so while the overall evolution of the universe may feel the effect more strongly, we may not, even over a span of civilizations.

        At least on the scale of our lives it doesn’t seem like chaos theory or quantum theory get us out of determinism, but I think there are enough unanswered quantum questions to leave room for something.

        We just don’t know what that is, yet.

        (And, FTR, I’m not arguing determinism here! Just saying we don’t see a clear mechanism that gets us out of it, at least not on any useful scale.)


        1. “Strict Compatibilism” . That’s what I should call it. Or maybe “Hard Compatibilism”. There should be no reason to fear perfect determinism or universal inevitability so long as we are perfectly in there, deciding of our own perfectly free will what becomes inevitable.

          We are not separate from causation (nothing is), so we cannot be its victim. So long as it is actually us, deciding for ourselves what seems best and choosing for ourselves what we will do next, then we call it freedom and are in fact acting of our own free will.

          The scientist, observing the decider from the outside, could, “theoretically”, find the means of predicting a decider’s choice by increasing her knowledge of the decider’s thinking, beliefs, values, history, etc.

          The decider, observing himself from the inside, in the process of deliberately choosing, always begins with an uncertainty, where he does not know yet which option he will choose. He can say truthfully, “I could choose option A or I could choose option B. But I don’t know which I will choose yet”. Then he begins evaluating his options in terms of his own values, his own beliefs, his own reasons, his own previous experiences, until he becomes more certain which option is the best option. And then he decides. His choice becomes his will at that moment.

          One event. The exact same event in reality. But seen from two different perspectives. The observer, seeking to reliably find the causes of the the choice, observes an event determined by those causes. The decider, seeking to find what works best for him, freely evaluates options A and B in terms of who he really is and what he really thinks and feels, and, if no one forces the choice upon him, acts of his own free will.

          Is free will just an “illusion”? No. There is no illusion. The decider is, actually, in fact, making a decision for himself. And science is every day learning more about how that process is rooted in the physical structure of the brain. So the decision is really happening in the real world, and no one else is making that decision except the decider himself.

          Both determinism and free will are “strictly” true and in the “hardest” possible way.


        2. Ah, I misunderstood your comment above. Sorry. I thought you meant the underlying systems were deterministic, but you meant to degree of uncertainty, of chaos, is deterministic. I think that’s true, at least in principle.

          From what I’ve read, there are many systems in every day life that are effected by chaos theory. Examples I’ve read about include weather systems, economies, and population dynamics. Neuroscientist Michael Gazzaniga has written that the brain, as an analog system, may be an example as well.


          1. Yeah. A chaotic system is as determined as anything can be — modulo uncertainty. But uncertainty applies to everything, so effectively chaotic systems are as deterministic as we can say any system is. Undetermined and unpredictable are different things, obviously.

            Chaos just means we can’t model a system because that involves numbers and numbers involves measurements and measurements involves rounding off and rounding off means chaos wins.

            The canonical examples are, in fact, weather and economics. The equations that describe these exhibit chaotic behavior. Tiny input variations result in wildly different outputs.

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