Warning, this article will assume some education on quantum mechanics. In fact it’s specifically for people who claim that quantum probability is both real and something that can help with a notion of “free will”. I expect those people to be familiar with some things, for example, the distinction between quantum mechanics and interpretations of quantum mechanics, what a wave function is, collapse of the wave function vs decoherence, and the like.If you aren’t at least somewhat familiar you can still read this, but be forewarned that many of the terms will not be unpacked in this article, as that would bloat it.
In this article I’m going to eventually disregard the logical incoherence of probability being “real” (or in philosophical terms “ontic”) and pretend that there is this magical type of event that is neither caused nor uncaused (in any appropriate conception of being uncaused)….but rather the event itself is, in actuality, probabilistic. A special third option (probabilistic) between two dichotomous events that are in opposition to each other (caused/uncaused).
First however, I will stress up front that this type of “realist” probability is illogical nonsense. I don’t just assert that it is, rather it can be shown. To understand why, read here (or pick up a copy of my book):
Ontic Probability Doesn’t Exist: Assessing “Probability” for the Free Will Debate
Some people look at a specific indeterministic interpretation of quantum mechanics, called the Copenhagen interpretation, and they believe that this interpretation says that where a particle ends up when the wave function collapses is probabilistic. In the sense that we can only assess a probability of where the particle will end up, they are correct.
But these people often say much more than this. For particles, they might claim, it isn’t simply that we don’t or can’t know where the particle will end up that induces the probability, but rather the probability is within the structure itself. The probability is real (ontic), rather than simply due to a lack of knowledge (epistemic).
There is nothing that causes the particle to a specific area, but at the same time it follows probabilistic rules that aren’t brought about by non-caused events that just pop into existence for no rhyme or reason. Either that or they say it is “non-caused” but at the same time probabilitic, two incompatible notions. In other words it’s “not caused” to be “weighted” for a specific output (which makes no sense).
Somehow, real probability is assessed. For simplicity sake we can split the target that the particle collapses at into two areas, one in which we assess a 70% probability and the other a 30% probability. In reality there is a whole range of probabilities that is assessed by specific equations (probability amplitude, Schrodinger equation, etc.), but we can keep the probability simplistic by partitioning the screen at two locations which we can assess a 70% for one part and a 30% for another.
What the person who claims that realist probability exists would claim is, if a particle ended up in the 70% area, it could have ended up at the 30% area. In other words, if we were to go back in time to when the particle was shot, a change could happen that brought it to the 30% area (it would have a 30% chance when we brought back that moment). And if we were to somehow keep going back in time to when the particle was shot, about 70% of the time it would end in one location, and 30% in the other. The probability itself is a real, ontological trait of the particle.
In my book I explain in detail why this cannot logically be the case, and why an acausal event would be needed to go to an otherwise situation – and how such an event would have no temporal or spatial determinacy making a 70/30 probability assessment impossible for it. Regardless of this in-depth case I have made against such truly incoherent notions, we have reached the point where I’m going to let all of that go! Give it up ‘Trick, and get on with a more important point!
For the sake of argument and the rest of this article, I’m going to allow for this absurd notion of logic defying “realist” probability, because some people seem to think that it would allow for free will. The fact of the matter, however, is that it doesn’t allow for free will anymore than a truly non-caused event allows for free will (which is not at all).
Sure, both realist probability and acausal events would allow for a “could have happened otherwise” assessment, but free will also requires that the otherwise that takes place would have in some way been “up to the chooser”.
The probabilistic nature of a quantum event isn’t something that would be “up to us”. We couldn’t decide if the event ended up in the 70% area or the 30% area – as whether it ends up in one over the other isn’t “caused” to end up in one over the other, and it’s certainly not caused by any decision we make. If it is, that other option was never a real possibility.
Some might say “but the particles that have the probability happen within me”. This, however, is irrelevant to whether or not the direction they take was “up to you”. Everything that makes up your genetic structure is within your “body” – that doesn’t imply you had a say in each of these things. For a probabilistic event that happens “in your body”, the very notion of this “real probability” of the event means that whether the event went to the 70% or the 30% (or any range of probability) is nothing that you are in any way controlling or can control. If you could weight the event in your favor you could bypass the inherent probability (but you cannot).
If you are hoping for the 70% chance, at least you can be happy that you have the greater odds. If you are hoping for the 30% chance, well your odds suck. Either way, if the switch of your decisions depends on quantum dice being rolled, you better hope that your desires and the higher percentages align. That will give you a better chance. Keep in mind that it is pure luck that what you want has a higher chance of happening than what you don’t want.
Also keep in mind that those very “wants” are susceptible to the same probability distributions. If probabilistic events have a say on your wants and desires, it’s the luck of the draw whether you’ll want to climb the tree to save the cat, or throw rocks at it.
Some might argue that a conscious person might “freely” play the odds of the probability statistic (under some strange, unrealistic world where they could map quantum probabilities to the influence of a specific decision), but this misses the point that their decision to play those very odds is also either dictated by causality or dictated by probabilistic events. If Billy asserts that he wants to play the quantum odds and was able to somehow know the probabilities for each of his “possible” outcomes, for him to play that one game rather than the other with a different distribution of events, he would have to make a decision between the two. The problem here, however, is that if such a decision between the two is also based on a probability distribution, Billy equally has no say over what game he will play.
To put this in other terms, imagine Billy is given two different die to roll, each that are weighted differently. Imagine Billy can choose to roll one die or the other. One is weighted in such a way that a 6 rolls more, and the other is weighted in such a way that a 2 rolls more. Now imagine that the 6 is what Billy wants (e.g. if he rolls a 6, the cat gets saved), but he does not want a 2 (which leads to rocks being thrown at the cat).
It may seem like Billy should play the die with the 6 that has the higher change. The problem is, the very decision to roll one die over the other is also not dictated by Billy but rather by another die roll (e.g. if Billy rolls a 4 he will roll the 6 weighted die next, if he rolls a 3 he will roll the other die next). And if you say that Billy has a choice over the weighted die he rolls in order to roll a 4 or 3 as more likely, then that choice too is based on a different roll of the die.
Each probabilistic event that happens Billy has no say over, and the causality that ensues from each event in the past either changes trajectory via another probabilistic event, or stays on causal path (no more free than determinism). There is no conscious freedom in any decision, and all changes that happen due to a roll of the probabilistic die are never willed events.
If you claim that quantum probabilism is your free will savior, it matters not what quantum interpretations you postulate, it just isn’t. For some interpretations such as a realist (meaning real worlds) many-worlds interpretation, the probabilism is even an illusion. This is because each event on the probability scale happens. From the perspective of an observer it seems like their results were probabilistic, but from the perspective of the entire “multiverse” each one of those events took place equally splitting off into different worlds. And every event had to take place. And though a many-worlds interpretation is entirely deterministic and each world couldn’t have been otherwise, if someone (incorrectly) postulated that indeterministic events were a part of each world taking place, those would equally be out of anyone’s control (it would also be irrelevant as each world would still have to take place the same way).
For truly indeterministic interpretations (such as Copenhagen), if “ontic probability” is inherent in the collapse of the wave function, then no person can be said to have any control over the results. It must follow the probabilistic rules of the wave itself.
If there really was such a thing as ontic probability, and if any one decision relied on any number of these events, I think they would be quite annoying. Rather than a conscious causal process leading to your decisions, you would have events that could happen in many different ways that would change your output based on “probabilistic luck”. It would be like each decision you make was based on the results of a Casino slot machine. And when and if you pull a specific lever would depend on the results of another slot machine, so on down the line.
This is not “free will” in any sense – even compatibilist notions would have a problem with it. It isn’t even any type of “willing” that anyone would want. At least in a world where causality dictates our actions we can have consistent and reliable causal results. This is what we seem to have. Maybe it’s the case that these ontic probabilistic events take place but are trumped by the causality at the macro-scale? Who knows – but be assured that you wouldn’t want quantum probabilistic events as part of your decision-making processes. And they certainly are not your free will savior (I’m talking to you libertarians).
It’s important to bring this article back to the point that this hypothetical “ontic probability” that is being assessed here isn’t really something we have to worry about. After all, it’s a logically incoherent concept. But given that we pretend it is not, we must conclude that it doesn’t help free will anyway. So please stop using the probabilism of quantum events as something helpful to the case of free will. At best such probabilistic events would be benign to our decisions and we would still lack of free will. At worst they would be detrimental to our decisions and any causally willed coherency (and we’d still lack free will).
'Trick Slattery
Latest posts by 'Trick Slattery (see all)
- Semantic Shift Day, August 31 – REMINDER! Mark your calendar! - August 1, 2020
- Debunking Dennettian Diatribe - May 2, 2018
- Compatibilism: A Parable (comic) - December 7, 2017
7 Responses to ““Realist” Quantum Probability Cannot Grant Free Will”
Sorry, the comment form is closed at this time.
Probability is defined as an epistemic measure. So when a similar ontic measure is needed in a description of QM (the similarity evidenced by proofs of their relationship), you prefer a different word be used. “The square of the norm of the wave function” is a bit too bulky, I think you would agree. Would you prefer a word like “chance”?
Note that (1) Most realist interpretations of the quantum world are indeterministic (by your definition of deterministic), and (2) generally proceed to demonstrate the “chancy” nature by mathematical proofs (based on the interpretation’s underlying theory), which are well supported by the evidence.
This is far more logically rigorous than defining “deterministic” as “all events have a cause”, and then assuming without proof that such implies that the world “could not have been otherwise” – an assertion that is easily refuted by counterexample.
“Chance” is no less problematic when assessing a range of probabilities. Regardless, this article was about allowing for ontic probability or chance and explaining why it doesn’t help with free will anyway.
No, pilot wave theory is a realist deterministic account.
The “chancy” nature of the maths is in both deterministic and indeterministic accounts, but some imply that there is a variable and others do not. That is the distinction.
Sorry, but that is how the word is used in physics. That is why both pilot wave and MWI are considered deterministic.
I’ve written an entire book explaining why such would imply that, so this idea that it is being “done without proof” is nonsense. There is a logical case for why a cause cannot both be the cause of X and not the cause of X, as that suggests a self-contradiction. There is no “counterexample” (and we are not going to get into a MWI again here).
That being said, I’ve explained time and time again that I’m agnostic over whether there is indeterminism in the universe, and if there is, I think an otherwise was possible.
> (1) Most realist interpretations of the quantum world are indeterministic (by your definition of deterministic)
> No, pilot wave theory is a realist deterministic account.
The existence of a counterexample is why I said “most” and not “all”. You should reserve the word “no” for when you disagree.
> > This is far more logically rigorous than defining “deterministic” as “all events have a cause”
> Sorry, but that is how the word is used in physics. That is why both pilot wave and MWI are considered deterministic.
In physics “deterministic” is used to mean unitary, not “all events have a cause”. You won’t find anything like “all events have a cause” in a description of pilot wave theory or MWI. In any case MWI isn’t a realist interpretation of the world (e.g. “events” do not ontically “occur” in MWI); see http://gafter.blogspot.com/2016/01/the-many-worlds-interpretation-is.html
> There is a logical case for why a cause cannot both be the cause of X and not the cause of X, as that suggests a self-contradiction.
Your reasoning assumes that a variable “is a cause” independent of which of two possible world histories we examine. But a variable is, by your definition, only a cause if it is the input to some event. It cannot properly be called a “cause” except with respect to some particular world history.
If one were to construct a counterexample one would use a different sequence of causal events in the two world histories to demonstrate “could have been otherwise”. If a variable is the input to some event in one world history (i.e. a cause), and not the input to some event in another world history (i.e. not a cause), then your “logical” reasoning doesn’t apply. Even if the variable is a cause in both world histories, it may be input to *different events* in the two world histories, in which case there is no self-contradiction.
If you’d like I can construct a simple counterexample to make this concrete.
Last I checked there were approx 7 that were indeterministic and approx 9 that were either deterministic or agnostic over determinism/indeterminism.
What you will see is the word “variable”, etc. The reason pilot wave theory is determinsitic is that it entirely variabled, which is the same thing.
I didn’t want to get into this convo again as we haven’t finished our other and I have no time to correct you. Just know that there are both realist and unrealist accounts of MWI (of the other worlds), but either way it’s a deterministic interpretation. But even if it was indeterministic, it makes no difference to the point.
Some particular world history is what the variable is for. A deterministic account says that any world that happens has a “variable” for it…a cause. If you are suggesting the event has no variable, you are injecting in indeterminism.
How would a different sequence come about if the very sequence of causal events were also caused?
Which “world history” it stems from is irrelevant. The world history is equally as causally dictated.
To assess a different history, you need to postulate either a self-contradictory variable, or an acausal event.
You are missing the logic. You can simply “assert” that there can be a different history given no non-caused events, but the very idea is illogical. All “histories” or “worlds” are dictated by variables that produce them. The only escape from this is to postulate an event that does not have a cause.
But this is all off topic from the point of the original post above.
In fact, this blog post is even allowing in the illogical notion of probability being ontic in the strongest sense, and addressing the other point, which is that there is no conscious control over such probabilistic events. I’d prefer we stay on target to this point.
I insist that if you want to address these other points we do so in our offline discussion. I like to keep these discussions that fall under a post on point to the post as much as possible. Other off topic things you can feel free to email me on and I’ll try to respond at some time within the next year (when I get time in other words). 🙂
Later.
Compulsion and free will are products of our imagination.
Free will certainly is! 🙂
Thanks for the visit Michael.
Both are. Like darkness and light; hatred and love; sickness and health; chaos and harmony; profit and loss; and other seemingly conflicted concepts of the mind, compulsion and free will constitute an inseparable couple, aka dualism. 🙂