The ideas of free will, causality, and determinism, often factor into discussions about religion, morality, society, consciousness, or life in general. The first and last of these ideas seem at odds; if the world is strictly determined, there can be no free will.
But we are confronted with the appearance of free will — choices we make appear to affect the future. Even choosing not to make choices seems to affect our future. If reality is just a ride on fixed rails, then all that choosing must be a trick our brains play.
These questions are central to lives, but answers have remained elusive, in part from differing views of what the key ideas even mean.
Sometimes a precise definition of terminology helps make things more clear. Sometimes it doesn’t, but at least it’s a good place to start.
(“Doe, a deer,…”)
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Free will is generally defined as the ability to make a choice that seems arbitrary in terms of past information.
It’s the idea that, if we rewind time to a given choice, a different choice was possible at that point, even though the past would be the same for both choices.
When I look in my pantry to decide which kind of soup to have, and I pick minestrone, could I have picked clam chowder instead? Or does the physics of reality insist that, at that moment, I must choose minestrone?
[It gets weird: If free will truly doesn’t exist, I was always going to write this post and ask these questions. (And you were always going to read it.) Every opinion we have on this, any actions we take based on those opinions, are predetermined.]
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Determinism generally means we can accurately predict future states of the system given its current state.
Alternately, it means the current state allows us to deduce past states — which includes an implication there is only one possible past. (The first view implies there is only one possible future.)
Essentially determinism sees a system as a clockwork machine that can be wound forward or backward to any point with the same result. Wind to any given point and we always get the same system state.
That is, assuming the determined system is bi-directional — that need not be the case. A system can be determined in only one direction.
For instance, the current state might allow predicting future states, but past ones might be unknowable due to information loss. If the hands on an electric clock say it’s twenty after four, when was the clock plugged in? How many times have the hands gone around?
Or perhaps the current state implies a specific past, but there is some randomness to future states. This, in fact, seems to be how things are. Or at least how they appear.
I think we tend to think of determinism as applying to future states. But a fully reductive machine-like view of reality implies bi-directional determinism.
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Causality seems a questionable concept to some philosophers. For me it’s nothing more, or less, than the laws of physics.
These laws provide an explanation for why A “causes” B.
Essentially it’s a case of local interactions. Light cones are significant. That the speed of causality, the speed of light, and the max allowed speed, are all the same thing is a central axiom of reality.
That said, there is a philosophical point as to whether physical laws are just observations of patterns with no necessary underlying causal connection or whether those observations do reflect a lawful causal universe.
Given the consistency of our observations, the latter seems a reasonable bet. We appear to exist in a physical reality governed by physical laws.
Those laws say why A causes B — because gravity, or mass, or magnetism, or charge, or frequency, or whatever.
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The basic laws of physics are seen as bidirectional in time, which implies causality is bidirectional.
For some this suggests an issue with causality. If A causes B, but B also causes A, isn’t that a contradiction?
It isn’t, because in any given situation, one always causes the other. That a causal link is potentially bidirectional doesn’t mean both happen at the same time.
So causality, as a set of physical laws, is bidirectional — the extra ingredient is time, which (I believe) is fundamental, and which runs in only one direction. (In my view, causality and entropy are, demonstrations of time’s arrow; they do not create it.)
The laws of physics, plus time, result in (one-way) causality as we perceive it.
[I stress this is just my view: Time is fundamental. We live in an evolving universe. The past “happened” and is fixed; the future is undetermined; “now” divides them. I like the metaphor of the loom. We weave a fixed past from threads available to us.]
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Determinism is about how predictable causality is.
If the result of a causal interaction has a single outcome which can be predicted, then that interaction is determined. If all interactions are determined, then the future is determined.
In reverse, if all outcomes have only one possible history, then the past is determined.
I don’t believe either of those are strictly true.
Note that systems can be determined (or not) at different levels. A key question involves determinism at different scales.
Also note there are things — chaos, for instance — that effectively interfere with our ability to predict a determined system, except in the short term. Another example is how the way things degrade over time interferes with our ability to determine the past.
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At reality’s lowest level, the Schrödinger equation, which describes the evolution of a quantum system, is fully determined.
My understanding is it is bidirectional — it describes the system’s dynamics forwards or backwards. The implication is there is only one possible past given the present, which is why quantum information is never lost.
The wrinkle in all this involves actually “looking at” that evolving system (making a measurement). When we do that, the Schrödinger wave-function “collapses” to some random value among possible values the system could have.
Which is all she wrote for determinism at the quantum level.
If anything, the quantum world is noted for its randomness!
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Physical law at higher levels are also determined, and there is no random wave-function collapse.
That would seem to make (for example) chemistry deterministic. On the large scale, I suspect it is, but I’m dubious about the fine scale.
To be strictly determined on the fine scale, a specific configuration of trillions of atoms must evolve in exactly the same way every time. There can never be a single atom out of step or out of place.
One problem here is there’s no way to accomplish this experimentally (or even accidentally). Due to Heisenberg, it is impossible to give one atom, let alone a huge group of them, a specific position and momentum.
So while chemistry has determined outcomes, you get so many ounces if you do this, that, and the other thing, I’m not sure the outcome is determined down to the atom.
[For one thing, new research has shown important quantum interactions between molecules of water. Those interactions affect its viscosity.]
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At higher and higher levels, we’re dealing with larger and larger quantities, which seems to make strict determinism weaker and weaker.
So I’m not entirely sure I buy strict determinism at any scale. I’ve been reading about others who don’t buy it either. (More than one.)
Reality is definitely causal, but I think it is fuzzy enough that it’s not determined. Not in the strict physics sense.
I think the past is determined in a causal sense, but not in a one-history sense.
Given a current configuration, and physical laws, it’s possible to see how a preceding state evolved into the following state. But in some cases, multiple possible previous states might all lead to the same following state.
A common example is a glass of water. It might have been a glass of ice cubes, or it might have been a glass of hot water. Both pasts lead to the current state.
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There are social and personal forms of determinism, but I think we are not so much like Pavlov’s dogs that we can’t overcome those if we try.
But I don’t think I live in a strictly determined world, a clock-like machine world that could potentially be wound forwards or backwards.
I think complex systems may not be determined, and since the brain is a very complex system, it may not be determined. Which puts free will back on the table where it at least feels like it belongs.
I can’t remember who I heard say it, but someone recently expressed something I’ve been saying for a while: chaotic systems in the brain may result in free will.
It would certainly explain why, despite millions of years of evolution, our brains seem to make decisions in an undetermined world.
Stay causally determined, my friends!
∇
Logos con carne 
December 17th, 2019 at 5:57 pm
I tend to think the brain is at least a mostly deterministic system, mainly because a significantly indeterministic system doesn’t seem like it would be adaptive. But as a compatibilist, I don’t see free will linked to determinism anyway.
Did you see Sabine Hossenfelder’s post on superdeterminism? If so, I’m curious what you think about it.
December 17th, 2019 at 7:27 pm
“I tend to think the brain is at least a mostly deterministic system, mainly because a significantly indeterministic system doesn’t seem like it would be adaptive.”
Absolutely. Mostly. 🙂
From an evolutionary point of view, a mechanism capable of choosing seems like it would be very adaptive, since choosing seems tied with self-learning. (“What if I try this, instead…”) A fully deterministic organism would need a randomizing element to ever escape its patterns.
re superdeterminism, I can’t say much about it, because every time I try to read up on it, it makes my head hurt. Her current post doesn’t get into it much, but there was one earlier that did. From her description, it sounds like the opposite of what I believe and argue here.
December 17th, 2019 at 8:31 pm
I’m not sure about the need for a randomizing element. That would only be true if it received the exact same stimulus, which for any open environment, seems unlikely.
Superdeterminism seems like conspiracy determinism. It’s a level of determinism even most hard core determinists aren’t comfortable with. But I’d like to understand why Hossenfelder sees it as plausible. I hope she does a layperson explanation sometime soon.
December 17th, 2019 at 9:10 pm
True, the environment offers changing stimulus in a given range (temps vary, for instance). Even so, novel strategies require something extra. Genetic programming (or just genetics) works by introducing random elements to kick the system into a novel state it wouldn’t otherwise take.
Did you see Hossenfelder’s post from back in July? She does explain it a bit in that one, but I can’t say it helped me much.
December 18th, 2019 at 8:04 am
Thanks for the Hossenfelder link. I had read it but just re-read it. She seems to think the major objection is free will. But that’s not my issue. My issue is that I need to see some plausible account of these hidden variables that extend from the beginning of the universe.
December 18th, 2019 at 8:40 am
Very much likewise. Going back to evolution, why would nature evolve this massive resource hog if all it does is go along for the ride and think, “Oh, pretty flowers!” Why would we evolve a tool capable of understanding that it is (supposedly) basically useless? I need to see much better proof.
This tendency to insist the universe works like a clock-work machine… it seems downright Dark Ages to me. At the very least, really boring. 😉
December 18th, 2019 at 9:21 am
I’m actually open to the clockwork universe, although given quantum physics, it seems like it would be much stranger than anything Enlightenment theorists were thinking.
But to me that’s irrelevant for free will, which I see emerging at a higher layer. My choices may be predetermined, but it does me absolutely no good. I still have to assess the possibilities with imperfect information and make the best decisions I can.
In my mind, adding random steps doesn’t add any meaningful freedom. If anything, I see that as more unsettling than strict determinism, since at least with determinism, education and training are meaningful in trying to be the person I want to be. If a random fluctuations can derail that, it’s not a notion I find comforting. (Although I’m also open to it being reality.)
December 18th, 2019 at 10:24 am
Isn’t there a contradiction between your choices being predetermined and the idea that you’re, in any sense, actually making them? You just think you are, right? No matter what you decide, it isn’t you at all, but the universe. Any education or training you “decide” to get was predetermined 13.8 billion years ago.
December 18th, 2019 at 12:27 pm
I don’t see it as a contradiction, but a lot depends on how you define “choice”. Do you see a computer running through an if-then-else sequence as making a choice? I do. I suspect you’d say that was not a real choice. But other than complexity, I can’t see a real difference.
Consider whether it would make a difference if one of the factors in the if-then-else sequence were the result of a quantum random number generator. You might say that consciousness is missing, but then it might come down to whether you think nonconscious decisions happen in people. I think they do, and the law tends to hold people accountable for their decisions, conscious or not (absent clearly mitigating circumstance).
Another way of looking at it is whether something is a choice or a predetermined sequence is a matter of perspective. Relative to me, my action selection is a choice. Relative to the overall universe, it’s just a sequence playing out according to the laws of physics.
That being said, whether such choices are real choices or pseudochoices is a matter of philosophy. But if no “real” choices are possible, it strikes me a cumbersome to refer to everything we normally take to be choices as pseudochoices.
December 18th, 2019 at 1:35 pm
“Do you see a computer running through an if-then-else sequence as making a choice?”
Sure, but it’s not a free choice. Wind reality back, or posit an alternate reality, and in either case at that point the computer always makes the same choice. As I define in the article, that’s not what I mean by free will.
It’s not a matter of complexity, but of it being possible, given the same inputs, to make a different choice.
But I think if-then-else is the wrong way to think about it. It’s more like lots and lots of opinions or votes to sort through. The behavior of neural nets is a better metaphor, I think, than an if-else-then statement. I see this as not being at the level of neurons or gates, but at a much higher collective level.
“Relative to the overall universe, it’s just a sequence playing out according to the laws of physics.”
My suspicion is that the larger the system, the less determined it is. (Which why ideas about how everything is set since the Big Bang don’t make sense to me.) Smaller systems have few enough variables to be deterministic, but once we’re talking many trillions and more, even the smallest input differences make the future of that system very random.
One thing I tried to do in the post was separate causality from determinism. I think reality is causal, but not determined.
The reason free will feels like it exists, and the reason we treat people as morally responsible for their decisions, is because reality is complex enough to not be determined. I think brains, on their own, are complex enough systems to escape it.
Maybe that’s too simple to be true, but sometimes I think maybe people overthink this, too.
December 18th, 2019 at 2:46 pm
I did catch the distinction you made between causality and determinism. It’s one a lot of people have made to me over the years when discussing whether quantum randomness is causally fixed.
The question is, is a truly random event fully causal? To me, it seems like something is missing. What causes the particle, when measured, to be here rather than there? Or to be spin up or spin down? You can tell me that the random event is fully causally fixed, but that feels like fiat to me.
It seems like I’m a compatibilist with free will but not with causality.
December 18th, 2019 at 3:47 pm
“You can tell me that the random event is fully causally fixed, but that feels like fiat to me.”
I suppose it depends on whether you believe ‘God plays dice with reality’ or not. It may also depend on whether there is a difference between “fully causally fixed” and merely causal.
Ever since I learned about Heisenberg, Turing Halting, Gödel Incompleteness, and wave-function collapse, my view has increasingly turned from the idea of a fixed, or even fully knowable, reality. The universe seems fuzzy at the very edges of resolution, and I believe that fuzziness makes things just indeterminate enough.
In a spectrum from fully determined to utterly random, I think reality is a lot closer to the former, but the fuzz gives it just enough unknowable input that the chaotic dynamics of nonlinear systems make outcomes unpredictable.
(As I showed in my recent Mandelbrot post, differences of just 7.1239e-23 result in extremely diverse results.)
All that said, it does absolutely fascinate me: In a two-slit experiment, a single photon appears to land in a random location. Why that spot? Is there something that ultimately determines that, or is it possible it’s literally a crapshoot?
The other one that gets me is radioactive decay. How do individual atoms know when to decay? That appears random, too (hence the cat in the box).
Those are wave-function deals. Heisenberg is a whole other source of fuzz. And the Turing-Cantor-Gödel findings, all based on diagonalization, reveal that even math — even machine-like math! — is fuzzy and not fully knowable.
All-in-all, it has me thinking Einstein was wrong about God and dice. [shrug]
“It seems like I’m a compatibilist with free will but not with causality.”
I’ve realized I’m neither a compatibilist nor an incompatibilist, since both those positions assume a deterministic reality.
I’m going to need to see some pretty good proof that we’re deterministic given all the apparent evidence arguing the opposite. Granted, it is apparent, but, at the least, I’d want that appearance explained.
December 28th, 2019 at 5:34 pm
(1) The world is strictly determined and (2) free will refers to one of the causal mechanisms that do the actual determining.
The notion that free will is the opposite of determinism is a longstanding philosophical blunder. The opposite of determinism is indeterminism.
All uses of the terms “free” and “freedom” presume a deterministic universe. Without reliable cause and effect, we could never reliably cause any effect, and would have no freedom to do anything at all.
December 28th, 2019 at 7:57 pm
“(1) The world is strictly determined…”
We have different views on this. The point I’m working for in the post is that I’m not sure the universe is strictly determined.
And let me be clear what I mean by that: In a strictly (causally) determined world, all choice is inevitable, and free will is an illusion.
As I define in the post, “free will” requires that, in some identical alternate universe, it’s possible to make an alternate choice. If both universes are strictly determined, that’s not possible.
“The notion that free will is the opposite of determinism is a longstanding philosophical blunder.”
I’ve never encountered that notion. What I have encountered is the notion that determinism excludes free will. Or that free will excludes determinism. Either way, but exclusion is not the same thing as opposition.
As you say, the opposite of determinism is indeterminism, which means the future is not determined — not predictable. In such a reality, free will is possible.
“Without reliable cause and effect, we could never reliably cause any effect,”
Absolutely. That’s why causality and determinism aren’t the same thing.
We (appear to) live in a causal world. I’m not sure we live in a (strictly) determined one.
December 28th, 2019 at 8:42 pm
I believe the correct solution is to view causal determinism as something that does not control us, but which simply includes us.
The fact that there will be one single inevitable future is not a problem when we realize that, within the domain of human influence, it will be causally determined by our own choices, to suit our own purpose, and to serve our own interests.
Choosing is a deterministic event. The choice is causally determined by our own purpose and our own reasons. Thus the choice is, at least in theory, 100% predictable.
However, the choice is never predictable at the beginning of the choosing operation. It is still unknown to us. And it will not be known to us until we ourselves have made that choice.
So, we have the fact of an inevitable future plus the fact of an unknown future. These facts don’t contradict each other.
The language of “possibilities” and “abilities” and “choices” always reference an unknown future. And the concepts derive their meaning from the choosing operation.
At the beginning of any choice, two facts are always true by logical necessity: (1) we have more than one real possibility to choose from, and, (2) we have the ability to choose either one (the ability to choose otherwise).
And this causal mechanism, performed by us, is part of the overall scheme of causation. We ARE part of causal determinism. And when we are doing our part, it is us in the driver seat.
December 28th, 2019 at 9:16 pm
We’ve had this discussion before, and all I can say is we see this quite differently.
You’re essentially a compatibilist in seeing determinism including us but also in thinking we’re influencing choices. The key point here is whether:
Or not.
If you agree there is only one possible future, in my view that is not free will, because — as I define it — free will requires multiple possible futures.
That’s only possible if reality isn’t strictly determined. I’m arguing it may not be.
I think we only really see this happening when we make choices among relatively balanced options that don’t have high impact — picking which soup to eat, for instance, or what color tee-shirt. I think there’s an element of randomness in the moment.
We pick among predictive models, and I think what happens is that one rises above the others. That’s how we pick something. Our minds are extremely noisy, which creates a random influence.
The question, again, is, in an identical parallel universe, could I pick a different soup? (Or, if you could rewind this universe to the choice point, could I choose differently?)
December 28th, 2019 at 10:44 pm
There “will be” a single future.
There “can be” many “possible” futures.
To me, those two statements are both true. Each has a different context, and each statement is true within its own context.
Notions of what “can” happen and what we “can” do, always reference an unknown future.
Notions of what “will” happen and what we “will” do, always reference a known future.
The statement “free will requires multiple possible futures” is true. And, there are always multiple “possible” futures while the future is not yet decided (that is, we have not yet reach the end of our choosing operation, which is the mechanism that “decides” things).
WS: “I think there’s an element of randomness in the moment.”
“Random” is an issue of predictability. We use statistical methods and probabilities to predict random events. In other words, our context in matters of “randomness” is an “unknown (unpredictable) future”.
But I think every “random” event is also deterministic, in that some cause(s) will be found that tip the scales one way or the other. Flipping a coin, for example, involves air resistance, the speed of the rotations, the control of the thumb and fingers, etc., which make prediction difficult. So we call the result “random”.
WS: “Our minds are extremely noisy, which creates a random influence.”
Right. But if we could examine the event in sufficient detail, we could track the noise, perhaps isolate it, and quantify its impact upon the reasoning process. That gives us “theoretical” predictability even if prediction is practically impossible.
WS: “The question, again, is, in an identical parallel universe, could I pick a different soup?”
My point is that is explicitly NOT the question. What you “could” do is a wholly different matter from what you “will” do. At the beginning of the choosing operation, where you choice is still unknown to you, your view is of two real possibilities to choose from, and that you have the ability to choose either soup.
It is only at the end of the operation, after you personally have decided what you want, that you have knowledge of what you “will” do.
At the beginning, you have two soups, A and B. Each is a “real possibility” and you have the “ability” to choose either one.
The fact that you “will” choose soup A does not change the fact that you “could have” selected either soup A or soup B.
The two facts are each true within their own time and context, at the beginning of the operation where the future is unknown, or at the end, where the future has been decided.
(Note: The choice will have been causally necessary and inevitable, through a network of reliable causes and their effects, from any prior point in history. However, it will be “decided” only by you, at the time you make your choice).
December 28th, 2019 at 11:12 pm
“There ‘will be’ a single future.”
I foresee getting hung up on this point. I’m not clear on your verbiage. Is that future inevitable?
Faced with choosing soup A or B, can I choose A, rewind the universe and choose B given the same history?
“But I think every ‘random’ event is also deterministic,”
Including wave-function collapse?
“It is only at the end of the operation, after you personally have decided what you want, that you have knowledge of what you ‘will’ do.”
This is what isn’t coherent to me. Under strict determinism, there is no personal choosing. Of any kind. Ever. I’m just along for the ride. Choosing is an illusion. I only think I have preferences that steer me. In reality, as you say…
“…if we could examine the event in sufficient detail, we could track the noise, perhaps isolate it, and quantify its impact upon the reasoning process.”
Under strict determinism that would be true. Any “choice” I “make” would be fully accounted for by quantum mechanics. Every “preference” I have is the result of some past history of particles.
December 29th, 2019 at 12:07 am
WS: “Is that future inevitable?”
Yes. But that inevitability incorporates us and our choices. Like all objects and forces in the physical universe, we cause stuff to happen. Deterministic inevitability must incorporate all causal mechanisms: physical, biological, and rational. Any version of determinism that fails to include all causal mechanism is incomplete, and thus false. And we happen to be objects that include all three mechanisms.
So, the notion of “inevitability” as being something outside of our control is not quite correct with universal deterministic causal inevitability. Our deliberate actions are part of the overall collection of causal mechanisms that bring about the single inevitable future.
WS: “Faced with choosing soup A or B, can I choose A, rewind the universe and choose B given the same history?”
This will blow your mind: (1) Yes, you “can”. (2) But no, you “will” not.
The use of the words “can” and “ability”, just like “possibility”, refer to a future that is as yet unknown and “undecided” until you make your choice.
Rewind to the beginning of the choosing operation, and you will once again have the “ability” to choose soup A or soup B.
But your choice “will” always be the same.
And it will always be the case that it is you that is making the choice.
WS: “Including wave-function collapse?”
I presume that all events are reliably caused, even if the cause remains forever unknown.
WS: “This is what isn’t coherent to me. Under strict determinism, there is no personal choosing. Of any kind. Ever.”
Quite the contrary. Under strict causal determinism, choosing is an inevitable event that will in fact happen. The operation takes place in the physical infrastructure of our neurology. It happens in physical reality, and you can watch the brain activity on a functional MRI.
So, anyone claiming that choosing doesn’t happen would be contradicting neuroscience.
WS: “Any “choice” I “make” would be fully accounted for by quantum mechanics.”
Doesn’t matter how you account for it, it happens. Of course no one would attempt to account for it with quantum mechanics, or even with just the laws of physics. Choosing is a rational causal mechanism, where the outcome is deterministically caused by our purpose, our reasoning, and our interests.
Physics can explain why a cup of water flows downhill. But it has no clue as to why a similar cup of water, heated, and mixed with a little coffee, hops into a car and goes grocery shopping.
December 29th, 2019 at 12:35 am
We’re at an impasse because we have fundamentally different views…
A key point here is that we agree strict determinism means an inevitable single future.
“Deterministic inevitability must incorporate all causal mechanisms: physical, biological, and rational.”
This is where my view differs. To me, under strict determinism, those are all the same thing. Everything above basic physics is emergent.
“Of course no one would attempt to account for it with quantum mechanics, or even with just the laws of physics.”
It would be computationally challenging, but the point is, under strict determinism, the basic laws of physics do account for it.
“Choosing is a rational causal mechanism, where the outcome is deterministically caused by our purpose, our reasoning, and our interests.”
Under strict determinism, with a single determined future, choosing is an illusion. Our purpose, our reasoning, our interests, our free will, are all illusions. Epiphenomenon. They are emergent and fully explained by a history of particle interactions.
I know you don’t agree, but that’s what strict determinism implies: a clockwork universe. The MRI activity is just that mechanism in action. It means nothing more than an xray of a clock.
“Physics can explain why a cup of water flows downhill. But it has no clue as to why a similar cup of water, heated, and mixed with a little coffee, hops into a car and goes grocery shopping.”
That depends on your theory of consciousness. Under many physicalist theories, physics absolutely explains why you go grocery shopping with a cup of coffee.
If you don’t believe even wave-function collapse is random, then you really do believe in a clockwork universe. The problem is that doesn’t seem to fit the evidence.
June 5th, 2021 at 3:11 pm
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