Benjamin Libet's argument against free will is being questioned(theatlantic.com)
> He repeated Kornhuber and Deecke’s experiment, but asked his participants to watch a clocklike apparatus so that they could remember the moment they made a decision. The results showed that while the Bereitschaftspotential started to rise about 500 milliseconds before the participants performed an action, they reported their decision to take that action only about 150 milliseconds beforehand. “The brain evidently ‘decides’ to initiate the act” before a person is even aware that decision has taken place, Libet concluded.
I don't get how people came to the original position. Why is this surprising? A simple model would be that the decision causes both the awareness and the action. Like when your program decides to move the robot arm and logs it, the log arrives before the movement, but one is not the cause of the other.
Also there's a fair chance that whatever is taking in the external clock is adding lag. So your eyes might have been in front of a clock that said a certain time, but due to processing in wetware your awareness circuit has an old value.
Also it seems like a leap to say this is connected to free will. Whatever is causing the decision, how does the timing mean anything? It's only acausal if you thought that awareness is what causes movement.
“It’s only acausal if you thought that awareness is what causes movement”
Exactly, people believed that the thoughts they are aware of when making a decision to move were actually how they decided to move.
Yes, I think the confusion of thoughts with the mind seems to be at the root of much of the controversy surrounding free will. Narrativized thought is not necessary for action although it often accompanies it. Too often we mistake the verbal part of our mind for our whole mind, it is only a part though it happens to be the loudest!
Free will is the non-religious version of believing in souls.
When you examine what people actually mean when they use the term “free will” in the vernacular, they essentially mean something which affects the mind, but which is not the mind. It’s incoherent in light of the fact that the “it” that they’re referring to ceases to exist once the brain in question ceases to function.
Our will power is like a muscle and can get tired. What if we have free will that is not actually "exercised" all that often. Say 85% or more of our actions are basically pre-ordained by decisions we have previously fully internalized and so are basically automatic, but which still alighn with our general will. Thats like an inexpensive (cached) result from the will banks. Then actual "exercise" of free will comes about when the patterns for these cache lookups fail and we must decide. But not only that, it is not exercised unless our desire and our will diverge. If I desire a second slice of pie, but my will is to not over-eat, it requires effort (will-power) to follow through with my will. That is the exercise of free will and does not actually happen as often as we might think.
This is basically a very simplified picture of free will described by Aquinas https://www.iep.utm.edu/freewi-m/#H4
I’ve always thought of free will as something that happens in the past. Your “in the moment” response to anything will be based on your choices in the past. Those you have an opportunity to decide through overt habit and routine. Do you come home from work and drink some beers or work on a project? Wake up early and go to the gym or sleep in (because of those beers last night)? These casual chains can be broken in moments of free will. Or not.
If your brain made decisions outside of your free will which you become conscious of after the fact, then that would manifest itself as a frequent conflict: we would often disagree with the action that was taken. Because we don't disagree, it must be something that is integrated with will.
Concretely, we are not surprised that our finger moved; we believe we wanted to do that and we agree with that action.
Moreover, this readiness potential phenomenon works on short time scales. The will operates on long time scales. I can plan at 11:55 that I will move my finger at 12:00, five minutes ahead. And then when the time comes, do just that. Still, the readiness potential will play out the same way: the commands to move the finger precede the conscious awareness of the finger moving.
Couldn't it be that the unconscious mind influences the conscious mind to make it seem like we agree with the action that was taken?
Not if the action was planned days in advance.
>we would often disagree with the action that was taken
It's not that uncommon
People frequently do things that they don't want to do or didn't plan to do -- most notably drug addicts and alcoholics.
Note that regret isn't the same thing as "my hand moved without any intent from me, WTF?".
>my hand moved without any intent from me, WTF?
This is how addiction actually manifests. Put an alcoholic in front of a glass of whisky and often they will grab and attempt to drink without conscious thought.
But that also happens quite frequently and people rationalize it. Do you make a conscious decision to put your hand in front of your face when someone throws something at you?
The term for that is akrasia.
I don't see how the original experiment "debunked" free will. Wouldn't the decision-making process spark neural activity?
Yeah it always seemed like it a shaky argument to me too. Even if people were unable to accurately perceive the timing of their own decisions, that doesn't seem to preclude the idea that people are still consciously making those decisions themselves....
But humans don't exist in a vacuum, your decision process was programmed into your brain by nature & nurture, and you had no control over either - the decision process for any control you think you might have had was previously programmed into you brain without your choice.
>your decision process was programmed into your brain by nature & nurture,
But that's asserting the absence of free will, which you can't do in an argument meant to prove the absence of free will. Your interpretation of a free will experiment can't involve assuming a-priori that there is no free will.
Any discussion about free will should probably start with an agreed-upon definition of what "free will" is and what might be needed to confirm that it does or doesn't exist.
I think that's pretty much the issue right there.
The thesis was that taking the action or not taking the action resulted in different EEG patterns, Bereitschaftspotential or not, and that the spike was visible before the person was consciously taking the decision. So it's not just the neural activity from the decision-making process, it's the neural activity from taking a specific decision, seen before the decision is taken by the person. As if the decision was taken by a deeper sub-system.
Isn't this an inherent problem with looking at brain activity for this sort of thing?
Suppose free will is real, and a person makes the decision and then takes the action. The brain waves marking that the decision was made HAVE to show up before the person is aware that they have made a decision, because both their awareness has to be 'signaled' by a brain wave coming from a decision. The deciding process, the decision, the awareness of the decision, and the actual brain signal to move the muscle ALL come from the brain, and will all feedback to each other. Any awareness that you have made a decision would show up in brainwaves BEFORE you are able to articulate it, since you can't articulate something that hasn't been experienced by your brain yet.
The only thing this sort of experiment could disprove is the idea that free will comes from something OUTSIDE your brain. If we believe your brain represents everything that you are (in terms of thoughts and consciousness), then anything the brain signals can't come BEFORE you have exercised free will, since the signal IS your free will.
I am very confused as to how anyone could think your brain waves could disprove free will.
You are mixing up definitions. You use "you" to mean "brain". Under that model, of course you can't disprove free will. But the model you are using is not at all useful, as you illustrate in your confusion.
The idea of free will is typically assigned to a "conscious self-model", not just a brain. The self-model generally accepted to be an emergent construct of the brain.
Thus, in the "conscious free will" model, if the brain makes a decision and hands it over to the "self-model", there is -obviously- no free will. The conscious self-model is simply an observer after the fact. Any notion of agency that it experiences is an illusion.
I don't think I follow... even if we think of the "conscious free will" as being an emergent property of the brain, it would still be made up of brain waves within the brain.
What else would free will be but an aspect of your brain? There is nothing else for it to be?
Think in terms of a layered system (subsumption architecture is useful ).
Sure the substrate is the brain and is common to all layers, but the layers are functionally different.
The self-model, "you" is a high-level circuit. The low-level circuits make all decisions and relay the results to the higher levels.
From your second link: "Will and perception do not cause the firing of neurons; they result from it. By definition, everything we are conscious of has to be preceded by neuronal activity that we are not conscious of. That’s just cause/effect. That’s physics."
I guess that is the part that I have trouble with... especially the first sentence: ""Will and perception do not cause the firing of neurons; they result from it"
They don't cause it OR result from it... they ARE it. Everything that is us (including our free will) is made up of those neurons. Our thoughts are neurons firing. Everything we think and believe and experience and decide is contained in those neurons, their state, and their connections.
I always thought the question of free will (at least since I was a philosophy undergrad) was about whether our brains (and the universe) are deterministic or not. I feel like the more we learn about quantum mechanics and physics, the more it seems like the world is NOT deterministic. The uncertainty of the universe means the neuron behavior is NOT deterministic, and that non-determinism is where free will lies.
The neat thing about layered systems is that they don't really exist. The sin of the "layering violation" is everywhere.
And if the "self-model" is "the brain" that makes the decision?
> and that the spike was visible before the person was consciously taking the decision
Or does that just mean that our ability to measure when a decision is made is flawed?
That's the point of the article. It shows that the spike is irrelevant.
Right... I just never got why the experiment was significant in the first place.
Are you assuming "consciousness" does not involve neural activity? How does that work?
For me it more lays plain the inherent contradictions of (this version of) free will than directly disproves it. What would it mean if the conscious decision to do something came before any neural activity reflecting that?
I don't see how any kind of scientific experiment could possibly support the concept of free will. If the universe is deterministic, then obviously there is no free will - since humans are part of the universe. If it is non-deterministic then all we can say about events we identify as non-deterministic is that we don't understand them.
This is not obvious at all, even with deterministic and computable universe there is a good analog of free will.
The first thing that is needed or this to work, is for the part of universe representing the human to be separable from the rest of the universe (this is not true with superdeterminism, which requires choices that experimenters make to be correlated with the quantum states of particles they are studying, but then almost no one takes superdeterminism seriously).
This separability would allow to talk about choice, as it allows to modify or swap the human in question and recompute the future in the same universe where the human may make another choice.
The second thing is the conjecture of computational irreducibility: that is for sufficiently complex systems like humans and for sufficiently long timeframes, the only way to predict future state is to evaluate the system. This conjecture seems plausible because even cellular automata in chaotic state, do not appear to have any simplified method of evaluation
If this is true, you may be able to easily predict some of the choices human will make based on his state several seconds before that, but for longer time intervals the only way is to let the human live and make the choice (even if it lives in your computer simulation).
> The first thing that is needed or this to work, is for the part of universe representing the human to be separable from the rest of the universe
What do you mean by 'separable'? Humans are a product and part of the universe.
> This separability would allow to talk about choice, as it allows to modify or swap the human in question and recompute the future in the same universe where the human may make another choice.
I'm not sure what this shows. If you swap the human for a different one then you would expect a different choice. If you can't 'recompute' the exact same universe with the exact same human, that also doesn't show anything other than your inability to recompute.
> If this is true, you may be able to easily predict some of the choices human will make based on his state several seconds before that, but for longer time intervals the only way is to let the human live and make the choice (even if it lives in your computer simulation).
The fact that we can't perfectly predict what a human will do doesn't mean there is free will. It just means we don't understand the system enough.
If universe is deterministic and computable, then it is possible to create a simulation of a part of the universe that would be complex enough to contain humans and would be simple enough to pause computation, make changes to the state, copy the state, etc. So for simplicity i will talk about this simulated universe.
Separable here roughly means that to compute further states of a human you need to follow only particles in that human and not deal with variables describing the whole universe.
You can recompute exact same universe with exact same human, but it will give you the same result. Recomputing with different human shows that different choice was possible in principle.
In the simulation we can perfectly predict what the human will do, but if computational irreducibility conjecture is true there is only one algorithm to make that prediction, which is running the simulation itself. And because running the simulation is equivalent to letting the simulated human to live that means we do not predict, but merely observe the choice.
This is not exactly what everyone thinks when talking about free will, but this is a close enough equivalent that can exist in a computable universe, because multiple choices are available, and the choice is made by the part of the universe representing the human.
> If universe is deterministic and computable, then it is possible to create a simulation of a part of the universe that would be complex enough to contain humans and would be simple enough to pause computation, make changes to the state, copy the state, etc. So for simplicity i will talk about this simulated universe.
I don't see how the 'computable' part is relevant in regards to free will. You can write a program that outputs random numbers that it reads from some source, and you can simulate it by writing another program that outputs random numbers from the same source. The two equivalent programs will generate different numbers, but that doesn't mean they had any choice over the numbers they printed.
> Recomputing with different human shows that different choice was possible in principle.
Recomputing with different human is equivalent to creating an impossible universe. It's impossible to have two different people in the exact same situation at the same point in time in the same deterministic universe. The very action of pausing or modifying the universe from without would make the universe non-deterministic.
> And because running the simulation is equivalent to letting the simulated human to live that means we do not predict, but merely observe the choice.
Who's choice? If the algorithm is making the choice then the humans simulated by such an algorithm would not have any more free will than a video game NPC.
Using random numbers affects the condition about determinism not computability. If universe is not deterministic then the choice made does not depend only on the human making choice but also on the state of generator that creates random numbers. Of course even here it is possible that the state of human is organized in such a way to change probability distribution to not depend on randomness, but that becomes equivalent to deterministic universe with additional complications.
The computability is relevant to the argument because it allows us to create simulation, and to observe a universe from outside. If it was not computable, say required real numbers with infinite precision, and the finite approximations were not able to describe complex things such as humans, then we would not be able to complete our thought experiment.
> The very action of pausing or modifying the universe from without would make the universe non-deterministic.
There are two parts, the starting state and the evolution rule. Here the evolution rule is still deterministic, and the requirement is for it to be able to continue from different starting states.
> Who's choice? If the algorithm is making the choice then the humans simulated by such an algorithm would not have any more free will than a video game NPC.
If human is a part of universe, and does not have a soul, then he is equivalent to its starting state plus the algorithm. If the computation cannot be reduced to a simpler algorithm then no matter how you compute the future state you get that human thinking, feeling and making a choice. The difference with game NPC is that the algorithm doesn't have a hardcoded set of inputs and outcomes but can accept any inputs and produce outcomes that can't be predicted by anything other than that algorithm with that starting state.
> If the computation cannot be reduced to a simpler algorithm then no matter how you compute the future state you get that human thinking, feeling and making a choice.
What's the difference between the human thinking, feeling, making a choice and a trained neural network making a 'choice'? I would not say a neural network has free will.
> The difference with game NPC is that the algorithm doesn't have a hardcoded set of inputs and outcomes but can accept any inputs and produce outcomes that can't be predicted by anything other than that algorithm with that starting state.
You can have a program that could accept any inputs (say any binary sequence) and produce output based on that.
I think that if the universe is deterministic and computable then that implies no free will, since humans are part of the universe and therefore also deterministic and computable.
The difference is most likely the organization and the complexity of a network. Neural network doesn't have free will because it is too simple and can't even pass turing test.
> I think that if the universe is deterministic and computable then that implies no free will, since humans are part of the universe and therefore also deterministic and computable.
I agree that universe being deterministic and computable means that humans are deterministic and computable.
But what is the evidence for "deterministic and computable" implying "no free will"?
I think that computational irreducibility allows the exact opposite interpretation. Humans are deterministic and computable but the process of computation is equivalent to humans living, no matter what is used to perform the computation (moving atoms in the original universe, a computer program, or even many people with pen and paper).
So even if you can compute what the human will do, you can't predict, because the act of computing is the same as human doing. This provides the "will" part of the free will.
And if you do not stop the algorithm, and change the state to get a different outcome, then it is also free.
As a side-note, this interpretation is surprisingly consistent with the original formulation of the question of free will in religious setting, where some being outside the universe knows everything about the universe, can arbitrarily manipulate the state of the universe, but can't predict what the creatures in the universe are going to do and claims that they are free to chose.
> The difference is most likely the organization and the complexity of a network. Neural network doesn't have free will because it is too simple and can't even pass turing test.
I don't see what the Turing test has to do with free will, but it has been beaten multiple times already.
> But what is the evidence for "deterministic and computable" implying "no free will"?
Deterministic and computable universe would mean the entire existence of a human would be deterministically determined by the point in space and time he was born. If you re-ran the simulation from before the person was born to their death, the universe would progress through the exact same states.
> So even if you can compute what the human will do, you can't predict, because the act of computing is the same as human doing.
That's like saying if you ran a random program without knowing it's source code you could not predict what it would do until you actually ran it. I don't see what that has to do with free will. In a simulation free will would be the ability to change your choices between runs of the exact same universe.
>>> What's the difference between the human thinking, feeling, making a choice and a trained neural network making a 'choice'? I would not say a neural network has free will.
>> The difference is most likely the organization and the complexity of a network. Neural network doesn't have free will because it is too simple and can't even pass turing test.
> I don't see what the Turing test has to do with free will, but it has been beaten multiple times already.
my point was that neural network doesn't have free will, because it is too simple and cannot be regarded as a person, Turing test is one objective way to check if a program is capable of thinking. The wikipedia page on Turing test https://en.wikipedia.org/wiki/Turing_test is not aware of any of the times when it was beaten.
> If you re-ran the simulation from before the person was born to their death, the universe would progress through the exact same states.
sure, it would be like a time machine.
> In a simulation free will would be the ability to change your choices between runs of the exact same universe.
that would not be a free will, that would be an absence of will, because if nothing changes why would person's reaction change?
Or, its deterministic, but so complex that its literally impossible to exploit the determinism to 'look ahead' in any way ... you'd need to simulate every subatomic particle, therefore needing something bigger than the universe to 'look ahead'. So perhaps the universe is like a deterministic computer that is calculating its own future. The determinism in that case just doesn't really mean anything - it can't be repeated, it can't be predicted or exploited. And so the whole problem goes away.
How does the problem go away? If you can prove your thesis then even though you can't exploit the determinism you've proven that you can't influence the future. Doesn't that mean that free will doesn't exit and is thus an extremely important result?
The future is unknowable and you're part of the mechanism that is unfolding it microsecond by microsecond. The question of whether or not you can 'influence' it doesn't make any sense.
That is, Free Will as a concept doesn't really make any sense. Does Free Will mean if exactly the same situation happened twice, the person might choose different things? But its somehow different to just being random? And when does exactly the same situation every happen twice anyway? Its an incoherent concept.
In my head, I have sortof redefined 'free will' like this:
The world is a mass of cause-and-effect chains. For a given object/being, if you were to 'trace' those cause-and-effect chains, would most of the proximate links in the chain be within the object/being, or outside of it? e.g. a rock can fall and roll around if pushed, those chains of cause-and-effect are mostly outside it. Us, as humans, choose to do things using our brains, so the chains of cause-and-effect (or the first bits of the chain at least) are within our brains. Naturally if you trace the cause-and-effect far enough you will get to some external cause (memories of previous events, learning etc). But if you look at the proximate cause-and-effect chains, they're mostly in our brains. That - for me - is roughly what I take Free Will to mean. The center-of-gravity of recent cause-and-effect chains reside within us. We have it, most animals have it to varying degrees. Rocks dont have it.
There is also the case of several simulations of a smaller universe running in our universe, with the external observer trying to look ahead.
But even if you could simulate the universe to look ahead, most likely there is only one possible algorithm of simulation, so looking ahead is still equivalent for the tested subject living and making its choice.
So even if it can be repeated, the simulation is more like a time machine than a formula.
It's possible to predict local events with a certain degree of accuracy. The better our models/knowledge and computational capacity the greater the accuracy. We can see patterns on a macro level and exploit them without looking at electrons.
Sure yep, thats like the whole of science. But we can't predict things at the level that people worrying about Free Will worry about. i.e. what people are going to do next. Or what they will be doing in 15 years time. Or going further, the nightmre of determinism is the idea that someones whole life is determined before they are born and so on. That sort of thing is forever beyond the reach of all computation.
Would love for someone to describe effectively what free will means. Because to me the concept itself doesn't make much sense to me and never has.
I don't have free will over my breathing, in one definition (since it can be consider "involuntary"). In another definition I could say I have free will over my breathing because I could hold my breath.
What is an example of free will? And what is hypothetical experiment that would actually prove or disprove it?
For me, free will is the feeling and belief that if I want my body to do something I have a pretty good chance of making it do that. Additionally, I can decide to train some reflexive behavior and tailor it to be more of what I want my automatic responses to be. It's a feeling of integration between my desires and my actions that doesn't feel like it's driven from outside my body. For example, if I get a muscle twitch or spasm or a limb falls asleep and I can't move my digits then my sense of free will is lessened. When I walk, talk, etc. then the feeling is reinforced.
>integration between my desires and my actions
how did you decide to have these desires? if it's a good feeling, then you didn't decide that such a desire will give you this feeling; if it's based on a computed most-advantageous outcome, then you didn't decide that either. If it's a choice between the two, then who decides and how (infinite regression)?
the whole concept makes zero sense. when did i decide to enjoy the things that i like? when did i decide how my parents should raise me, or what personality forming experiences i should have as a child? when did i decide to have adhd, which essentially makes me a slave to my impulses and desires (that i again never actively chose)? either our decisions and actions are based on a timeline of prior experiences (plus genetic preconditions), starting with birth, over which we have zero control, or they're totally random, which they are obviously not, otherwise our whole existence would be total chaotic randomness. on the other hand you have people claiming that some higher being instilled some moral code in all humans, and that it's up to us to make the best out of it. in that case, again, those moral standards were not of our choosing.
Let's say the question is not settled. There are experiments showing how one can predict a choice 7 seconds before.
What's the "reverse averaging" that the article talks about?
Would recommend everyone interested in the topic of Free will to listen to this episode of BBCs In our time: https://www.bbc.co.uk/programmes/b00z5y9z
Interesting science, but it's not possible even principle that such experiments could determine the presence or absence of free will. It's kind of like a child trying to figure out how Big Bird walks by studying the guts of a TV.
How can you discuss free will and completely ignore the most basic philosophy on the topic, the distinction between compatibilist and incompatibilist definitions of it? Libet’s argument is an argument against incompatibilist free will (aka metaphysical libertarianism), not compatibilist free will. Whether or not it succeeds at that, it doesn’t disprove compatibilist free will in any way, it doesn’t even try to.
I think basically you can disregard any study or article that purports to say that "science" has found why humans behave in a certain manner or that attempts to answer philosophical or social questions using fMRI or EEG.
Sure, if you are a dualist.
There is no free will, but, there is free will. Easy.
To say an argument has been "debunked" implies that the argument holds no credibility, or the rhetorical equivalent of "I'm right, you're wrong." It is an attempt to shut down a discussion and provide fodder for ad-hominem attacks against those who dare to disagree.
In other words, The Atlantic should be ashamed to run a headline like this because it is antithetical to rational discussion.
Ok, but what's a better word? Refuted? The article makes clear that Schurger's counterargument has been generally accepted.
Edit: given the link in https://news.ycombinator.com/item?id=21486117 I suppose we can say "questioned".
I don't think it's even refuted. It's just redefining what 'decision' is and using that to somehow make the case for free will.
Previously they were saying that the start of the neural activity was when a decision was made, and now they are saying that the decision is only made when a particular threshold is reached, but either way the decision is a result of neural activity that began before the person was consciously aware of it. They're just redefining terms to reach the result they wanted.
The assumption that conscious awareness is necessary for an exertion of free will is also a mistake. The original conclusion was chock full of assumptions. No one debated the specifics of the observed data, what is debatable is the meaning of that data.
If the whole argument was based on an experimental result, and that experiment has now been found to be fundamentally flawed and the results of the experiment invalidated, then it seems entirely fine and rational to say that the argument has been debunked.
or, the argument is against the evidence of one experiment. similar protocols using other techniques have provided evidence against the idea that behavioral decisions can be unpredictable.
Seems to be used all the time for things that aren't a scam, a hoax, a lie or something like that.
This is one of the example sentences Mirriam-Webster gives for the word debunk:
> The results of the study debunk his theory.
You're not wrong. Especially since, http://blogs.discovermagazine.com/neuroskeptic/2019/10/31/th... "The Ghost of Libet Returns"
Debating on headline that are often chosen or changed by editors to be controversial or more dramatic is waste of time. Magazines do it routinely.
HN sometimes changes headlines to be more correct. Propose one.
It's not just in the headline. It's in the article's body as well:
"The topic is immensely complicated, and Schurger's valiant debunking underscores the need for more precise and better-informed questions."
Ah, the hallmark of 20th century pseudo-intellectualism: operationalize an ill-defined concept (e.g. "free will," "rationality," "empathy"), produce a dubiously reproducible experiment, maybe write a controversial paperback making ridiculously hyperbolic claims, let the press go apeshit, $$$.
Other flavors include: Pluck a plausible, edgy explanation out of a vast hypothesis space (e.g. evolutionary psychology), over-reductively apply a catchy theorem to a vastly complicated domain (looking at you, game theory). Take a thin, ecologically invalid model and claim "that's how the brain works!" (both neural networks and sybolic reasoning systems).
I feel like in this century, we've realized that all of this was maybe useful as a reference point to formulate hypotheses, but become less stupid about the conclusions we're willing to draw (as a population).
The wonderful reality is that we don't really have strong opinions about free will, because we're not sure we really know what that could mean or why precisely it seemed so important a century ago.
You seem to be saying people were idiots for relying on the results of one experiment -- how could they be so stupid? Yet here you are, completely buying into the results of one recent paper as it agrees with your own model of the world (apparently).
As for being edgy, you are taking a condescending position using broad and vague claims that are impossible to refute ("looking at you game theory").
I agree that by itself "free will" is meaningless to talk about unless the term is defined. I'm sure most if not all authors on the subject do define what they mean by free will, eg, Dennett and Harris, but I'm sure there are many others who do.
>> (both neural networks and sybolic reasoning systems).
Woa, woa. Symbolic reasoning _has_ been claimed to model the way the brain works (the original Pitts and McCulloch neuron was a propositional logic circuit that purported to model the way actual neurons work) but that sort of thing is much more common in connectionism. In fact, it's basically the whole story of connectionism ("let's copy the brain").
In any case first order logic was originally proposed as the foundation of maths, and nothing to do with how the human brain works.
> why precisely it seemed so important a century ago.
Free will is a proxy argument in the debate about physical determinism, which is a component when talking about metaphysical and spiritual reality, which comes up in discussions about the existence of God - whom the modern zeitgeist doesn't believe and/or wishes to disprove.
A good question to ask does the answer to any of these nebulous ill defined questions have any non socio-politcial consequences? If the answer is no, be very very dubious.
The concept of free will has tremendous implications for oursocio-policial world, such as in criminal justice or even taxation.
Not really. Presumably a criminal justice system ought to be designed to be effective at rehabilitating and deterring crime. That's a strictly empirical enterprise that needn't concern itself with abstract notions of free will.
The law could of course codify its own definition of free will, which it typically does, but again this need not be affected by outside notions.
Yes but what are the non socio-politcial consequences? There aren't any. Does it matter if a pilot flying a plane has free will or not? No not really.
That's a tell that using any particular answer to this question for policy is a bad idea.
And if the answer is yes, be very very suspicious!