Conway's Proof Of The Free Will Theorem
cs.auckland.ac.nz
cs.auckland.ac.nz
The Stanford Encyclopedia of Philosophy has an article on the subject: http://plato.stanford.edu/entries/compatibilism/
How does free will+determinism imply an outside influence?
I see no convincing reason that an entirely deterministic thing can't have "free will".
Though I don't remember ever having found a definition of "free will" that I've found satisfactory.
I don't think compatibilism implies a belief in anything "supernatural" though.
(quotes to indicate things potentially not being exactly the right term, or other similar indications)
This is clearly untrue. The discovery has already been made that events in the universe happen in one of two ways:
1. "deterministically", the way you think would be VERY disruptive
2. determined by chance
This isn't disruptive; people just ignore it.
When a useful professional in another field such as you or I starts wondering about these sorts of issues, he can simply pick up a philosophy book, note that a bunch of smart people have already thought this issue through, put labels on every possible position, argued through the consequences of each, and still failed to come to any consensus about it. And then we can say "Whew, glad someone's already taken care of that" and get back to our useful lives without worrying our pretty little heads about it too much.
So if you do find yourself worrying about free will, I suggest reading the vast amount of pre-existing literature on the subject and unburdening yourself of feeling like you should be making progress on it.
If the pool table were the universe, the course of the billiard balls is predetermined until the shooter shoots. No shooter, no change.
If the solar system were the universe, the planets would be deterministic until the aliens blow up Jupiter. Aliens don't exist? Then the planets would be entirely deterministic for the full course of their lifetime.
If the universe were the universe, all particles are completely deterministic, unless spooky ghosts make magic. Whether the spooky ghosts are real is a question of gullibility.
- The particles making up the universe are deterministic, unless free will is exercised.
This would amount to a concession that while free will is possible, it has never been used. I don't think that's what parent had in mind.
Even if free will exists, our mechanism for arriving at a decision to do one thing over another thing pretty much needs to be context-dependent - i.e. we make that decision based on some line of reasoning (whether correct or not).
At the same time, everything we've experienced and consider to be part of our own individual identities, the stuff that defines our free will, is incorporated as a part of that context. So many people argue that free will and determinism are still pretty much compatible.
Nevermind all the other crap we like to pretend doesn't influence our decisions like whatever crazy hormones happen to be elevated at the time.
I believe we keep telling us stories about a "free will" because we're afraid of that thought because we misinterpret it. Most people answer unreflected things like "that would be like living in a prison". Also we have learned to judge everything and everyone. How can we expect people to completely drop all kinds of judgement?
We should stop judging.
Because nobody has been able to show "free will" is more than just another belief (as in religion) and it is therefor no basis for rational discussion. And if free will does not exist, our concepts of "merit" (on the positive side) or "guilt" (on the negative side) are worthless and should be abolished.
That's why there should be no judging at all.
(Note: No judging does not mean nobody goes to prison for crime. It simply means we must redefine "punishment" as "a neutral sanction" or better: "protection from happening again".)
If somebody explains you the reason why judging does not make any sense and you understand it and apply it to your life, then it wasn't "free will". It was causality - you're doing it because of a "variable" (the explanation) that was part of your "system". Obviously, there is a huge number of other variables participating in your decision, not just one, and you could track them on a micro level (molecular) as well as on an macro level (i.e. your family, friends, wealth, etc.).
Yes, rational thinking dictates exactly this conclusion (the apparent randomness being introduced by our current understanding of quantum physics).
> And while I think that there is no free will [...] in everyday life I just keep pretending I have free will.
Well, Rome wasn't built in one day. Our whole culture was built upon the illusion of "free will" (same goes for other beliefs like magic, gods, etc). It's a good exercise to remind oneself about this when we get all worked up over something or somebody.
If the logic has a flaw, please let me know, I'm interested in being as close to the "truth" as possible.
As discussed, it would mean, for example, that we cannot judge anyone (and at the same time claim to be rational).
To give an example: The death penalty should no longer exist, because it is solely "justified" by judgement along the lines of "person X is evil and therefor doesn't deserve to live". There are no evil people, only people who do what they have to do, given the variables in "their system". That means there should be no "punishment", but emotionally neutral measures to prevent the suffering from happening again (i.e. locking the person up). It's pretty clear to me that a much more humane society will be the result of this understanding. And who wouldn't want that?
Edit: "rational" in the sense of "logical".
No, it doesn't. I mean, the rational actor model is evidently false for lots of other reasons, but its a purely mechanistic model but for the utility function (on whose nature it is completely neutral), so rationality is just as compatible with the non-existence of free will as it is with the existence of free will (in fact, rationality requires either that there be no free will or that it be confined entirely within the utility function.)
If there is no free will and we still judge, we cannot not judge!
All there needed to be was for the handful of initial variables that were set at the "beginning of our universe" to have such values that their interaction over time would lead us to rational thinking and therefor our understanding that there is no "free" will.
Simply put: If I explain to you why free will is an illusion and you stop judging, then it wasn't a "free" will. It was a cause-and-effect situation.
If there is no free will and I stop judging, then yes, obviously we can stop judging.
But if there is no free will and after your explanation I still judge, then no, we cannot.
My explanation would be only 1 variable in your system (out of an infinity of others, if you assume that you can always continue to "zoom in").
Now, if that 1 variable does anything to your decisions or not depends on all the other variables as well, i.e.: You may have gotten a very religious education which may lead you to accept beliefs put forth by other as "the truth", without questioning. Since one major point of religion is "free will", I'm not sure "my explanation" would do anything to your decision making.
On top of that, how would choice make more sense in a random universe?
To get to your question about what free will would be then: I'm not a huge fan of a pure concept of free will, though we talk about people acting more or less freely often enough that it's worth thinking about. I think then that a useful definition of "free will" might simply be a measure how much somebody's actions are able to be in accord with their desires. How an outside observer would ever gauge that as well as what actions, desires, and the two being in accord would mean are obviously murky philosophical territory, but it's pretty late.
To answer at least one obvious rejoinder, actions and desires can certainly be reduced to particles and the like, but they are phenomena that have qualities we wouldn't ascribe to particles. For instance, it makes little or no sense to say that a particle has a nice smile. In much the same way, we generally mean something different when we say a person wants to do something and a particle wants to do something.
Suppose I'm making up my mind whether to buy some item. There is some last-nanosecond non-deterministic quantum event that causes a neuron to fire, that wouldn't otherwise have fired, and I buy the item. What was 'free' about my decision if that quantum event was not caused or influenced by 'me'?
Non-determinism informally says that some things in the universe may be unpredictable. If my decisions depend on unpredictable events in the universe, how are they 'free'? It sounds like 'at the mercy of random events in the universe'.
So it's not that the world can be deterministic and you can still have 'free will', it's rather that if the world was non-deterministic, you still couldn't have that sort of 'free will'.
Seriously though -- this is extremely depressing to me, it's literally giving me terrors right now. It's reducing all that I love and value to nothingness. How do you guys deal with this?
However, as others have pointed out in parallel answers, there are 'compatibilist' views in which free will and determinism are compatible. The sorts of 'free will' that those views apply are different from the naive idea of free will and the important point to take away from that is: it may not be clear to you or me what the phrase 'free will' actually means.
I do not subscribe to compatibilist views, because they define 'free will' as something that I do not believe is worth wanting. However, that begs the question: what is a definition of 'free will' that I do believe is worth wanting? And I have found that I cannot answer that question: I cannot define it satisfactorily in a way that is amenable to philosophical analysis, while all definitions that can be analyzed are unsatisfactory.
So it boils down to this: I believe it is important to have 'free will', but I cannot define what it means to have free will. As I cannot become unhappy about not having something that I do not understand clearly enough to reason further about, my life is effectively no different from never having thought about 'free will' at all.
So that's how I deal with it. In a way that is unsatisfactory to many people, because it seems to allow for a bit of 'insert magic here' just to satisfy my emotional need for the existence of some intuitive notion of free will. To which all I can say is: yes, I believe that believing "I don't understand" and being happy is better than believing "the best answer we can come up with is depressing" and not being happy.
Some ways folks have tried to defend compatibilism (see http://plato.stanford.edu/entries/freewill/ for discussion of what follows): motivating the idea that free will is grounded on choice on the basis of one's desires, or on choice that makes sense given one's values. There are other ways, linked to the idea of it being possible that you had chosen otherwise, and on a metaphysics of modality (i.e., of what it is for something to be possible, or necessary) compatible with determinism.
I agree. The astonishing thing about quantum mechanics to me is that it describes how deterministic laws emerge from completely non-deterministic processes.
For example, in quantum electrodynamics, a photon going from A to B, chooses a random path with a well defined probability density assigned to each possible path. When you do the math, it turns out that the shortest path between A and B is the most likely one and that's why the classical "deterministic" law that light goes in straight lines is a good approximation for large distances. Yet the path which the photon chooses to take is completely random, chosen by the photon's free will, if you will.
Read "Causation as Folk Science" by John D. Norton [1]. He sets out a very simple example of a classical system that behaves indeterministically, analogous if not in fact homologous to how the radioactive decay of a single particle cannot be predicted.
The apparatus to demonstrate this consists of a dome with a particular curve (see the paper for details). A sphere placed at the apex of the dome will eventually roll off, in a random direction. But we can predict NEITHER when NOR which direction. And yet it is a fully defined classical system.
(And see [2], recently discussed here, to see how relevant and frutiful classical mechanics remains to this day.)
(Note that a better word than indeterministic might be acausal, which is the word Norton uses when describing the dome. Either way, one need not resort to QM, regardless interpretation, to demonstrate that determinism does not in fact prevail in our universe. We can all behave in ways that are not predetermined.)
[1] http://www.pitt.edu/~jdnorton/papers/003004.pdf
[2] http://arstechnica.com/science/2014/08/the-never-ending-conu...
On the contrary, classical (pre-quantum) mechanics is certainly deterministic. The first real challenge to a strict relationship between causes and effects was QM, which (as you may recall) caused Einstein to begin a long campaign against those ideas -- "God doesn't throw dice," and so forth.
> But we can predict NEITHER when NOR which direction.
Our inability to predict an outcome doesn't constitute an argument against determinism, only the limits of experimental measurements.
> analogous if not in fact homologous to how the radioactive decay of a single particle cannot be predicted.
That's simply false. A radioactive decay's timing is certainly nondeterministic, but the direction an observed, macroscopic ball takes is deterministic, even if we don't get the memo.
Think a bit harder. If Norton could demonstrate the indeterminism of classic mechanics, as opposed to publishing a philosophical paper on the topic, he would win a Nobel prize for undermining a well-established physical principle. But philosophy isn't science.
> We can all behave in ways that are not predetermined.
We can all behave in ways that we believe to be nondeterministic, but free will remains an open philosophical question.
I'm not sure how to square that statement with the paper: The paper does sets the equations of motion for an object, equations that completely define the objects motion, but that cannot predict when the object will move. This has nothing to do with the quality of measurement.
The thought experiment he describes is well-known in the popular science press: you create two particles with opposite spins (angular momenta), but such that the spins are not determined. As soon as you measure the spin of one the spin of the other becomes determined -- INSTANTLY. There is no speed-of-light limit here. If you describe the situation as two particles colluding by sharing some "information," then FIN does not apply, as far as we know! (And if there is a limit, it is greater than the speed of light.) A physicist would instead say that no actual information is transmitted, and entanglement cannot be used to transmit information faster than the speed of light.
Since the metaphor of wave function collapse as information sharing between particles leads to incorrect physics, I don't think we should read too much into the metaphor of measurements as "free choices" of a particle.
I have a very limited understanding of physics but two questions spring to mind:
1) Why is there little doubt in the axioms, especially FIN? It requires the concepts of distance and time, either of which might not be applicable to the resulting property.
2) Why call the resulting property "free will" or "free whim"? As far as I can tell the proof is for the existence of an additional property to both the experimenter and the particle, but there is no real description of it. This is somewhat unsatisfactory addressed in the last paragraph, but really, why not just call it a "randomness" or "god" instead of "whim"?
2. Because Conway likes attention.
The article says the KS "paradox" implies that either
> 1. Each measurement of a particle is not independent but rather depended on > context. In other words, the order in which you make measurements matters.
or
> 2. The particle does not decide what the value of its spin is in any direction > until the experimenter actually makes a measurement!
As I understand it, the proof shows that the order in which you take the measurements can't matter, excluding explanation (1), because of the following thought experiment.
* Take two particles, entangled and then separated by some distance.
* More quickly than information can pass between the particles, measure one particle in three directions in some order, and measure the other particle just once in one direction which you choose right at that moment.
The second particle can't be affected by the order in which you measured the first particle's spins, but if I was able to choose a direction in which to measure the second particle's spin, then the second particle was able to choose a result to match the appropriate result from the first particle's measurements.
I think I followed this argument up until the last sentence above. What I (mis)understand to be happening here is "spooky action at a distance"; it doesn't at all appear to be a free choice on the particle's part.
In essence we established via the KS paradox that our two particles couldn't have "agreed" on their spins ahead of time, because there's no consistent way to assign all of their spins. But then we measured the two particles in the proscribed way and got a result that looks like the particles did agree on their spins beforehand.
I believe that this excludes explanation (1) from above, but I don't understand how explanation (2) is consistent with this. If it were the case that the particle was deciding its spin at measurement time (explanation (2)), wouldn't the two particles have to communicate faster than c (or whatever our speed limit is) in order to ensure that they made the same decision? We explicitly ruled out this possibility via the FIN axiom and our experimental setup.
The only way I can think of to make this work is to say that the universe doesn't "choose" which result I got until I meet up with my friend who measured the other particle. But this seems to be a far stronger claim than the article makes.
What's the right way of thinking about this?
When the two particles are set up, their wavefunctions are in sync (or rather, antisync) with each other. Particle A's wavefunction looks like an equal superposition of up and down (at least, when projected onto a single axis; the wavefunction for the full particle incorporating all the possible axes is more complicated); Particle B's wavefunction is the same but 180 degrees out of phase, so that A is up whenever B is down and vice versa.
When you make a measurement of particle A, you entangle yourself with it; that is, your own wavefunction becomes in phase with its. (Again, it's still an equal superposition between having measured up and having measured down). When your friend makes their measurement of particle B, they entangle themselves with it in the same way. So when you meet up with your friend, your wavefunctions are in (anti)phase; the universe as a whole is an equal superposition of the world where you measured up and your friend measured down, and the world where you measured down and your friend measured up.
(What does being in that superposition look like, subjectively? It looks like a 50% probability of the first world and a 50% probability of the second world. Which agrees with what we measure when performing the experiment)
> When your friend makes their measurement of particle B, they entangle > themselves with it in the same way. So when you meet up with your friend, > your wavefunctions are in (anti)phase; the universe as a whole is an equal > superposition of the world where you measured up and your friend measured > down, and the world where you measured down and your friend measured up.
If we take this perspective, are we still able to rule out possibility (1)? That is, our assumption was that what my friend did couldn't affect my experiment; we used this fact to rule out the possibility that the order of my friend's measurements affected my result. But if in some sense my experiment doesn't "occur" until I meet up with my friend, then this assumption seems not to be true any longer. Which is to say, we could explain this whole thing without requiring any "free will" / "true randomness" on the part of our particles.
So I guess we've sidestepped the question the "theorem" is aimed at, because by adopting this viewpoint we're already assuming that humans don't have any kind of physical nondeterminism (or "free will", if you insist).
Personally I think the idea was stupid as stated; having a set of dice inside your head doesn't make you any more likely to have "free will" than if you didn't, and that's all that quantum nondeterminism really means. But I guess some philosophers really did claim that this was support for the notion of free will, so it's worth refuting that as directly as possible.
So I guess you're right: if anything, a many-worlds interpretation gives more support to the idea that quantum nondeterminism has something to do with free will, because it means the nondeterminism only comes in when we look at a human's subjective observations. So yes, I think we really do sidestep the claim this way.
I remember when I voiced these opinions in my college philosophy class to a room full of denialists. It's good to know I'm not alone in my thinking in a world where multi-verse and string theory are sooner accepted than the fact that free will is an illusion.
'A world where multi-verse and string theory are sooner accepted ...' indicates a world where there is agency, and thus will. We won't even go near your normative subjective ideas about the 'good'.
You can't both deny the existence of free will, and castigate those whom with you disagree. If you're right, then none of us can be wrong -- certainly no more than a plant or a rock or the moon can be wrong.
They certainly can; in fact they have no choice in that matter according to themselves.
Or the other way to look at it, A computer program changes over it's lifespan and when you look at it from that perspective it is not deterministic.
That can sound confusing so I will put a very simple example: A fireman is on front of a fire. The fire needs to be extinguish even if you think the fire is not to be blame for what it did because after all is only a fire, it didn't do it on purpose, but regardless it needs to be extinguish. The same happens with people, they are judged for what they do, for practical purposes, when they commit a crime, they are just like a fire that needs to be put out. But not with water by with judgement.
The first diagram of the proof starts with "there exists some experimenter with at least some free will". That's a problem, as it uses the argument's conclusion as one of its premises.
Using a simpler example, it'd be like saying, "To prove that aliens exist, let me show you three simple steps: 1) let's assume aliens exist, 2) ...
The second problem here is that he seems to be trying to illustrate that if things cannot be predicted that we have free will. This is a common fallacy in the free will debate. Randomness is an attack on fatalism, but offers ZERO degree of control to humans, and therefore has no place in the free will debate.
Finally, if you want to see a much better argument, in the other direction, check out my Two Lever Argument Against Free Will that uses 25 lines of Ruby.
His theorem doesn't assert free will. It asserts that if experimenters have free will, then particles have free will. So if it's wrong, then it's not for the reason you give.
This isn't a proof of particles having free will. That's an intermediary step to saying we have it as well, and therefore you can start with a step that says we do.
And, whether or not you call this property "free will" is irrelevant to the proof itself; see the final paragraph.
1. Experimenters have free will 2. They're made up of particles 3. Those particles therefore have free will 4. Therefore we have free will (that's why it's called a proof of free will)
Item #1 above assumes the conclusion.
How did you pull (4) out of that?
Either the observer's choice of measurements of the particle is completely determined by prior events, and the observer has no free will, or the observer can at his or her whim pick a way to measure the particle. If the latter, then the particle must be able to, also at whim, pick which spin to be measured at.
He never assumes that the observer is made of particles.