[danbruc]

The existence of a flawless predictor means that you do not have a choice after the predictor made its prediction, the decision must already be baked into the state of the universe accessible to the predictor. It also precludes that any true randomness is affecting the choice as that could not be predicted ahead of time.

I do not think that allowing some prediction error fundamentally changes this, it only means that sometimes the choice may depend on unpredictable true randomness or sometimes the predictor does not measured the relevant state of the universe exactly enough or the prediction algorithm is not flawless. But if the predictor still arrives at the correct prediction most of the time, then most of the time you do not have a choice and most of the time the choice does not depend on true randomness.

Which also renders the entire paradox somewhat moot because there is no choice for you to be made. The existence of a good predictor and the ability to make a choice after the prediction are incompatible. Up to wild time travel scenarios and thinks like that.

[ordu]

> Which also renders the entire paradox somewhat moot because there is no choice for you to be made.

Not quite. You did choose your decision making methods at some point in your life, and you could change them multiple times till you came to the setup of Newcomb's paradox. If we look at your past life as a variable in the problem, then changing this variable changes the outcome, it changes the prediction made by the predictor.

> The existence of a flawless predictor means that you do not have a choice after the predictor made its prediction

I believe, that if your definition of a choice stop working if we assume a deterministic Universe, then you need a better definition of a choice. In a deterministic Universe becomes glaringly obvious that all the framework of free will and choice is just an abstraction, that abstract away things that are not really needed to make a decision.

Moreover I think I can hint how to deal with it: relativity. Different observers cannot agree if an observed agent has free will or not. Accept it fundamentally, like relativity accepts that the universal time doesn't exist, and all the logical paradoxes will go away.

[chriswarbo]

> I believe, that if your definition of a choice stop working if we assume a deterministic Universe, then you need a better definition of a choice. In a deterministic Universe becomes glaringly obvious that all the framework of free will and choice is just an abstraction, that abstract away things that are not really needed to make a decision.

Indeed, I think of concepts like "agency", "choice", "free will", etc. as aspects of a particular sort of scientific model. That sort of model can make good predictions about people, organisations, etc. which would be intractable to many other approaches. It can also be useful in situations that we have more sophisticated models for, e.g. treating a physical system as "wanting" to minimise its energy can give a reasonable prediction of its behaviour very quickly.

That sort of model has also been applied to systems where its predictive powers aren't very good; e.g. modelling weather, agriculture, etc. as being determined by some "will of the gods", and attempting to infer the desires of those gods based on their observed "choices".

It baffles me that some people might think a model of this sort might have any relevance at a fundamental level.

[vidarh]

This is a compatibilist view. However, we can tell that most people don't adhere to a compatibilist view of free will because it tends to make people very upset if you suggest they have no "genuine" free will or agency, and the moral implications behind the assumption of genuine agency are e.g. baked into everything from our welfare systems to our justice systems, that assumes people have an actual choice in what they do.

For that reason I strongly disagree with the compatibilist view - language is defined by use, and most people act in ways that clearly signal a non-compatibilist view of free will.

[ordu]

I personally don't see any problems with this. For example, in most cases we can agree if someone had free will or no when they committed a crime. Even if I prefer compatibilist view and you are not, we'll agree in the most cases. In the cases when we may not agree the reasons of disagreement will not stem from this fundamental disagreements, but from things like should we treat state of affect as a state when a human has no free will.

So, a compatibilist view is not incompatible with the world we live in, but moreover, it is needed to keep our world functioning. The world we live in is mostly artificially constructed. Welfare and justice systems are not "genuine", they are artificial constructs. They play a role in our society and the ideas of "free will" and "guilt" are constructed also, and they are tweaked to make our systems to work better. If you assume that free will and guilt are "genuine" or God given, then you can't tune them to better match their purposes. You are losing agency this way, losing part of your free will, you can't consciously and reasonably discuss if state of affect should be an exception from the rule "any person has a free will". You'll be forced either to skip the discussion, or to resort to some kind of theological arguments.

But if you accept, that "free will" is a social construct, then you can easily identify the affected variables: it is all about punishment for crimes or awarding people for their pro-social deeds. You can think of how "state of affect inhibits free will" can influence all these goals, you can think of the possibility of people simulating state of affect (or even nurturing their personal traits that increase the probability of entering state of affect) to avoid a punishment. You can think rationally, logically and to pick a solution that benefits the society the best. Those very society with baked in idea of free will. Or you can choose to believe "free will" is God given, because of an irrelevant linguistic argument, and lose the ability to make our world better.

> most people act in ways that clearly signal a non-compatibilist view of free will.

Of course, we are not living in quantum mechanics we live in a world that is constructed by people. I mean, all this is built on top of QM, but QM laws do not manifest themselves directly for us. We have other explanatory structures to deal with everyday physics. But even physics doesn't matter that much: I turn the switch and voila I have light, and the heck with conservation of energy. I can talk to you, despite we are residing on different continents, 1000s of km don't matter. If I want to eat I do not try to kill some animal to eat it nor do I gather seeds and roots in a wild to eat them. I go to work and do something, get my salary and buy food in a local store. We are living in an artificial world with artificial rules. Free will is part of this world. Of course we talk about it like it exists. We talk about it like it is a universal truth. Relativity I mentioned above doesn't show itself most of the time, because the world is constructed in a way, when we can agree about someone having it. Situations when this is not the case are very strange and can be even punished: manipulation (which is come close to taking people's agency away from them) is deemed amoral.

The world constructed so we can ignore that free will is just an illusion, moreover it is constructed to think about it in terms of free will, so you'll have issues thinking about it in other terms. Like you'll have a lot of issues trying to calculate aerodynamic of a plane relying on equations of quantum mechanics.

[vidarh]

A compatibilist view, to me, is usually immoral, because it seems to maintain the pretence of agency while admitting it's an illusion, and so persist in accepting treating people as if they have agency.

People who at least genuinely believe in free will and agency has an excuse if they e.g. support punishment that is not strictly aimed at minimising harm including to the perpetrator. A compatibilist has no excuse.

It is of course possible to hold a compatibilist view and still argue we should restructure society to treat people as if they do not have agency, but then the point on holding onto the illusion drops to near zero.

[ordu]

> A compatibilist view, to me, is usually immoral, because it seems to maintain the pretence of agency while admitting it's an illusion, and so persist in accepting treating people as if they have agency.

Is thermodynamics immoral? You see, there is nothing fundamental about pressure or temperature, they are just statistical averages, they are all in imagination, it is an illusion. But we still pretend that pressure and temperature exist.

Or what about biological species? If you look into it, you'll see that there is no clear way to define what species are, all the definitions are imperfect projections of our high-level illusions onto the underlying biology and biochemistry. But we (and biologists also, who much more aware of the issues) still pretend that species exist. Are biologists immoral?

Nothing wrong with it. Nothing immoral, it is just a regular mental tool. You see, the question is what does it mean for thing to exist. Some things are easy: like there is a car, we can see it, we can touch it, we can drive it, therefore we agree that the car exists. But some things are not so easy, especially when we talk about immaterial things. But to make things even more interesting, some things seem to exist on some level, and do not exist on other levels. Like life for example. There is no life in an atom of carbon or hydrogen or nitrogen, but the bunch of such atoms connected just right can be alive. And it normally don't make people jumpy. At the some time some people have issues with the idea that free will exists on some levels but not others.

> People who at least genuinely believe in free will and agency has an excuse if they e.g. support punishment that is not strictly aimed at minimising harm including to the perpetrator. A compatibilist has no excuse.

Yea. I don't believe in free will and agency "genuinely", so I have no excuse. But I believe that any such excuses are borderline immoral. If anyone allows their emotions and animal instincts to take over them and act against the greater good of a society, it is immoral. I mean, if they do it for their own gain, it may be not immoral, there is a tradeoff between interests of a society and interests of an individual, and sometimes we should prefer the former and sometimes the latter. So going against the society interests is not inherently bad. But doing it because of uncontrollable emotions and animal instincts is bad. It still counts as an excuse, but I'm not sure if it is a good thing. I should believe that this is a good thing, because I don't know how to test it experimentally without risking to harm people even more. But still while I can accepts excuses of others, I don't accept such excuses from me. I just don't let myself to let emotions drive without any oversight from me (whatever this "me" is: this is one more interesting question without any good answers).

The point is: my "non-genuine" belief in free will make me much more free willed than a genuine belief. If I succumbed to my emotions and didn't control myself for three seconds, I'd see it as my personal failure. In my head I'm in control, not someone or something else.

> It is of course possible to hold a compatibilist view and still argue we should restructure society to treat people as if they do not have agency

No point in it. It is like arguing "lets forget thermodynamics and resort to pure QM because it is closer to fundamental laws of the Universe". We need the idea of free will, even if it doesn't hold on fundamental level.

[halfcat]

A flawless predictor would indicate you’re in a simulation, but also we cannot even simulate multiple cells at the most fine-grained level of physics.

But also you’re right that even a pretty good (but not perfect) predictor doesn’t change the scenario.

What I find interesting is to change the amounts. If the open box has $0.01 instead of $1000, you’re not thinking ”at least I got something”, and you just one-box.

But if both boxes contain equal amounts, or you swap the amounts in each box, two-boxing is always better.

All that to say, the idea that the right strategy here is to ”be the kind of person who one-boxes” isn’t a universe virtue. If the amounts change, the virtues change.

[danbruc]

A flawless predictor would indicate you’re in a simulation [...]

No, it does not. Replace the human with a computer entering the room, the predictor analyzes the computer and the software running on the computer when it enters. If the decision program does not query a hardware random source or some stray cosmic particle changes the choice, the predictor could perfectly predict the choice just by accurately enough emulating the computer. If the program makes any use of external inputs, say the image from an attached webcam, the predictor also needs to know those inputs well enough. The same could, at least in principle, work for humans.

[vidarh]

I agree with you that it doesn't require that you are in a simulation, but a flawless predictor would be a strong indication that a simulation is possible, and that should raise our assumed probability that we're in a simulation.

[arethuza]

I would think that the existence of a flawless predictor is probably more likely to indicate that memories of predictions, and any associated records, have been modified to make the predictor appear flawless.

[vidarh]

I would say that if we presume memories of everyone involved have been modified, that is an equally strong predictor that we are in a simulation.

[danbruc]

Where does this obsession with the simulation hypothesis come from, it has been so widespread in the last years? It is more or less pointless to think about it, it will not get you anywhere. You only know this universe, to some extend, but you have no idea what a real universe looks like and you have no idea what a simulated universe looks like, so you will never be able to tell which kind our universe is.

But what if we discover that our universe is made from tiny voxels or something like that, that will be undeniable evidence, right? Wrong! Who says that real universes are not made of tiny voxels? It could be [1] the other way around, maybe real universes are discrete but their universe simulations are continuous, in which case the lack of tiny voxels in our universe would be the smoking gun evidence for being in a simulation.

[1] This is meant as an example, I have no idea if one can actually come up with a discrete universe that admits continuous simulations, which probably should also be efficient in some sense.