Hard Determinism refuted?

[trip]

Let's say you set up a lab experiment with a subject, the Laplacean demon that had perfect physical knowledge of the entire universe at T1, and a red and blue button.

Let's say the subject is told to push a button, his choice. Hard Determinists would say that the choice of button pushed is inevitable since the material universe is purely deterministic, and this person's brain is no exception to that. So the demon predicts blue, and of course, the person pushes blue, just as he always had to do.

But let's say the demon told the subject he was destined to push blue, given the state of the universe at that point. The person could just push red at that point of course.

This knowledge is just another prior cause, so it should be able to be integrated into the demon's perfect knowledge and produce a inevitable effect like any other cause, yet this can't happen. And of course the demon can't say "Aha, I told you blue because I knew you would push red given that I told you blue!" The demon has to be upfront with his prediction and not make a secret prediction, unrevealed to the subject.

What does the fact that simply telling us the 'inevitable' future makes the future literally unpredictable?

[Preno]

Claiming that being informed of a prediction can invalidate this prediction is something quite different than claiming that the future is unpredictable.

[Kingreaper]

The laplacean demon must be causally isolated from what it predicts in order to predict with perfect accuracy. But this is obvious.

For a being to affect the world AND predict with perfect accuracy what the world will be almost requires fatalism, whether the being is the fate, or merely chosen by the fate to make perfect predictions.

[trip]

But the information in this case would in fact make the future unpredictable. It would literally render the demon incapable of making an accurate prediction.

"This is obvious" is a dangersous phrase, and not an argument. Why, exactly, would the demon have to be causally isolated?

[Kingreaper]

But the information in this case would in fact make the future unpredictable. It would literally render the demon incapable of making an accurate prediction.

"This is obvious" is a dangersous phrase, and not an argument. Why, exactly, would the demon have to be causally isolated?

It seems obvious to me that anything which is a part of a system cannot completely predict the behaviour of that system, because that would mean predicting it's own behaviour prior to behaving in that way. Including its prediction of its own behaviour. This recursiveness means it shouldn't be possible as far as I can see.

How this refutes determinism I don't know. Determinism doesn't require that it be possible to give someone a prediction of their actions, merely that their actions be determined.

[Karen M]

While the demon is often used as a way if illustrating the point that all human actions are controlled by previous causes, this demon’s ability to predict is not actually hard determinism in and of itself.

Hard Determinism just says that free will is an illusion because all the “choices” people make are really caused by previous events.

The button-presser in your example is still pressing the red or blue button based on previous events, not of his own free will.

[trip]

The title is a bit much, I agree. I guess I can't edit that now.

I don't think that this proves that choices don't have previous causes, just that the choices aren't inevitable, so you'd get a more compatibilist view of freewill.

[TheMathGuy]

Let's say you set up a lab experiment with a subject, the Laplacean demon that had perfect physical knowledge of the entire universe at T1, and a red and blue button.

Let's say the subject is told to push a button, his choice. Hard Determinists would say that the choice of button pushed is inevitable since the material universe is purely deterministic, and this person's brain is no exception to that. So the demon predicts blue, and of course, the person pushes blue, just as he always had to do.

But let's say the demon told the subject he was destined to push blue, given the state of the universe at that point. The person could just push red at that point of course.

This knowledge is just another prior cause, so it should be able to be integrated into the demon's perfect knowledge and produce a inevitable effect like any other cause, yet this can't happen. And of course the demon can't say "Aha, I told you blue because I knew you would push red given that I told you blue!" The demon has to be upfront with his prediction and not make a secret prediction, unrevealed to the subject.

What does the fact that simply telling us the 'inevitable' future makes the future literally unpredictable?

The hidden assumption here is that the Laplacean demon is not itself part of the physical universe, and therefore by telling the subject he is destined to push blue it is somehow invading the universe and altering it, hence potentially invalidating it's own prediction. But now let's suppose the Laplacean demon is contained within the physical universe. Let's also suppose that there is a law of the universe that dictates that whenever a certain person is told he will push the red button, it will cause him to push the blue button, and vice-versa. The universe is still deterministic (he will do the opposite of what he is told he will do), but if a Laplacian demon is built to predict his actions and tell him it's prediction before he does them, then it will of course predict them wrong. All this argument really would show is that a Laplacian demon that tells people what they're going to do before they do it is inconsistent with the physical laws of the universe, and therefore does not exist anywhere within the universe (assuming there are people who can be guaranteed to always contradict any prediction).

This idea is very reminiscent of the proof Gödel's Incompleteness Theorem, which states that any logic system capable of expressing elementary arithmetic cannot be both consistent and complete. The way the proof works is by constructing a proposition that is able to refer back to itself, and to say the mathematical equivalent of the English sentence "This proposition cannot be proven true within the given system." We can tell that the proposition is clearly true (assuming a consistent logic), since if it could be proven true by the system, then it would actually be true, but if it's actually true then it can't be proven true by the system. So it can't be proven by the system, which makes it true. So we can prove it true, but the logic system in question cannot.

So this means that the universe itself, if it is deterministic (therefore forming a consistent mathematical system), and if it is capable of forming basic arithmetic statements (human beings certainly are!), then it will contain 'truths' which cannot be proven true from within the universe itself. So perfect determinism, in the mathematical sense, would also necessarily entail unpredictability (or rather imperfect predictability) from inside of the universe.

[Karen M]

I don't think that this proves that choices don't have previous causes, just that the choices aren't inevitable, so you'd get a more compatibilist view of freewill.

That’s what quantum mechanics are for. ;)

Some causes can have multiple possibilities for an effect, but the effect that actually happens is still caused. And this effect will still go on to cause other events.

[Kingreaper]

The title is a bit much, I agree. I guess I can't edit that now.

I don't think that this proves that choices don't have previous causes, just that the choices aren't inevitable, so you'd get a more compatibilist view of freewill.
In the context inevitability implies fatalism. It implies that there is a will that wishes to prevent the choice, but cannot. In hard determinism such a will could succeed, if it existed, but it doesnt and won't exist.

[sweetiepie]

For a being to affect the world AND predict with perfect accuracy what the world will be almost requires fatalism, whether the being is the fate, or merely chosen by the fate to make perfect predictions.
I don't knwo what you mean by fatalism. It would be something more along the lines of Dune, Harry Potter, Ground Hogs Day.. or something. That is, it would just be a very very very very clever person who knows all the right things to say/do.

[Kingreaper]

I don't knwo what you mean by fatalism. It would be something more along the lines of Dune, Harry Potter, Ground Hogs Day.. or something. That is, it would just be a very very very very clever person who knows all the right things to say/do.
I've never seen Dune, but from what I've heard about it it has self-fulfilling prophecies of sufficient complexity to make it most likely fatalistic.

Harry Potter+the time turners is fatalistic. (time loops are inherently fatalistic)

Groundhogday is mostly deterministic, the butterfly effect seems to apply, but I think there are some bits where you'd expect more divergence than you see.

[Philo_66]

Hard Determinism just says that free will is an illusion because all the “choices” people make are really caused by previous events.
What then is a "choice" or are you saying we don't really make choices?

The button-presser in your example is still pressing the red or blue button based on previous events, not of his own free will.
Do you mean the choice is made for him rather than by him?

Phil

[EricK]

The OP seems internally inconsistent.

Either the Demon is itself determenistic or it isn't.

If it is, then there is no reason to assume that it will be able to tell the subject what choice they will make. Indeed, if we take it as fact that it always makes correct predictions about the universe then we can deduce that it will not inform the subject of their future choice if by telling they would be altering the choice.

But if the Demon is not deterministic but the universe is, then the demon will not be able to affect the universe in any way. Because if it did, the universe would turn out to be not deterministic after all (another demon aware of only the state of the universe a moment before the first demon intervened, would not be able to accurately predict the future state of the universe).

So a deterministic universe is incompatible with a non-deterministic demon who can intervene, and a deterministic demon who can intervene (thus making the demon just a part of the deterministic whole) could not behave as the OP suggests.

[Karen M]

What then is a "choice" or are you saying we don't really make choices?

I’m saying Hard Determinists believe choice is an illusion, yes.


Do you mean the choice is made for him rather than by him?

That depends on what you mean by “for him rather than by him.” From his point of view, he freely chose. Whether or not his personal perception of having a choice really means he ultimately controlled his own actions is debatable.

[Philo_66]

I’m saying Hard Determinists believe choice is an illusion, yes.
Yes, that would be my take on hard determinism and why I would say very few people really hold to it. If this premise is accepted, there is no basis for any of our understanding on intention, will, intelligence, morality, politics, economics, etc, etc. It all comes unraveled.

That depends on what you mean by “for him rather than by him.” From his point of view, he freely chose. Whether or not his personal perception of having a choice really means he ultimately controlled his own actions is debatable.
I'm just asking the question from another angle. I don't think we have 'ultimate' control. We have 'proximate' control, though. Hard determinism denies this proximate control. But that's problematic also. The ultimate cause would always have to go back to the Big Bang. It's not very useful for understanding human behavior to do that.

Phil

[untermensche]

Yes, that would be my take on hard determinism and why I would say very few people really hold to it. If this premise is accepted, there is no basis for any of our understanding on intention, will, intelligence, morality, politics, economics, etc, etc. It all comes unraveled.
We have no understanding of intention or will. We have no anatomical or physiological explanation of either.

[Philo_66]

We have no understanding of intention or will. We have no anatomical or physiological explanation of either.
That doesn't mean it doesn't exist, though, right? It does mean, I think, that we need better definition or better understanding.

Phil

[Guttersnipe]

Yes, that would be my take on hard determinism and why I would say very few people really hold to it. If this premise is accepted, there is no basis for any of our understanding on intention, will, intelligence, morality, politics, economics, etc, etc. It all comes unraveled.

I've been a disbeliever in free will for about 8 years. I have yet to see an adaquate explanation of how 'free will' works on a causal level with our actions, which has made me inclined to think that the idea isn't entirely cogent. In any case, there can be an understanding of the issues you mentioned, but ideas such as ultimate responsibility and retributivism are clearly unjustified to determinists. One of the reasons I think compatablism is so popular is that many philosophers feel the need to reconcile determinism with moral responsibility. Tho I personally view compatablism as a sugar coated version of hard determinism.

[trip]

We have no understanding of intention or will. We have no anatomical or physiological explanation of either.

Then we have to be careful of a "Philosophy of the Gaps" argument, that is, assuming we actually know about these things based on 'armchair' philosophizing, using logical arguments sans any actual empirical knowledge about the topics under discussion, especially when those arguments lead us to conclusions that fly in the face of our prima facie thinking about of reality.

[Philo_66]

Then we have to be careful of a "Philosophy of the Gaps" argument, that is, assuming we actually know about these things based on 'armchair' philosophizing, using logical arguments sans any actual empirical knowledge about the topics under discussion, especially when those arguments lead us to conclusions that fly in the face of our prima facie thinking about of reality.
Exactly... "sans any actual empirical knowledge about the topics under discussion." Which could mean any one of several things:
a) our prima facie thinking about reality is flawed.
b) our concept of determinism (ie, cause and effect) is flawed
c) our concept of free will is flawed
d) all of the above.

I'm going with d. We have good reason to suspect reality ain't exactly what we think it is.

Phil

[untermensche]

That doesn't mean it doesn't exist, though, right? It does mean, I think, that we need better definition or better understanding.

Phil
It may not exist on the personal level as we believe.

"Will", that is.

[EricK]

We have no understanding of intention or will. We have no anatomical or physiological explanation of either.

In his book "The Human Mind" Robert Winston says
Neurologist Antonio Damioso described one patient who, after a stroke, had damage to the frontal lobes and lay for several months without speaking or moving. When she eventually recovered, she said that during her period of immobility she had not felt that she couldn't do anything, but that she hadn't wanted to.
That suggests we do have some anatomical explanation of intention and will.

[untermensche]

In his book "The Human Mind" Robert Winston says

That suggests we do have some anatomical explanation of intention and will.
You say it is the frontal lobe?

But in Parkinson's patients the problem is in the substantia nigra.

And they too have great difficulty initiating movement.

I think the problem of initiation of movement is far from explained in anatomical and physiological terms, except in the most general manner.