And yet the real instances of flipping fair coins produce this kind of distribution. Very similar to sex proportions in birth. — fdrake

If we flip a coin a thousand times, we can be pretty confident that 50% of the flips will be heads. If we lack confidence in logic, we can do it and then be happy that we can predict the future.

If we flip one coin, we know zero, nada, not-a-fucking-thing about the outcome (unless the system is rigged or we have Laplace's demon on hand.) I'm sure you agree with that?

The claim that 'if we knew all relevant information then the future would be fixed' isn't inconsistent with 'probability; when what flipping a coin is contains that uncertainty about the future.

Who is doing all this knowing? Where is it in the system? — fdrake

I don't understand what you're asking.

As I've said, there are times when knowing all relevant information isn't possible, even in theory. Even if it were possible, that information would also have to be processed in order to make a prediction. — T Clark

If we flip one coin, we know zero, nada, not-a-fucking-thing about the outcome (unless the system is rigged or we have Laplace's demon on hand.) I'm sure you agree with that? — frank

You actually know quite a lot about the outcome. It's described as 50% heads 50% tails. We don't know what the outcome is but we have a complete specification of the system; all relevant info is encoded there, right? Anyway.

Let's look at determinism as captured in Wayfarer's quote of Laplace.

We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom... — Wayfarer

From which you can distill two principles.

(1) If you have a complete specification of a system at some time t, then it is specified for all times before t and after t. Positions, momenta, orientations, that kind of thing.
(2) The specification procedure for all preceding and following states can be obtained by 'submitting the data to analysis'. Presumably this is a codification of all relationships of the basic variables of nature that entail everything about everything else given sufficient manipulation.

and from the remainder of the quote.

for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.

(3) In such a description, nothing would be uncertain (for the subject of 1 which has the specification procedure in 2).

I wanna say that (1) is purely an ontological claim; it concerns the nature of nature/being/One/All/Many/process/stuff/whatever. (2) is talking about a codification of the information in (1), if it can all be distilled into some placeholder. It is how the 'complete' specification' in (1) would be articulated. Then we have that if (1) is true and (2) exists, nothing would be uncertain for that intellect.

So there's a lot going on there. (1) and (2) together still look like determinism, and don't have any epistemic valences. But (3) uses 'uncertain' in a colloquial sense, as in 'there is nothing which could not be known/predicated/anticipated' by the intellect.

We know that (1) is false, so long as we take a realist interpretation of the wavefunction in quantum mechanics. It might fail for other reasons too, but this suffices. There's randomness in nature.

Interestingly (2) also seems to be false, at least if we make the assumption that the grand complete specification in Laplace's formulation is the result of an algorithm, anyway. And not some divine act of comprehension.

I know this doesn't really clear up much of the relationship between uncertainty and determinism, or randomness and determinism, but hopefully it provides a useful distinction between what's going on in (1), (2) and (3).

You actually know quite a lot about the outcome. It's described as 50% heads 50% tails. We don't know what the outcome is but we have a complete specification of the system; all relevant info is encoded there, right? Anyway. — fdrake

Assuming no asteroids interfere and so on, we feel confident that the outcome will be either fully and completely heads or fully and completely tails. So we know an if/then statement.

Think about what question 50%/50% is actually answering.

I know this doesn't really clear up much of the relationship between uncertainty and determinism, or randomness and determinism, but hopefully it provides a useful distinction between what's going on in (1), (2) and (3). — fdrake

Chalmers uses Laplace's demon in a rambling book about constructing worlds. He modifies it to cover objections. I don't have that book anymore, though.

If we flip a coin a thousand times, we can be pretty confident that 50% of the flips will be heads. If we lack confidence in logic, we can do it and then be happy that we can predict the future. — frank

Actually, if I flip a coin 1,000 times, it's unlikely that exactly 50% of the flips will be heads. It is certain, though, that if I flip 1,000 times and it isn't 50/50, if I keep flipping, it will eventually even out to 50/50. I'm not trying to nitpick here. It seems to me to be a pretty important distinction.

If we flip one coin, we know zero, nada, not-a-fucking-thing about the outcome (unless the system is rigged or we have Laplace's demon on hand.) I'm sure you agree with that? — frank

As @fdrake says, knowing that there is a 50/50 chance it will come up heads is not "nada." It's more than we know about lots of things that are a lot more important than coin flips.

As fdrake says, knowing that there is a 50/50 chance it will come up heads is not "nada." It's more than we know about lots of things that are a lot more important than coin flips. — T Clark

50/50 is an assessment of a formal system, not the outcome of a unique coin toss.

Maybe it would help if we considered an unbalanced object. It has a 97% chance of coming up heads. What does 97%/3% tell you about a unique toss?

(1) If you have a complete specification of a system at some time t, then it is specified for all times before t and after t. Positions, momenta, orientations, that kind of thing.

(2) The specification procedure for all preceding and following states can be obtained by 'submitting the data to analysis'. Presumably this is a codification of all relationships of the basic variables of nature that entail everything about everything else given sufficient manipulation....

(3) In such a description, nothing would be uncertain (for the subject of 1 which has the specification procedure in 2). — fdrake

Which brings us back to the point I've been trying to make. In sufficiently complex systems, which are not all that complex, (1) and (2) are not humanly possible and therefore (3) is false.

a football ....(which is very spherical) — fdrake

As everyone knows, a football is not spherical, it is oblong with pointy ends.

50/50 is an assessment of a formal system, not the outcome of a unique coin toss.

Maybe it would help if we considered an unbalanced object. It has a 97% chance of coming up heads. What does 97%/3% tell you about a unique toss? — frank

It tells me that, if I bet $1.00 on the fair coin, the expected value of the bet for me is $1.00. If I bet on the unfair coin and I call heads, the expected value is $1.94.

The usual criticism of pragmatism is that it conflates truth with belief. Realists will say that there are truths which are unknown, and that truth in general is independent of what anyone believes. In other words they will say, contra pragmatism, that propositions are true, not because we believe them, but on account of their accordance with reality. I tend towards being a kind of relational, or indirect, realist myself.

In any case the truth of any philosophical position can never be proven.

Thanks for your explanation. It's still not clear to me why you think,assuming that the physical world is completely deterministic, chance could come into it, other than conceptually in relation to our predictions.

Take the "football" example. If the ball is not perfectly spherical then it will not be pure chance even in relation just to the ball itself, without considering any external forces, what part of its surface it comes to rest on. Even if a ball were perfectly spherical, where it comes to rest would be completely determined by forces external to it, and thus not at all a matter of chance.

The only element of chance or probability I can imagine would be if nature is, at a microscopic level nondeterministic, which would seem to entail that macroscopic outcomes, although very close to being deterministic, would nonetheless have a tiny element of chance influencing them.

In any case the truth of any philosophical position can never be proven. — Janus

I've said this several times previously in this thread - this is a metaphysical/epistemological issue. There is no proving required. It's a question of usefulness, meaningfulness, value. What is the value of the "realist" approach in this instance. What value is there in talking about something that we can think about happening but which can never actually happen. What does it contribute to knowledge, wisdom, effective action. That's probably a pragmatist's question.

It is my understanding that QM is considered a deterministic theory. — T Clark

I don't believe so. I think the 'uncertainty principle' slays LaPlace's daemon. So it's directly relevant to the issue.

Who is doing all this knowing? Where is it in the system? — fdrake

It's a theoretical projection based on the principle of what an all-knowing mind would know. As Hawkings famously said, 'If we discover a complete theory, it would be the ultimate triumph of human reason – for then we should know the mind of God.'

I think the 'uncertainty principle' slays LaPlace's daemon. It's directly relevant to the issue. — Wayfarer

I didn't say it wasn't relevant, I said that, as I understand it, QM is considered deterministic. I just went and looked on the web. Apparently that is not completely true - some say it am and some say it ain't. However we come down, I don't think it has any impact on my position.

But it does, T. Clark. It's not that far from what you're saying about the impossibility of being able to know all of the factors that collectively bring about an outcome ruling out the possibility of Laplace's Daemon. However the crucial difference with your argument is that, according to the uncertainty principle, at least some of the factors are not actually existent, or not objectively real, until such time as they are measured. So it's not as if the all-seeing mind could predict how those entities are going to act in advance, as the act of perceiving them is implicated in the outcome. So they're in some sense un-knowable in principle; not simply not perceived.

And that, of course, is one of the principle tenets of the Copenhagen interpretation of physics, of which Werner Heisenberg was one of the chief proponents. It undermines determinism. (Actually I have just learned that if you begin to search Copenhagen interpretation and det.... that google remembers the query and fills in the last word - which tells you something!)

I recommend having a peruse of Heisenberg's Physics and Philosophy, forward by Paul Davies. It's freely available as a PDF. It was written in the fifties and is not an especially arduous read, and is philosophically acute, in my humble opinion.

In fact, following that google query, the first sentence of the 'featured response' is 'This fundamental limitation [i.e. of the uncertainty principle] represents a breakdown of determinism in nature.'

As I understand, in accordance with the most common interpretations, the epistemological question is "What do we know and how do we know it?", and the metaphysical question is "What is there, and is it independent of our perceiving/knowing it?".

Of course, we can have one view or the other regarding both of these questions, and there is no question of "proof" as you have agreed. Is there any truth in these matters? If so, is the truth ultimately a matter of consensus, as pragmatism would have it? Or is it a matter of mere personal preference; what works for me or you? Is it a matter of plausibility, and if it is, how do we derive a standard of plausibility that is not itself a matter of mere preference or consensus?

As you can probably tell I am somewhat of a skeptic who leans towards realism.

Think more simply. When something is ‘determined’ it is known, and when something is predicted it is ‘guessed’ based of determined knowledge (educated guess).

People playing at philosophy will always try and put their own special spin on it to make themselves feel validated.

As for “ontology” and “epistemology”, I agree. They are the same thing and it is merely a convenient demarcation of speech - the underlying game of philosophy where the physicist doesn’t much bother themselves with such - to be frank - tail chasing drivel (and nor do philosophers of any substance).

Think more simply. When something is ‘determined’ it is known, and when something is predicted it is ‘guessed’ based of determined knowledge (educated guess).

People playing at philosophy will always try and put their own special spin on it to make themselves feel validated.

As for “ontology” and “epistemology”, I agree. They are the same thing and it is merely a convenient demarcation of speech - the underlying game of philosophy where the physicist doesn’t much bother themselves with such - to be frank - tail chasing drivel (and nor do philosophers of any substance). — I like sushi

But it does, T. Clark. It's not that far from what you're saying about the impossibility of being able to know all of the factors that collectively bring about an outcome ruling out the possibility of Laplace's Daemon. — Wayfarer

I think I agree with your interpretation but, again, it doesn't have any impact on my position. It's just another example of the case I am trying to make - if it ain't predictable, it ain't deterministic.

So it's not as if the all-seeing mind could predict how those entities are going to act in advance, as the act of perceiving them is implicated in the outcome. So they're in some sense un-knowable in principle; not simply not perceived. — Wayfarer

I don't think either you or I know exactly what God can and cannot do.

And that, of course, is one of the principle tenets of the Copenhagen interpretation of physics, of which Werner Heisenberg was one of the chief proponents. It undermines determinism. (Actually I have just learned that if you begin to search Copenhagen interpretation and det.... that google remembers the query and fills in the last word - which tells you something!) — Wayfarer

Here's what the Stanford Encyclopedia of Philosophy says about QM being deterministic:

So goes the story; but like much popular wisdom, it is partly mistaken and/or misleading. Ironically, quantum mechanics is one of the best prospects for a genuinely deterministic theory in modern times! Everything hinges on what interpretational and philosophical decisions one adopts. The fundamental law at the heart of non-relativistic QM is the Schrödinger equation. The evolution of a wavefunction describing a physical system under this equation is normally taken to be perfectly deterministic. If one adopts an interpretation of QM according to which that's it—i.e., nothing ever interrupts Schrödinger evolution, and the wavefunctions governed by the equation tell the complete physical story—then quantum mechanics is a perfectly deterministic theory. There are several interpretations that physicists and philosophers have given of QM which go this way.

I'm not taking a position on this. I'm only using it as evidence that not everyone agrees that QM undermines determinism. In terms of my argument, whether or not other people say it is deterministic, I say it's not because events at the atomic level are not predictable under either classical or quantum mechanics.

Wait - I like this one better.

As I understand, in accordance with the most common interpretations, the epistemological question is "What do we know and how do we know it?", and the metaphysical question is "What is there, and is it independent of our perceiving/knowing it?".

Of course, we can have one view or the other regarding both of these questions, and there is no question of "proof" as you have agreed. Is there any truth in these matters? — Janus

Agreed.

Is there any truth in these matters? If so, is the truth ultimately a matter of consensus, as pragmatism would have it? Or is it a matter of mere personal preference; what works for me or you? Is it a matter of plausibility, and if it is, how do we derive a standard of plausibility that is not itself a matter of mere preference or consensus? — Janus

Just to be clear, you are referring to metaphysical and epistemological truths, is that correct? If so, then yes, it's a matter of preference or consensus. If we're going to try to work something out together, we have to come to an agreement on these issues, which provide the underlying rules of the game. Otherwise, we'll just spin our wheels, as so often happens on the forum.

If one adopts an interpretation of QM according to which that's it—i.e., nothing ever interrupts Schrödinger evolution, and the wavefunctions governed by the equation tell the complete physical story—then quantum mechanics is a perfectly deterministic theory.... — T Clark

...according to the 'relative state formulation' of Hugh Everett, which, however, requires that the universe 'branches' every time an observation is taken.

...according to the 'relative state formulation' of Hugh Everett, which, however, requires that the universe 'branches' every time an observation is taken. — Wayfarer

Again, my only point in this regard is that some believe QM is deterministic. I have no position on any of those arguments. My position is that since atomic events are not predictable under either quantum or classical mechanics, it makes sense to consider them non-deterministic. That is the intended substance of this thread.

There is a point....where "completely outside the scope of human possibility" turns into "not possible even in theory."
— T Clark

At that point, in my, and others, opinions, it stops being deterministic. — T Clark

It seems to me that if you are making the case that something is the case because something else is the case, then you are making the case for determinism.

If something is completely outside the scope of human possibility and that makes it not possible in theory, and that makes the case that there isn't determinism, then you just made the case for determinism. If there are cases that logically follow other cases, or that there are reasons that you point to for your ideas, then you are making the case for determinism. It seems to me that in order to be logical, you can't escape being deterministic.

Possibilities are ideas in someone's head that can either be reflective of actual states of affairs, or not (imaginings). What exactly is outside the scope of human possibility? How would we know such a thing?

It's a theoretical projection based on the principle of what an all-knowing mind would know. As Hawkings famously said, 'If we discover a complete theory, it would be the ultimate triumph of human reason – for then we should know the mind of God.' — Wayfarer

Going out on a limb here.

I guess what I'm gesturing towards is why should we care about the perspective of God on a system when God's external to it? It's a question of how structures are internalised to systems, rather than abstracting away from the details of all of them. So in my question to @frank, "who's doing the knowing?", who does the knowing that vouchsafes this kind of determinism? It can't be located within a functionally bounded system - one which has demarcated modes of operation, it can only be the totality of all things viewed from the perspective of that infinite intellect.

Thanks for your explanation. It's still not clear to me why you think,assuming that the physical world is completely deterministic, chance could come into it, other than conceptually in relation to our predictions. — Janus

Well randomness doesn't have to be like the popular notion of it. Random variables are just normalised measurable functions on some sigma-algebra of events. The sigma algebra of events can be (associated with) a deterministic dynamical system, and there will still be random variables induced by the transitions of this dynamical system. Like the Bernoulli distribution emerges out of deterministic coin flipping (probably due to initial condition sensitivity of the flipping dynamics). Randomness is much more like forgetting some parts of a system's structure through suitable aggregation of its events than unstructured exceptions to linear notions of cause.

, who does the knowing that vouchsafes this kind of determinism? — fdrake

It's just folk wisdom that the mead you're drinking isn't going to turn into petroleum on its way down your throat without a knowable explanation.

How is our confidence in that justified? Opinions vary, but I don't think anyone believes it's dependent on somebody knowing something.

It seems to me that if you are making the case that something is the case because something else is the case, then you are making the case for determinism.

If something is completely outside the scope of human possibility and that makes it not possible in theory, and that makes the case that there isn't determinism, then you just made the case for determinism. — Harry Hindu

Two problems with this. 1) I'm talking about physical determinism, you're talking about logical determinism. Not the same thing at all. 2) I've made it clear that I'm talking about complex systems. I used an example, billiard balls, where a case can be made for predictability and determinism. You don't have to go much up the ladder of complexity before direct empirical predictability is lost and we are left to deal with probabilities. I'm using the words "direct" and "empirical" to mean predictability made possible by actually tracking the positions of particles and calculating future conditions. I'm not sure if those are the right words to use.

What exactly is outside the scope of human possibility? How would we know such a thing? — Harry Hindu

Good point. I've tried to make the case that, in all but the simplest systems, empirical predictability is not humanly possible. If I flip a coin 1,000 times, there are 2^1,000 possible combinations of results, each with equal probability. That''s about 1 x 10^300. Web says there are about 1 x 10^80 atoms in the visible universe. That's what I mean by "outside the scope of human possibility."

It's just folk wisdom that the mead you're drinking isn't going to turn into petroleum on its way down your throat without a knowable explanation.

How is our confidence in that justified? Opinions vary, but I don't think anyone believes it's dependent on somebody knowing something. — frank

You're oversimplifying and you're stepping outside the bounds of the specific definitions of "determinism" used in the OP which, as I said, are:

* A system is deterministic just in case the state of the system at one time fixes the state of the system at all future times. A system is indeterministic just in case it is not deterministic.

* Causal determinism is, roughly speaking, the idea that every event is necessitated by antecedent events and conditions together with the laws of nature.

* Determinism is the understanding that all events, including moral choices, are completely determined by previously existing causes. — T Clark

I guess what I'm gesturing towards is why should we care about the perspective of God on a system when God's external to it? It's a question of how structures are internalised to systems, rather than abstracting away from the details of all of them. So in my question to frank, "who's doing the knowing?", who does the knowing that vouchsafes this kind of determinism? It can't be located within a functionally bounded system - one which has demarcated modes of operation, it can only be the totality of all things viewed from the perspective of that infinite intellect. — fdrake

I think I understand what you're saying and I think I agree with you. Could you clarify a bit for someone barely literate in probability and statistics. Terms I could use help with - "structures are internalized;" "functionally bounded system;" and "demarcated modes of operation."

Terms I could use help with - "structures are internalized;" "functionally bounded system;" and "demarcated modes of operation." — T Clark

Thank you for your patience. These are still things I'm wrestling with, and it is very good to have someone who is actually interested in my wrestling with them.

"Structures are internalised" isn't something really statisticsy, I guess I just used it as a placeholder. We might say that electrical flow is an 'internalised structure' of a circuit, so are the wires and conductivity, voltages, currents, their relationships. They don't have much to do with nuclear bombs or sledgehammers or wire cutters even though they can all destroy circuits.

"Functionally bounded system" is another placeholder. Whenever you find some system behaving in some way, it behaves in the ways it does rather than in all ways it could behave. Realising any counterfactual of a system seems to require either further evolution along one of its trajectories; like time increasing in heat dissipation of an object as a function of time making the object go to about the environmental temperature. Or the introduction of a new regime of behaviour relevant to the previously established one; like when enzymes lock with their substrates and go from floating proteins (orientations of proteins and position and their time changes) to part of the molecular factory of digestion (enzymes working to produce nutrients). That "Or" is not an exclusive or.

When you have an infinite intellect, nothing really realises in the first sense (within the same regime) and nothing really novel happens (no new regimes), so we're left with a completely timeless completely described blob.

"demarcated modes of operation" was another placeholder. Imagine you disperse some amylase in solution with some starch molecules. Both the starch and the amylase are jiggling about independently for the most part. If you were to model their positions and velocities and orientations, they'd keep on wiggling along indifferent to each other until... they got close, and one breaks the other apart. The starch and the amylase have demarcated modes of operation; moving about independently; until they get sufficiently close to interact (yielding a new regime of behaviour). Their movements may as well be different dynamical systems until they interact, and these two independent subsystems are demarcated modes of operation within the starch-amylase system.

Thanks for the clarification. I think I understand what you're trying to say and I agree up to a point. I guess it all comes back to

why should we care about the perspective of God on a system when God's external to it? — fdrake

The substance of my position is, if I don't believe there is an omniscient God watching and keeping track of everything all the time, and, if I believe it is not humanly possible to empirically predict any but the simplest systems, then saying the world is determined is not useful or even meaningful.

On the other hand, if I do believe in such a God, I think I would accept the case for determinism.