I'm trying to stick to simple ideas because you are easily confused. Just saying that stochastic phenomena look like a duck.

Just said that stochastic phenomenon look like a duck. — Olivier5

Okay, so irrespective of the actual physics, if we use stochastic methods to model them, they're random. So when I said:

if you are aware that stochastic methods are used to model deterministic processes and yet insist that anything modelled stochastically is random, you do give up the right to be taken seriously — Kenosha Kid

you really were insisting that anything modelled stochastically is random, irrespective of whether it is.

What part of

Maybe that's what it is ontologically. Or maybe not, but ontology is for metaphysicians.

did you fail to understand?

I understand why you're evading the question, but even you must see this is horrifically inconsistent. On the one hand, things seem deterministic but, because of small error, the thing itself is non-deterministic. On the other hand, we might not be able to say anything about the thing itself, but if you can use stochastic methods it is, again, non-deterministic. Your argument is a black box: it doesn't matter what goes in, non-determinism comes out. This classifies it as a religious belief for me.

Yours is a pre-kantian argument about the true essence and nature of things. It may be good metaphysics for demons and for risk-adverse folks, but it not good enough for me.

At best, your essentialist argument forces you to look for patterns in the noise, and that's a good thing. Nobody should ever stop at apparent randomness. Of course it's a good thing to try and understand further a stochastic phenomenon and to do that, postulating some hidden order as a working hypothesis is a prerequisite. But a working hypothesis is quite different from some absolute cosmic ontological a priori statement...

But a working hypothesis is quite different from some absolute cosmic ontological a priori statement... — Olivier5

But in the Copenhagen interpretation the probabilistic model really is only just a working hypothesis. Ontologically there is Heisenbergs uncertainty principle which states that certain properties cannot be measured without influencing the system (i.e. shoot photons at other small bodies without playing billiard) or measure a frequency exactly at a given point in time (as frequency is defined as N/dt).
What you seem to do is to take an interpretation which states itself "this is NOT the reality but just a model", say "look! the reality is probabilistic" and then even come back at people who point out, that without getting metaphysical, you cannot even make the statement that "6 of 10 cases" equates to 60% "probability".

I understand why you're evading the question, but even you must see this is horrifically inconsistent. On the one hand, things seem deterministic but, because of small error, the thing itself is non-deterministic. — Kenosha Kid

I dunno. If Olivier5 wants to interpret things as he does this has to be accepted I guess. If there appears to be a 60% probability of something happening declaring that appearance for the truth is surely not unthinkable. God himself does not know where that photon is, then. One could argue about the value of such a theory but there is no logical reason to reject it per se. Of course it cannot be proven and such proofs can be pointed out as fallacious.

Of course it cannot be proven — Heiko

The important point to realize is that neither determinism nor indeterminist can ever be proven true or false, as they are statements about the ultimate nature of reality. So we don't need to worry about it. It's a bit like the sex of angels.

The important point to realize is that neither determinism nor indeterminist can ever be proven true or false, as they are statements about the ultimate nature of reality. — Olivier5

Oh, the importance of points is again something that is based on value, not on truth. Didn't you point out such a thing as problematic?

Didn't you point out such a thing as problematic? — Heiko

No, I didn't.

That may well be the case. But people who do not care about truth don't usually succeed very long. — Olivier5

I take that as a critical statement then and return the favor. No hard feelings.

Sorry, I don't understand.

Yes, that is the measurement problem. At a given time, we know how much of the wavefunction should be |decayed> and how much |undecayed> but we don't know which we'll see when we measure. — Kenosha Kid

And that's a fundamental problem. I.e. we cannot just improve our measuring apparatus in some way. Either we come up with new physics, or this stays, whether it's an actual ontological reality or not?

That would still be selected for. Sickle cell disease is an example. It confers a survival disadvantage in and of itself, but ends up making the odds of survival greater. If sickle cell disease conferred no survival benefit due to immunity from malaria, it would have been eliminated from the genome due to its survival disadvantage. — Kenosha Kid

That's not necessarily a definition of "selected for" that I'd be comfortable with, but we can probably differentiate in at least three categories: Traits directly selected for based on a fitness advantage, Traits indirectly selected for based on a fitness advantage of a linked Trait, and random traits.

Your second sentence is problematic though. There is no evolutionary mechanism by which traits that confer a fitness disadvantage are removed. The populations were those are present either die out or they don't. If they don't die out, because the selection pressure isn't strong enough, the trait will endure as well.

Which is back to the non-determinism of the gaps: anywhere where it might show its face it is obliged to hide in tiny error bars. — Kenosha Kid

I think that's a matter of perspective. A bayesian might well argue that far from the world appearing to be deterministic, it actually appears probabilistic. That from an epistemological perspective, nothing like the surety that determinism theoretically provides actually exists for practical applications.

And that's a fundamental problem. I.e. we cannot just improve our measuring apparatus in some way. Either we come up with new physics, or this stays, whether it's an actual ontological reality or not? — Echarmion

That's right, which is why I cited the measurement problem as a potential disproof of determinism. Unfortunately we don't have a testable theory of measurement to see whether it is random (Copenhagen-like) or deterministic (MWI-like).

There is no evolutionary mechanism by which traits that confer a fitness disadvantage are removed. — Echarmion

Yes there is: death!

A bayesian might well argue that far from the world appearing to be deterministic, it actually appears probabilistic. — Echarmion

I would wonder why he was arguing anything unless he was pretty certain he'd be understood.

A bayesian might well argue that far from the world appearing to be deterministic, it actually appears probabilistic. — Echarmion

This has been cropping up in both conversations currently touching on determinism, so for the sake of getting a different perspective, I'll ask again here - am I missing something in not seeing this relationship? Determinism is the theory that every event is the result it's causes, probabilistic thinking (or stochastic for that matter) is about our ability to know with certainty what that event will be given the causes. The two are not only mutually compatible, they're not even in the same subject area, I'm lost as to why they keep getting treated as mutually exclusive options for the 'way the world is'.

Determinism is the theory that every event is the result it's causes, probabilistic thinking (or stochastic for that matter) is about our ability to know with certainty what that event will be given the causes. The two are not only mutually compatible, they're not even in the same subject area, I'm lost as to why they keep getting treated as mutually exclusive options for the 'way the world is'. — Isaac

Yes, the net is being cast very broadly in what constitutes randomness. Our ignorance, the complexity of the system, and the sensitivity of its laws to initial conditions are apparently all the same thing as wavefunction collapse. Seek and ye shall find.

Determinism is the theory that every event is the result it's causes, — Isaac

That is the definition of causality, not determinism. Maybe we should try and define what we are talking about a bit better. My understanding is that determinism requires that every given set of causes results in one and only one possible set of effects. The effect is determined in the sense that the solution to the equation is always supposed to be unique.

If a given set of causes can result in several possible effects, then the effects are not fully determined and thus we are in an indeterminist outlook.

Perhaps it's a matter of different definitions of the terms.

The strictest form of determinism would be a mechanical determinism, where the state of the system at any given time can be exactly known if the state at one specific time is known. That would mean events are "mechanically" connected, so that each event has fixed connection to each other event.

The strictest form of non-determinism would be a world where events have absolutely no connection whatsoever.

Is it conceivable that there is a world where events have connections, but the connections are not mechanical? That is, for a given state at T0, more than one future state of the system is possible?

Edit: that's all still presuming time, events and states are ontological categories, which they might not be.

Is it conceivable that there is a world where events have connections, but the connections are not mechanical? That is, for a given state at T0, more than one future state of the system is possible? — Echarmion

Yes, that's the Copenhagen interpretation of quantum mechanics.

every given set of causes results in one and only one possible set of effects...If a given set of causes can result in several possible effects, then the effects are not fully determined and thus we are in an indeterminist outlook. — Olivier5

I've not heard this definition anywhere - perhaps you could cite a source? The key aspect is the bolded terms. I've heard no-one ever talk about determinism in terms of 'given' causes, only in terms of 'actual' causes. It's would be an utterly ludicrous claim and refuted within seconds, to say that any 'given' set of causes will result in only one outcome - all I have to do to refute that is give an insufficient set of causes. say a coin flip where the only cause I give is the movement of the thumb doing the flipping (nothing about air turbulence, coin weighting etc). I seriously doubt anyone believes that.

Is it conceivable that there is a world where events have connections, but the connections are not mechanical? That is, for a given state at T0, more than one future state of the system is possible? — Echarmion

Certainly conceivable, I think, but our inability to determine future states based on states at T0 is of uncertain ancestry, we don't know why we don't know. That's why I think the link between our uncertainty (probabilistic relations) and determinism (the nature of those relations, of which our theories are just models) is a poorly supported one.

Any useful injection of an indeterministic interpretation of uncertainty at a macro scale has to compete with (and posit alternatives to) physical causation. The neurological basis of decision-making, for example, which started this discussion, needs, under indeterministic interpretations, some mechanism whereby physical action is brought about without physical causation. QM is often invoked as the mechanism, but so far resolves to classical mechanics at a cellular scale, so cannot account for it.

The alternative explaination for uncertainty (there are literally millions of neurons firing at once and each takes a slightly different route and has done since birth, hence chaos). Requires the invention of no mechanism not already posited and explains the phenomena without flaw.

So, insofar as we don't know what the source of our uncertainty is, it seems odd to invoke new mysterious mechanisms when the ones we already have explain it perfectly well.

The strictest form of determinism would be a mechanical determinism, where the state of the system at any given time can be exactly known if the state at one specific time is known. That would mean events are "mechanically" connected, so that each event has fixed connection to each other event. — Echarmion

Your use of the word "system" in this post is somewhat misleading. "System" implies boundaries which distinguish internal from external, but the boundaries are positioned according to the judgement of the modeler. Therefore the distinction between the features which are internal to the system and the features which are external to the system is subjective, dependent of the intentions of the modeler.

Is it conceivable that there is a world where events have connections, but the connections are not mechanical? That is, for a given state at T0, more than one future state of the system is possible? — Echarmion

Here, you seem to be referring to a system with no causes external to the system, external causation not being allowed for by your description of possible events within the system. But such a system, which is closed in an absolute way, is not a realistic proposition.

The relativistic knowable universe encompasses X ly around the spectator. The next year it is X+1 ly. How would someone account for the things that have not yet appeared as causes?

I've not heard this definition anywhere — Isaac

Well, Echarmion put the same idea much better than I could, so let's use his characterisation:

That is, for a given state at T0, more than one future state of the system is possible — Echarmion

The neurological basis of decision-making, for example, which started this discussion, needs, under indeterministic interpretations, some mechanism whereby physical action is brought about without physical causation. QM is often invoked as the mechanism, but so far resolves to classical mechanics at a cellular scale, so cannot account for it. — Isaac

I don't think this is a proven fact. Pretty large molecules have been found to display wave-particle duality, for instance. This said, I personally doubt the explication for "the hard problem" is as simple as quantic physics. There's a lot more we don't know in there.

Yes, that's the Copenhagen interpretation of quantum mechanics. — Kenosha Kid

So it's at least not absurd to assume some amount of ontological "randomness".

Certainly conceivable, I think, but our inability to determine future states based on states at T0 is of uncertain ancestry, we don't know why we don't know. That's why I think the link between our uncertainty (probabilistic relations) and determinism (the nature of those relations, of which our theories are just models) is a poorly supported one. — Isaac

As I alluded to a few pages ago, it seems to me that the question of whether the universe is "actually" deterministic is ill conceived. It makes no practical difference to our ability to make predictions.

Any useful injection of an indeterministic interpretation of uncertainty at a macro scale has to compete with (and posit alternatives to) physical causation. — Isaac

Physical causation is an interesting term. Is causation physical? Because causation doesn't actually seem to describe a physical process. It seems more like a value judgement by which we identify some part of the web of physical processes as the "cause" and another as the "effect".

The neurological basis of decision-making, for example, which started this discussion, needs, under indeterministic interpretations, some mechanism whereby physical action is brought about without physical causation. QM is often invoked as the mechanism, but so far resolves to classical mechanics at a cellular scale, so cannot account for it. — Isaac

It's unclear to me what it means for "indeterminism to resolve to determinism at a cellular scale", except as a statement on our ability to predict outcomes. Physically, what actually happens always happens at the micro scale. The macro scale is a human construct. Not some arbitrary fantasy, of course, but still an abstraction based on our particular sensory and mental apparatus.

I'd agree with you in that the indeterminism we observe in physics doesn't really lend itself to a useful notion of free will. But it's still inherent in what happens in the brain, even if we can ignore it for the purpose of explaining human behaviour so far.

The alternative explaination for uncertainty (there are literally millions of neurons firing at once and each takes a slightly different route and has done since birth, hence chaos). Requires the invention of no mechanism not already posited and explains the phenomena without flaw.

So, insofar as we don't know what the source of our uncertainty is, it seems odd to invoke new mysterious mechanisms when the ones we already have explain it perfectly well. — Isaac

Could you explain what you refer to as "our uncertainty" here? I don't really follow.

So it's at least not absurd to assume some amount of ontological "randomness". — Echarmion

Not at all. It is possible that determinism holds at a statistical level. As I've said a few times, if we ever devise a test to discern whether QM is Copenhagen-like or MWI-like that is inconsistent with the latter, I would consider fundamental determinism falsified.

Until then, we cannot use QM as evidence for or against determinism. And there's no other player in the game. Unknown variables, chaotic systems, the inevitable error bars before and after, these all lead to behaviour obviously more consistent with determinism than randomness.

Since determinism is in principle falsifiable, and any fortuitously constrained non-determinism is not, determinism is the scientific choice.

Since determinism is in principle falsifiable, and any fortuitously constrained non-determinism is not, determinism is the scientific choice — Kenosha Kid

Weaving out a system of axioms is not falsifiable either but that is exactly what mathematicians do all day long. And maths is often called the only pure science.

Despite what its often called, it's not science, it's art.

the question of whether the universe is "actually" deterministic is ill conceived. It makes no practical difference to our ability to make predictions. — Echarmion

No, but as we have seen in both 'free-will' threads, it makes a difference to our default positions in the face of uncertainty.

Physical causation is an interesting term. Is causation physical? Because causation doesn't actually seem to describe a physical process. It seems more like a value judgement by which we identify some part of the web of physical processes as the "cause" and another as the "effect". — Echarmion

Yes, I think that may be true (certainly if one has a grasp on some of the physics around time - which I certainly don't) I imagine it would seem very much that way. By physical causation here I just mean that some event in our physical universe can be assigned as the cause with reasonable grounds. It's justificatory rather than an holistic claim.

It's unclear to me what it means for "indeterminism to resolve to determinism at a cellular scale", except as a statement on our ability to predict outcomes. Physically, what actually happens always happens at the micro scale. The macro scale is a human construct. Not some arbitrary fantasy, of course, but still an abstraction based on our particular sensory and mental apparatus. — Echarmion

That's right. Basically we seem to be able to ignore whatever weirdness takes place at a quantum level because when it gets to a scale we actually experience it's almost all gone away even in those experiments which we can measure with high accuracy (classical physics). As such, when faced with much larger errors in, say, psychology, it seems unwarranted to me to suddenly assume this micro-scale indeterminacy is responsible rather than factors like experimental degrees of freedom, complexity etc.

So, insofar as we don't know what the source of our uncertainty is, it seems odd to invoke new mysterious mechanisms when the ones we already have explain it perfectly well. — Isaac


Could you explain what you refer to as "our uncertainty" here? I don't really follow. — Echarmion

Hopefully explained above. Just that if the cause of error in our experimental results can be explained with what we already know - complex systems dynamics, experimental degrees of freedom, hidden variables etc., and in experiments where these factors are lessened we do indeed see a lessening of error, then it seems unreasonable to invoke some other cause.

Weaving out a system of axioms is not falsifiable either but that is exactly what mathematicians do all day long. And maths is often called the only pure science. — Heiko

Falsification is a criterion of real science, i.e.the circular process of modelling, prediction and experiment.

As I've said a few times, if we ever devise a test to discern whether QM is Copenhagen-like or MWI-like that is inconsistent with the latter, I would consider fundamental determinism falsified — Kenosha Kid

Put this way, the choice is between: 1) assuming that the wheels of determinism have a little 'lash' between them (indeterminism), and 2) assuming the existence of billions of billions of billions of parallel universes out there...