Took out my first Opossum just a couple weeks ago. It wasn't a conscious choice to do so. — noAxioms

...and you did so with a car, correct? Then it's possumslaughter, and not murder...

What's the problem then? Change happens over time. Where's the problem? I made no mention of points in that.

What happened to decisions and the eventual state of no longer being able to have chosen otherwise? — noAxioms

I think the problem is, that if change happens over time, and a person can always change one's mind as time passes, then how does that state of not being able to choose otherwise ever come about?

I think that "not being able to choose" is always there, to some degree, as what is impossible. One cannot make happen what is impossible. So as time passes what is possible, and what is impossible, is always changing. That's what change is. We make our decisions based on how we understand what is possible and what is impossible, in relation to what is wanted. We always misunderstand, to some degree.

Therefore it's always possible to choose otherwise, all the time. But some things are not possible, even if we think they are, and try to make them happen. Likewise, many things which are possible we never even consider.

Thank you for your detailed reply.

1. On decoherence, chaos and “everything matters”
You’re right to insist that every physical event in principle influences the future state of the universe. But there are three separate claims mixed together here, and they need to be untangled:

Claim A: “Every decoherence event must produce a macroscopically different future.”*
This is false as a practical claim. Mathematically, you can map a micro-perturbation forward, but most microscopic differences remain confined beneath the system’s Lyapunov horizon and are washed out by dissipation and averaging. Saying “it mattered in principle” is not the same as “it produced a distinct, observable macroscopic outcome.”

Claim B: “If a quantum event didn’t cascade to macroscopic difference, then it didn’t happen.”
This is a category error. An event’s occurrence is not defined by whether it produces long-range, observable divergence in weather on Mars. Decoherence can and does happen locally without producing macroscopic differences that survive coarse-graining. To deny the event happened because it didn’t alter the weather is to adopt a peculiar, counterfactual definition of “happened” that isn’t used in physics.

Claim C: “Because chaotic systems amplify differences, microscopic quantum noise always matters.”
Chaos gives sensitivity to initial conditions, not guaranteed macroscopic divergence from every tiny perturbation within any fixed observational timescale. Some perturbations are amplified quickly; many are damped or trapped inside subsystems and never produce a new, robust classical structure. So yes, everything is part of the state functionally, but that does not imply practical, observable macroscopic branching for every microscopic event.

2. On ensemble forecasting and pragmatic unpredictability
Ensemble weather models show that small perturbations grow and forecasts diverge over days to weeks. That demonstrates sensitivity, not an omnipresent quantum-to-macroscopic channel that we can exploit or even detect in a controlled way. Ensemble perturbations used in practice are far larger than Planck-scale corrections; their convergence tells us about statistical predictability and model error, it does not prove ontic indeterminacy at the macroscale. In short: models are evidence of chaotic growth, not of routine quantum domination of weather.

3. Interpretations of quantum mechanics - collapse, MWI, Bohmian, etc.
Two helpful distinctions:

Predictive equivalence vs metaphysics.
Most mainstream interpretations (Copenhagen-style pragmatism, Everett/MWI, Bohmian/DBB, GRW-style objective collapse) make the same experimental predictions for standard quantum experiments. Where they differ is metaphysical: whether there is a literal branching reality (MWI), hidden variables (Bohmian), or real collapses (GRW/Penrose). That difference matters philosophically but not experimentally so far.

Determinism vs practical unpredictability.
MWI is best understood as deterministic at the universal wave function level (no collapse), while Bohmian mechanics is deterministic at the level of particle trajectories guided by the wave function. Both can produce the same Born probabilities for observable results. Objective collapse theories, if true, would introduce genuine stochastic events at the fundamental level. Superdeterminism attempts to recover determinism by postulating global correlations that undermine usual independence assumptions - but it’s philosophically and scientifically unattractive because it erodes the basis for experimental inference.

So: yes, many interpretations are deterministic; some are not. But the existence of multiple empirically-equivalent interpretations means the metaphysical verdict isn’t settled by current experiments.

4. Functional robustness (brains, transistors, computation)
Absolutely: brains and silicon devices exploit enormous redundancy and averaging to achieve robust classical behaviour despite quantum microphysics. That robustness is precisely why we can treat neurons as implementing computations without invoking exotic quantum effects. Inputs and boundary conditions matter: if an input to a brain were influenced by a huge amplification of a quantum event, your choices could track that influence, but that’s a contingent physical story, not a metaphysical proof of libertarian free will.

5. About “happening”, counterfactuals and responsibility
Two related points:

Happening and counterfactual dependence.
Whether an event “happened” should not be defined by whether it caused a macroscopic divergence millions of miles away. Physics generally treats events as happening if they leave local, causal traces (entanglement, records, thermodynamic irreversibility), not by whether they produce globally visible differences across light-years.

Responsibility and determinism.
Even if one accepts a deterministic physical description (whether classical or quantum-deterministic under MWI or Bohmian), that does not automatically dissolve ordinary moral responsibility. That’s the compatibilist position: responsibility depends on capacities, reasons-responsiveness, and the appropriate psychological relations, not on metaphysical indeterminism. Saying “my decision was set at the Big Bang” is metaphysically dramatic but doesn’t change whether you deliberated, had conscious intentions, and acted for your reason(s) - which are precisely the things our ethics and law respond to.

6. About “pondering” and the illusion of choice
You’re right to resist the crude conclusion that determinism makes choice an illusion. Choice is a process that unfolds over time; it can be broken into sub-choices and revisions. Whether decisions are determined or involve ontic randomness does not by itself answer whether they were genuinely yours. If you deliberated, weighed reasons, and acted from those deliberations, we rightly treat that as agency. Randomness doesn’t create agency; reasons and responsiveness do.

We shouldn’t conflate three different claims: (A) that micro events in principle influence the universal state; (B) that such influence routinely produces distinct, observable macroscopic outcomes; and (C) that metaphysical determinism therefore undermines agency. In practice, decoherence + dissipation + coarse-graining mean most quantum perturbations don’t make detectable macroscopic differences. Interpretations of quantum mechanics disagree about metaphysics but agree on predictions. And finally, even in a deterministic physical world, agency and moral responsibility can still be meaningful because they hinge on capacities, reasons, and psychological continuity, not on metaphysical indeterminism.

The pondering is not an illusion. With the possible exception of epiphenomenalism, the pondering takes place, and the decision is the result of that. Given DBB style determinism, your decision to select chocolate was set at the big bang. Not true under almost any other interpretation, but under all of them (any scientific interpretation), the chocolate decision was a function of state just prior to the pondering, which does not mean it wasn't your decision.

Yes, I know it isn't a true illusion. I said it's a "functional illusion", meaning that since the chocolate conclusion was set at the Big Bang (as you noted), no amount of pondering vanilla was going to result in it's selection, or at least as you correctly noted at the mind state just before the pondering started. Thus while we all agree pondering occurs, as I mentioned, folks disagree whether both sides of the internal argument can result in chocolate or vanilla on one hand or always chocolate on the other.

A distinction without importance since in reality there is no practical difference. My advice: choose the option that sits best with you worldview and move on (to questions that can actually make a difference here on planet Earth).

Claim A: “Every decoherence event must produce a macroscopically different future.” — Truth Seeker

High probability of that, but the claim is not there. Again, Norton's dome can result in the same state from multiple different initial states, thus falsifying that claim. It's a classical analysis, and it would be interesting to see if a similar scenario could be done in the quantum realm, such as different pairs of photons (coming from different directions, but with the same collective energy/momentum) combining into identical states of electron/positron pair.

None of what I posted about macroscopic differences is 'in principle'. It's very much in practice, and differences don't remain contained. All such events are beneath any system’s Lyapunov horizon and thus take at least that much time to show up as macroscopic differences.

Claim B: “If a quantum event didn’t cascade to macroscopic difference, then it didn’t happen.”

That claim presumes the principle of counterfactual definiteness (PCD) is false, which it is in almost every interpretation. But given that principle, the claim is false. I said as much in prior posts. It cascading into a macroscopic difference is way different than the difference being observed, which is of course impossible. Nobody can observe both the live and dead cat.

So the quantum event doesn't technically alter the weather since that wording implies there was one base weather that would have otherwise been. No, each event is a critical part of the cause of any sufficiently distant weather state, a very different claim than 'alters'.

Claim C: “Because chaotic systems amplify differences, microscopic quantum noise always matters.”

I think I agree with this one, with 'always' being replaced by 'always to a lot of decimal places'.

Some perturbations are amplified quickly; many are damped or trapped inside subsystems and never produce a new, robust classical structure.

Sort of. Imagine something tiny annihilating into radiation that ends up in deep space, never hitting anything. Also the tiny thing, had it not died like that, would also never have interacted with anything else. That's an example of that 'trapped', but it's also an example of an event that never happened in the absence of PCD.

2. On ensemble forecasting and pragmatic unpredictability
Ensemble weather models show that small perturbations grow and forecasts diverge over days to weeks. That demonstrates sensitivity, not an omnipresent quantum-to-macroscopic channel that we can exploit or even detect in a controlled way. — Truth Seeker

Correct. None of those models run at quantum scale precision. The input data is more like data points that are kilometers apart, not nanometers apart.

More precision would be nice, but data gathering is limited and small scale differences (molecular?) make no significant difference in just the 10 days these models are good for.

Most mainstream interpretations (Copenhagen-style pragmatism, Everett/MWI, Bohmian/DBB, GRW-style objective collapse) make the same experimental predictions for standard quantum experiments.

If there are any interpretations that make different predictions, then either the interpretation is wrong, or QM is.

Where they differ is metaphysical: whether there is a literal branching reality (MWI), hidden variables (Bohmian), or real collapses (GRW/Penrose). That difference matters philosophically but not experimentally so far.

Just so. This is why when you take a graduate level course in quantum mechanics, they might spend a day on interpretations, but it being philosophy, it has no scientific value. The course teaches theory, not philosophy. The determinism debate is also philosophy.

The bit I said about some events never happening? That's philosophy. Empirically, whether it happened or not is indistinguishable, so it isn't part of theory.

Determinism vs practical unpredictability.
MWI is best understood as deterministic at the universal wave function level (no collapse), while Bohmian mechanics is deterministic at the level of particle trajectories guided by the wave function.

Something like that. The wave function has multiple solutions, so DBB needs more than just that to guide particles to one outcome.

Responsibility and determinism.
Even if one accepts a deterministic physical description (whether classical or quantum-deterministic under MWI or Bohmian) — Truth Seeker

MWI is deterministic, but not classical. There's no 'you' with a meaningful identity in that view. Responsibility is a classical concept and requires a pragmatic classical view of identity, regardless of interpretations of choice.
This is not contradictory. The pragmatic part of me believes all sorts of things that the rational side of me knows is wrong. I would not be fit were the case to be otherwise. Hence my being responsible for my choices.

That’s the compatibilist position: responsibility depends on capacities, reasons-responsiveness, and the appropriate psychological relations, not on metaphysical indeterminism.

I would have said that it depends on the entity being held responsible being the same entity making the choice. Determinism just doesn't factor at all into that definition.
Compatibilism is a bit different. It asserts free will in the face of determinism. I don't, but it depends on one's definition of free will. I don't think I have free will as typically defined, but that in no way relieves me of moral responsibility since I'm still making my own choices. So I don't label myself a compatibilist.

Saying “my decision was set at the Big Bang” is metaphysically dramatic but doesn’t change whether you deliberated, had conscious intentions, and acted for your reason(s) - which are precisely the things our ethics and law respond to.

Yes. My opinion is that my decision was not at all set at the big bang, but that just means I don't buy into DBB, probably the only interpretation that suggests that.

6. About “pondering” and the illusion of choice
You’re right to resist the crude conclusion that determinism makes choice an illusion. Choice is a process that unfolds over time; it can be broken into sub-choices and revisions. Whether decisions are determined or involve ontic randomness does not by itself answer whether they were genuinely yours. If you deliberated, weighed reasons, and acted from those deliberations, we rightly treat that as agency. Randomness doesn’t create agency; reasons and responsiveness do.

We seem to be on the same page.

In practice, decoherence + dissipation + coarse-graining mean most quantum perturbations don’t make detectable macroscopic differences.

I'd even argue that none of them make detectable macroscopic differences. I mean, I measure an atom decay. Great, but I don't have a not-decay state to compare it with, so there's no 'difference'. I can imagine that other state since it is pretty simple, but I cannot imagine the evolution of that real and imagined state into a future state of a planet a year hence.

Yes, I know it isn't a true illusion. I said it's a "functional illusion", meaning that since the chocolate conclusion was set at the Big Bang (as you noted) — LuckyR

See just above, where only DBB suggests that chocolate choice was set at the big bang. DBB should stand for 'Da Big Bang'. Chicago folks would like that.

Thus while we all agree pondering occurs, as I mentioned, folks disagree whether both sides of the internal argument can result in chocolate or vanilla on one hand or always chocolate on the other.

I think it's all in how you frame the telling of the story. Proponents of 'vanilla being possibly chosen' would frame the story in such terms. Yea, you could have picked that, but you didn't, didja? If you had, you'd still ponder if you could have chosen chocolate.

A distinction without importance since in reality there is no practical difference.

Yes, and deal with the consequences. It's pretty easy to falsify the 'not responsible' stance since if one wasn't to be held responsible, different choices would be made. That means responsibility serves a purpose regardless of your stance.

it's possumslaughter — ProtagoranSocratist

I'd call it marsupicide

I think the problem is, that if change happens over time, and a person can always change one's mind as time passes, then how does that state of not being able to choose otherwise ever come about? — Metaphysician Undercover

Eventually one much act on the choice, irrevocably. You debate committing murder, but once the trigger is pulled, there's no doing otherwise. I suppose if you choose not to do it, the option remains open for quite some time.

The vanilla/chocolate debate at the ice cream shop. Exactly how late can one change one's mind before it's too late? We played a game like that with my 1 year old at a restaurant. He was feeding himself stuff from his plate with a spoon. He really like crab leg bits thrown on his plate and would eat those first. Game was to see how far we could get him to choose to eat something else, and still bail out because a crab bit was presented. I won the game when I caused an abort with the spoon already fully in his mouth. Imagine the cheering at the table, causing weird looks from others.
We're easily entertained over here.

I think that "not being able to choose" is always there, to some degree, as what is impossible. One cannot make happen what is impossible.

Yes, that's physics getting in the way of free will. I cannot get out of this jail because physics compels me to stay here. Nobody can do everything they want to.

Therefore it's always possible to choose otherwise, all the time.

Yes, that's what it means for there to be a choice. I'd argue that such choice is not always possible. Sometimes only one path is open. Sometimes not even that. Vanilla or chocolate? Well, there's a power outage at the softserve shop, so as Gene Wilder put it: You get Nothing.

Yes, that's physics getting in the way of free will. I cannot get out of this jail because physics compels me to stay here. Nobody can do everything they want to. — noAxioms

or in other words, you're in a state of relative inertia: you know getting out would be hard, you know the charge isn't that severe (and don't want the extra punishment), so you sit there until someone says you can go. It's mild fear mixed with resignation.

However, in the other scenario among many, energy and angst compel you to get out because you see an opening, which is arguably still not anything you have control over...

Eventually one much act on the choice, irrevocably. You debate committing murder, but once the trigger is pulled, there's no doing otherwise. I suppose if you choose not to do it, the option remains open for quite some time. — noAxioms

It's a lot more precise than how you make it out. Imagine, the assassin sights the target. The window of opportunity is short, and the decision must be made quickly because the target moves on. So as much as the option remains, even after deciding not to pull the trigger, it would all have to be recalculated, and in reality would be a different option.

Consider firing a rocket to the moon. Everything is calculated to the exact liftoff time, and there's a small window. If there is a problem and the window is missed, everything has to be refigured. In general, and in words, it's refigured as the same option, "firing a rocket to the moon", but since it's refigured under different circumstances, it's not really the same option, just the same type of action under different conditions.

The vanilla/chocolate debate at the ice cream shop. Exactly how late can one change one's mind before it's too late? We played a game like that with my 1 year old at a restaurant. He was feeding himself stuff from his plate with a spoon. He really like crab leg bits thrown on his plate and would eat those first. Game was to see how far we could get him to choose to eat something else, and still bail out because a crab bit was presented. I won the game when I caused an abort with the spoon already fully in his mouth. Imagine the cheering at the table, causing weird looks from others.
We're easily entertained over here. — noAxioms

I think there is reverse psychology which comes into play here. So long as one does not pull the trigger, we can always consider doing so at a later time. But once the trigger is pulled that cannot be reversed. So, the psychology is that it is universally better not to act unless one is quite certain of success. The rocket cannot be retrieved after it's fired, so be sure of success before firing. However, if it is not fired, there will be many opportunities of the same type, therefore hold on until you're sure.

Your son got the punishment of reverse psychology. You pushed him toward failure, by inciting him to pull the trigger on something other than the best situation. Then he was embarrassed by jumping the gun, rather than patiently waiting, having to spit it out. That's why patience is a virtue.

Yes, that's what it means for there to be a choice. I'd argue that such choice is not always possible. Sometimes only one path is open. Sometimes not even that. Vanilla or chocolate? Well, there's a power outage at the softserve shop, so as Gene Wilder put it: You get Nothing. — noAxioms

How could there ever be only one path open? The future is always full of possibilities. And by being patient and not pulling the trigger we allow the possibilities to persist. But even falsely pulling the trigger only results in some kind of embarrassment. So if you pull the trigger and you're on the road to the softserve shop when the power goes out, you can turn around and go somewhere else. And even after the assassin fires the shot, he could fire another and another.

I believe the lesson is, that when you make the act, you put things in motion which inevitably restrict your future acts, unless your act is designed to increase your freedom, and it is successful. So the first principle is that nonaction maintains freedom. The second principle is that you might act in a way which would increase your freedom, but you need to be certain, because failure will backfire and lessen it.

Thank you for the thoughtful engagement - I think we’re converging on several points while framing them differently.

On Claim A, I accept that Norton’s Dome demonstrates classical indeterminism under non-Lipschitz conditions, though it’s a purely mathematical curiosity. In any physically realizable system governed by continuous differentiable dynamics, each decoherence event still alters the global quantum state. Even if that alteration remains thermodynamically undetectable within a local Lyapunov horizon, it nevertheless yields a distinct universal configuration in principle. My claim concerns this ontological divergence, not its empirical detectability.

On Claim B, you’re right that the assertion depends on whether one accepts counterfactual definiteness. I was speaking from an Everett-style, decoherence-based ontology where every event contributes to a definite branch of the universal wave function. Under that framework, an event that leaves no macroscopic trace still differentiates the overall state of the universe. The difference need not be observable to be real.

For Claim C, I’d refine “always matters” as follows: every quantum perturbation modifies the total wave function, but only some of those perturbations are amplified within our causal region into new classical structures. Others disperse or remain dynamically isolated, but they still shape the global state. “Trapped” and “amplified” are perspectival distinctions within one continuous evolution.

On determinism and responsibility, I think we share the pragmatic view. Determinism doesn’t abolish agency; it merely redefines it as a complex causal process rather than an uncaused power. Responsibility survives as a social and ethical convention that regulates behaviour within the deterministic flow. To borrow my own GENE model language, deliberation and choice are emergent computations of Genes, Environments, Nutrients, and Experiences - not exemptions from causality but expressions of it.

So when I speak of “choice” or “agency,” I mean the real-time process of deliberation that precedes action, not a metaphysical ability to have done otherwise. The phenomenology of choice remains intact, even if the universe’s total state never could have evolved differently.

On Claim B ... I was speaking from an Everett-style, decoherence-based ontology where every event contributes to a definite branch of the universal wave function. Under that framework, an event that leaves no macroscopic trace still differentiates the overall state of the universe. — Truth Seeker

Everett interpretation does not hold to CFD, so unmeasured events effectively are not part of any specific worlds (they're not 'real': scientific definition). This is all part of the recent proof that the universe is not locally real. It can be local or real (or neither), but not both. Everett's is local. CFD is an assertion of real states, independent of measurement.

For Claim C, I’d refine “always matters” as follows: every quantum perturbation modifies the total wave function, but only some of those perturbations are amplified within our causal region into new classical structures.

We apparently are not going to agree on this point.

The phenomenology of choice remains intact, even if the universe’s total state never could have evolved differently.

We agree on the responsibility point. Of note: Under Everett again, the universe can and does evolve in all possible outcomes, which includes choosing differently, not choosing at all, and of course not even existing to choose.

So as much as the option remains, even after deciding not to pull the trigger, it would all have to be recalculated, and in reality would be a different option. — Metaphysician Undercover

Sure, one can spin a drawn out choice (to go to the moon, good example) as a series of more immediate choices that have temporal windows. The choice ends when there's somebody on the moon, at which point it's hard to change your mind about doing so anymore.

So, the psychology is that it is universally better not to act unless one is quite certain of success.

That works in some situations, but a not in a fair percentage of them. Such uncertainty prevents some people from ever getting married. Sometimes this is a good thing, but often not. Don't choose poorly, but also don't reject good choices for fear of lack of 'success'.
War is another example where that psychology is a losing one. Risk taking is part of how things are best done.

Your son got the punishment of reverse psychology.

He did? He got crab legs and loved it. He also liked the other food he was eating, so at no point was he 'punished'.

Then he was embarrassed by jumping the gun

He was 1, with no concept of embarassment yet. He was unaware of a game being played in his court. He never spit anything out. That would have been even a better score than spoon-abort, already in, but not already 'unloaded'.

How could there ever be only one path open?

Since I'm quoting movies, I remember Gandalf saying "now there is but one choice" once the entrance to Moria collapsed after they had entered. Go forth into the mine was the only option remaining. They hadn't the resources to dig their way out.

I believe the lesson is, that when you make the act, you put things in motion which inevitably restrict your future acts, unless your act is designed to increase your freedom, and it is successful.

Similar to a game of Chess or Reversi. Any move restricts possible future positions to those which follow from the new current state. In Reversi in particular, playing to maximize your freedom and minimize the opponent's freedom is definitely a winning strategy. Took me 8 years to figure that out.

So the first principle is that nonaction maintains freedom.

Not always, and not even particularly often. Not looking for food definitely curtails eventual freedom.

However, in the other scenario among many, energy and angst compel you to get out because you see an opening, which is arguably still not anything you have control over... — ProtagoranSocratist

You many not have too much control over the appearance of opportunities to escape jail, but if one presents itself, you do have control to choose to act or not on it. It would also be foolish not to consider the positive and negative consequences of the various options, but some choice come fast enough that such rational weighing of options is not, well, an option.

That works in some situations, but a not in a fair percentage of them. Such uncertainty prevents some people from ever getting married. Sometimes this is a good thing, but often not. Don't choose poorly, but also don't reject good choices for fear of lack of 'success'.
War is another example where that psychology is a losing one. Risk taking is part of how things are best done. — noAxioms

Look what you are saying. It can just be turned around. Not getting married was the mistaken choice which shouldn't have been made. Rejecting good choices is making a poor choice. So it's just a matter of what descriptive words are used.

Risk is never the best option. It is often unavoidable, but then the best option is the one which reduces the risk. See it's just a matter of wording. And the reason why it's confusing is because we are leaving out a key aspect. Success is in relation to a goal. So "unavoidable" is determined in relation to the goal. Once we frame things as being in relation to a goal, the whole perspective is variable, depending on the goal.

He was 1, with no concept of embarassment yet. — noAxioms

A child does not need to understand the concept of embarrassment, to be embarrassed. "Cheering at the table" indicates that he was most likely embarrassed, even at 1.

Not always, and not even particularly often. Not looking for food definitely curtails eventual freedom. — noAxioms

I don't agree with this. "Looking for food" implies a restriction that the person is looking for something which is known to be food. This restricts the person from eating all sorts of things which may actually be good food, yet not known to be "food" to the person.

The point being that action requires choice, and choice restricts the person's freedom to select all the other possibilities. If a hamburger is the only thing the person knows to be food, then "looking for food" is a significant restriction.

Look back at the moon example. "Going to the moon" required all those choices, and each one excluded all the other possibilities. Therefore there was a whole lot of other things which could have been done in that time, with those resources, but "going to the moon" was the chosen goal, and this negated all those other possibilities.

Thank you for the thoughtful clarification. I think our main divergence lies in how we treat ontic status within the Everett framework.

You’re right that Everett dispenses with counterfactual definiteness: only the total wave function is “real,” while definite outcomes are branch-relative. However, if every decoherence event differentiates the universal state vector, then by definition, each “unmeasured” quantum fluctuation still contributes to the branching structure of the multiverse. The fact that we only observe a subset of classical branches doesn’t mean the rest lack existence; it only means they are decohered beyond causal contact with us.

So when I say “an event that leaves no macroscopic trace still differentiates the overall state,” I mean that decoherence is ontologically generative - the universe’s global wave function encodes every microscopic difference, even those never amplified to our classical level. From that global perspective, nothing “fails to happen”; it merely fails to be observable within our branch.

As for responsibility, I agree that phenomenology remains intact. Even if the total state-space evolves deterministically, subjective deliberation and outcome differentiation are still structurally real within each branch - enough to preserve the experiential grammar of choice, if not libertarian freedom.

You’re right that Everett dispenses with counterfactual definiteness: only the total wave function is “real,” while definite outcomes are branch-relative. However, if every decoherence event differentiates the universal state vector, then by definition, each “unmeasured” quantum fluctuation still contributes to the branching structure of the multiverse. — Truth Seeker

The terminology grates with me, but more or less I agree. The universal state vector cannot differentiate since there is but only one of them, so it evolves over time, just like the universal wave function. It doesn't collapse, which I think would constitute 'differentiation'.

The fact that we only observe a subset of classical branches doesn’t mean the rest lack existence

Everett does not suggest separate 'branches' that have any kind of defined state. Such would be a counterfactual. So yea, Everett says that the universal wave function 'exists', period. It's a realist position, and it is that realism that is my primary beef with the view since it doesn't seem justified.

So when I say “an event that leaves no macroscopic trace still differentiates the overall state,” I mean that decoherence is ontologically generative - the universe’s global wave function encodes every microscopic difference, even those never amplified to our classical level.

Fine, but the only ones unamplified are the ones permanently in superposition relative to some classical state, such as the dead/live cat in a box never opened (said classical state).

From that global perspective, nothing “fails to happen”; it merely fails to be observable within our branch. — Truth Seeker

Careful. With the exception of Wigner interpretation (a solipsistic one), nothing in quantum mechanics is observer dependent. Observation plays no special role.

As for responsibility, I agree that phenomenology remains intact. Even if the total state-space evolves deterministically, subjective deliberation and outcome differentiation are still structurally real within each branch - enough to preserve the experiential grammar of choice, if not libertarian freedom.[/quote]
Agree with that, and even more, since your statement seems confined to MWI assumptions, but the conclusion is interpretation independent.
As for my opinion of Libertarian free will, that's just a term describing external agency, with no demonstration of any greater freedom than internal agency. Coming down with Rabies is an example of Libertarian free will. The agency is suddenly something other than yours, and Rabies (the external agent) now has the free will instead of you, and it compels you to bite people, and then Rabies becomes responsible for those assaults, not you.

Look what you are saying. It can just be turned around. Not getting married was the mistaken choice which shouldn't have been made. — Metaphysician Undercover

Getting married is like pulling the trigger. One can put off that choice indefinitely, but once done, it's done.
I used it as a counter for your assertion of 'certainty of success', and 'minimize risk'. Getting married is a risk (something you assert to never be the best option), even ones that seem a very good match. Not getting married is usually not the best option. Sure, it is for some people. I have 3 kids, and only one marriage is expected, thus countering my 'usually' assertion.

The point being that action requires choice, and choice restricts the person's freedom to select all the other possibilities. — Metaphysician Undercover

One never had freedom to select multiple options. Sure, you can have both vanilla and chocolate, but that's just a single third option. There's no having cake and eating it, so to speak. You have choice because you can select any valid option, but you can't choose X and also not X.

Somehow I'm guessing you meant something else by that comment, but I cannot figure out what else it might mean.

If a hamburger is the only thing the person knows to be food, then "looking for food" is a significant restriction.

OK, but I don't know how this became a discussion about ignorance of what is food. The comment was in response to your assertion of "the first principle is that nonaction maintains freedom", and my example of nonaction (and not ignorance) will cause among other things starvation, which will likely curtail freedom.

Getting married is like pulling the trigger. One can put off that choice indefinitely, but once done, it's done.
I used it as a counter for your assertion of 'certainty of success', and 'minimize risk'. Getting married is a risk (something you assert to never be the best option), even ones that seem a very good match. Not getting married is usually not the best option. Sure, it is for some people. I have 3 kids, and only one marriage is expected, thus countering my 'usually' assertion. — noAxioms

I think this is a false example. The option is usually whether or not to marry a specific person, not whether or not to get married in general. And, if you're not certain about the person, you're probably not in love, and you should not go ahead at that time. And if the question is whether or not to get married in general, you should not go ahead with that, until you are certain that it is the right thing.

The difference between the way you and I are looking at this, is that you are making some kind of 'objective' statement "getting married is a risk", and from that you are saying that risk is good. But from that 'objective' perspective, every choice is a risk, so of course risk must be good or else all choices would be bad. But that's not what I am talking about. I am talking about looking from the perspective of the person making the choice. And from that perspective, if the act is risky it's better for the person to wait until they have more confidence. Often the stakes are very low, and risk is simply not taken into consideration. But as the stakes get higher, considering the risk gets more and more important.

One never had freedom to select multiple options. Sure, you can have both vanilla and chocolate, but that's just a single third option. There's no having cake and eating it, so to speak. You have choice because you can select any valid option, but you can't choose X and also not X. — noAxioms

Sorry, I didn't make myself clear. I should have said freedom to select from all the other possibilities. So for example if there is twenty options, then the person has the freedom to select from twenty options. However, once the choice is made you restrict your freedom to select the other nineteen. That's what I meant, making a choice restricts your freedom. If you have the freedom to choose X or not X, then choosing X restricts your freedom to choose not X. Making a choice always restricts one's freedom.

OK, but I don't know how this became a discussion about ignorance of what is food. The comment was in response to your assertion of "the first principle is that nonaction maintains freedom", and my example of nonaction (and not ignorance) will cause among other things starvation, which will likely curtail freedom. — noAxioms

Your conclusion is based on the assumption that "starvation will likely curtail freedom". Those who believe that being chained to the body is a restriction to the soul would argue otherwise. So that is just a reflection of your metaphysical preference. My principle, that non-action maintains freedom is based in the logic explained above.

Thank you for your thoughtful and detailed reply. I appreciate your clarifications - especially on terminology.

When I said the universal state vector differentiates, I didn’t mean that it “splits” or collapses in any literal sense. I agree that the universal wave function evolves unitarily. What I meant is that decoherence continuously factorizes the total state into dynamically autonomous subspaces. The evolution is singular, but its structure becomes increasingly partitioned as interference terms vanish. In that descriptive sense, decoherence is ontologically generative - it produces new relational structure within the universal state, even if not new “worlds” as discrete entities.

You’re right that Everett himself didn’t speak of sharply defined “branches,” and I share your caution about reifying them. Still, decoherence does create stable quasi-classical sectors whose internal histories no longer interfere. Calling them “branches” is shorthand for these dynamically independent histories. So when I said that “an event that leaves no macroscopic trace still differentiates the overall state,” I meant that every quantum fluctuation alters the total wave function’s structure, even if those alterations remain forever unamplified from our classical perspective.

I also agree that quantum mechanics is not observer-dependent in the Wigner sense - nothing special happens because a conscious agent looks. My use of “observer” was relational, not Cartesian: any subsystem that records or correlates information functions as an “observer” relative to another. Within that relational framework, phenomenological perspectives arise naturally from entanglement structure, not metaphysical privilege.

Regarding freedom and responsibility: yes, phenomenology remains intact. Even if the total evolution is deterministic, each branch still contains agents whose deliberative architectures causally mediate outcomes within that branch. That structure grounds a compatibilist sense of agency: one can be determined and yet meaningfully responsible insofar as choices flow from one’s own evaluative processes. Libertarian freedom, by contrast, would require causal independence from one’s own nature - an incoherent notion. In your rabies analogy, the external pathogen literally overrides the person’s cognitive structure, which is why we no longer ascribe responsibility. The contrast actually illustrates compatibilism rather than libertarianism.

Stepping back, the parallel between branching and agency seems telling: both involve emergent autonomy within an underlying deterministic totality. The global state’s evolution may be seamless, yet locally it yields distinct, causally closed structures - worlds in one case, deliberating agents in the other. In both, the differentiation is real enough to sustain the lived grammar of choice, even if metaphysical freedom never enters the picture.

In my own framework - the GENE Causal Self Model - I interpret such autonomy through the interplay of Genes, Environments, Nutrients, and Experiences. Each agent’s decisions are determined by the evolving configuration of these factors, yet within that causal web, reflective self-organization still emerges. Much like decoherent branches of the wave function, selves are dynamically distinct yet law-governed substructures of a single evolving whole.

What I meant is that decoherence continuously factorizes the total state into dynamically autonomous subspaces. — Truth Seeker

Careful. It factorizes the measured state into dynamically autonomous subspaces. That means that only the systems that have measured the decohered state become entangled with it, thus becoming 'factorized' along with it. There's no universe with a dead cat in it and another with a live one. There's just the unopened box and (relative to the lab) a cat in superposition of these states. The box prevents the 'split' from decohering any further.

This is a hypothetical example. Preventing any measurement like that is essentially impossible. Sure, they've done it for barely visible objects under conditions that would kill any lifeform, and only for nanoseconds, but Schrodinger's box has actually been done. They used a tuning fork instead of a cat.

In that descriptive sense, decoherence is ontologically generative - it produces new relational structure within the universal state, even if not new “worlds” as discrete entities. — Truth Seeker

Yes, This is closer to my relational preference in interpretations. I use a relational definition of ontology, as opposed to a realist one like MWI does.

You’re right that Everett himself didn’t speak of sharply defined “branches,”

Yea, it was DeWitt who first did that, and then backed off somewhat from that description.

My use of “observer” was relational, not Cartesian

Fine. Just making sure. I tend to use the term 'measurement' instead of 'observation', but even that term has overtones of say intent. 'Interaction'?

Within that relational framework, phenomenological perspectives arise naturally from entanglement structure, not metaphysical privilege.

There are so many that I consider to be competent thinkers that presume that metaphysical privilege.

Libertarian freedom, by contrast, would require causal independence from one’s own nature — Truth Seeker

I wouldn't say that since 'one's own nature' becomes this 2nd metaphysical causal process, and thus not intedependence of one's own nature. Independence of one's physical nature perhaps, but is there even a physical nature if that kind of thing is how it all works?

- an incoherent notion. In your rabies analogy, the external pathogen literally overrides the person’s cognitive structure, which is why we no longer ascribe responsibility.

Isn't that exactly what the dualists suggest is going on? Of course, a dualist with rabies would have the physical effected, and somehow the mental component also affected, at least rendered less efficacious. Tri-ism? Three agents (physical, mental, and pathogen) all fighting for control.

I actually do report a form of it. I am occasionally afflicted with a form of epiphenomenalism where I am awake but cut off from most physical causality. I wake up from this condition, and only with an extreme mental effort can I push through my will an move something (preferably turn my head). It's called sleep paralysis, and the short of it is that your motor functions turn off when you sleep. If this mechanism is faulty, you sleepwalk. If it fails to turn on the juice when you wake up, it's sleep paralysis. I guess I don't have to worry too much about ever sleep walking.

Stepping back, the parallel between branching and agency seems telling: both involve emergent autonomy within an underlying deterministic totality. The global state’s evolution may be seamless, yet locally it yields distinct, causally closed structures - worlds in one case, deliberating agents in the other.

Agree up to here.

In both, the differentiation is real enough to sustain the lived grammar of choice, even if metaphysical freedom never enters the picture.

I don't think human choice has anything to do with differentiation since under any other interpretation where there isn't the kind of differentiation you get under MWI, the exact same choices and responsibility results. The only difference is that there are not other worlds split of sufficiently long ago that those tiny difference have grown into macroscopic difference large enough to cause different choices to be made, and my choice and responsibility has nothing to do with what those other versions are choosing.

I think this is a false example. The option is usually whether or not to marry a specific person, not whether or not to get married in general. — Metaphysician Undercover

I'm not talking about a choice to not get married. I'm talking about making a choice to commit to marriage now (propose, or accept a proposal), coupled with the subsequent actual getting married, which is the trigger being pulled: can't hypothetically undo that. Doing so would be presumably to one person.
Deciding to get married in general (with perhaps no specific prospect currently in mind) is not like pulling the trigger since one can always change one's mind about such a decision.

you should not go ahead with that, until you are certain that it is the right thing.

Few, arguably none, are ever certain of it being the correct choice. Plenty of people have attested to be certain about it, only to regret the decision later on. I'm lucky. Married over 40 years now. All my siblings are on spouse #2. The one that waited the longest to be 'most certain' ended in cheating (both parties) and divorce.

The difference between the way you and I are looking at this, is that you are making some kind of 'objective' statement "getting married is a risk", and from that you are saying that risk is good.

There's overtones of 'marriage is good' there, which I don't agree is always true. But each statement in isolation, yes I'm saying that. I have better examples of 'risk is good'. Marriage is my example of a decision of a trigger pull, something you can't undo.

I am talking about looking from the perspective of the person making the choice. And from that perspective, if the act is risky it's better for the person to wait until they have more confidence.

Disagree, for reasons and examples I've already posted. There are times when risk is high, but would likely get higher with time, and so confidence is likely to drop if you wait.
Take saving people from a burning building. You can risk your life and charge in there and grab the baby, or you can wait until the fire trucks get the fire more under control so your safety is more assured. That's a hard decision, and there are cases where each option is the best one.

So for example if there is twenty options, then the person has the freedom to select from twenty options.

Great. Agree. There are those that say that 19 of those options are not available for selection because it is the 20th you want, even if the other 19 are close contenders.

However, once the choice is made you restrict your freedom to select the other nineteen.

Under a pull-trigger sort of situation, yes. In other cases, one can change one's mind. We've been getting into the nitty-gritty about this latter case: "Was a decision really made if the option to change your mind is still open?".
The former restricts one's freedom. The latter does as well, but not nearly as much.

If you have the freedom to choose X or not X, then choosing X restricts your freedom to choose not X. Making a choice always restricts one's freedom.

Sometimes, per the above.

Anyway, I stand more clarified about your statement of making a choice curtailing freedom.

Thank you for your detailed reply. I think we’re largely aligned, though we diverge on a few interpretive nuances.

On factorization, I accept your refinement: decoherence doesn’t magically bifurcate the universal state into sealed compartments but rather entangles subsystems such that coherence between them becomes practically lost. When I said “continuously factorizes the total state,” I meant this relational entanglement structure - the effective tensor-product decomposition that yields dynamically autonomous components relative to the measurement context. So yes, the split is local and conditional, not global. I like your phrasing that “only the systems that have measured the decohered state become entangled with it.” That’s a good corrective to the loose Everettian imagery.

I share your relational preference over full-blown realism. My “ontologically generative” phrasing was intended in that same spirit: the ontology is not a collection of separate universes but a web of ever-evolving relational configurations. The structure of relations changes - new entanglement correlations come into being - even though the global amplitude distribution remains one evolving unity. So perhaps “structurally generative” would be the better expression.

Regarding “observer” versus “interaction,” I agree completely. I used “observer” phenomenologically, but “interaction” avoids the mentalistic overtones. I’m wary of language that suggests intent or consciousness as a special causal category; it risks re-smuggling the old metaphysical privilege that quantum theory works so hard to dissolve.

On free will, I think we converge on compatibilism but may use slightly different vocabularies. I take your point that “one’s own nature” could itself be construed as a second metaphysical causal chain, but I meant it more modestly: the organism’s integrated causal structure - its neural and psychological architecture - as distinct from an external intruder like the rabies virus. The point is not that one becomes “independent” of causality, but that causal efficacy remains internal to the system’s evaluative dynamics. That’s why the rabies example marks the boundary between responsibility and compulsion. Dualists, as you say, would complicate that further, perhaps imagining the pathogen interfering with both the physical and the mental “tracks,” but I see that as multiplying mysteries rather than explaining anything.

Your description of sleep paralysis is fascinating - it’s a vivid phenomenological example of partial causal decoupling: consciousness active, motor output suppressed. From a naturalistic angle, it actually illustrates how finely tuned the causal layers of agency are: when one channel is interrupted, agency becomes experiential but not performative. It’s a transient epiphenomenal pocket, not a metaphysical clue, but I can see why it feels uncanny.

As for your final point - that human choice doesn’t depend on branching - I fully agree. The experiential grammar of choice would be the same in any interpretation, whether Everettian, Bohmian, or GRW. My comparison between branching and agency was metaphorical: both involve local differentiation within a globally deterministic process. The analogy isn’t meant to make agency depend on branching, only to highlight the structural parallel between emergent autonomy in physics and in psychology.

In that sense, I see compatibilist freedom and relational quantum ontology as reflections of the same deeper pattern: causal closure at the global level, emergent quasi-autonomy at the local. In my GENE Causal Self Model, those quasi-autonomous patterns are constituted by the interaction of Genes, Environments, Nutrients, and Experiences - a biological analogue to decoherence’s relational structure. Both describe complex systems that remain causally determined yet exhibit self-organizing agency through internal feedback loops. Determinism and autonomy, far from being opposites, are two perspectives on the same relational process.

Disagree, for reasons and examples I've already posted. There are times when risk is high, but would likely get higher with time, and so confidence is likely to drop if you wait.
Take saving people from a burning building. You can risk your life and charge in there and grab the baby, or you can wait until the fire trucks get the fire more under control so your safety is more assured. That's a hard decision, and there are cases where each option is the best one. — noAxioms

I admit, I could never frame "risk" with a definition which would make it universally bad. But in thinking about it I see that there is quite a number of different ways to relate to risk. There is risk of failure. There is risk that even with success in obtaining the goal, it wasn't the best goal. There is also risk that proceeding toward one goal will produce failure relative to another. So many different types of risk.