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.