Quantum Indeterminacy and Libertarian free will

Relativist

Quantum Indeterminacy and Libertarian free will.

In another thread, I presented the following thought experiment:

In the actual world, you are presented with a choice between X and Y. You deliberate on the options, weighing pros &cons consistent with your background beliefs and dispositions, and you ultimately choose X (possibly influenced by some sudden impulse). Is there a possible world with an identical history to this one, so that you have exactly the same background beliefs, desires and impulses at the point at which the choice is presented - but you instead choose Y?

If such a world is not possible, then the choice is determined and Libertarian Free Will (LFW) does not exist. This should not be controversial. Libertarians believe a choice is freely willed only if the Principle of Alternative Possibilities is true.

Now consider the very real possibility that mental activity is partly influenced by quantum mechanics (it has been theorized that the energy associated with mental activity is stored at the quantum level). Where QM is involved, there is quantum indeterminacy. Quantum indeterminacy creates a truly random factor that results in alternative possibilities to a choice despite all other factors being fixed.

***edit* Most interpretations of quantum mechanics views the "measurement problem" as indicating there is true ontological indeterminacy. ***

The question for discussion: if quantum indeterminacy is the only actual source of alternative possibilities, is this sufficient to consider the choice a product of libertarian free will?

***edit** If a libertarian believes quantum indeterminacy is inadequate for LFW, despite it techincally meeting the terms of the Principle of Alternative Possibilities (PAP), then please provide a re-worded PAP, or some other means of identifying LFW.

RegularGuy

↪Relativist

It seems to me that quantum indeterminacy is a function of nature, not a function of a free agent. So no. This does not help the LFW cause.

Edit: A free agent would have to be able to consciously control quanta intentionally in order for the person to be a free “agent”.

RegularGuy

↪Relativist

On further thought, perhaps a conscious mind CAN influence quanta. However, strict reductionists would call this a function of nature. If the mind simply supervenes on the material brain, then I don’t know.

Relativist

↪Noah Te Stroete

OK, but any factor under the agent's control seems determinative, which falsifies LFW. Refer back to the thought experiment: It seems to be the case that there is such a possible world only if there is no reason for the choice.

RegularGuy

↪Relativist

Then no. I don’t see how LFW makes any sense.

Jamesk

So all we can prove here is that in a causally determined universe there are some completely random acts and so we must take into account some randomness as part of determinism. Unless I have missed the thrust of your point I will invoke Hume and say that being influenced by random forces does not support freewill or moral responsibility.

RegularGuy

↪Relativist

Furthermore, a decision or choosing is nothing like the behaviors of quanta.

Mentalusion

here's generally what quantum indeterminacy is from Wikipedia:

Quantum indeterminacy is the apparent necessary incompleteness in the description of a physical system, that has become one of the characteristics of the standard description of quantum physics.
Prior to quantum physics, it was thought that
(a) a physical system had a determinate state which uniquely determined all the values of its measurable properties, and conversely(b) the values of its measurable properties uniquely determined the state.

So, all quantum indeterminacy is is the claim that all the MEASURABLE properties don't fully map out all of the characteristics of a physical system. I take this to meant that at least one thing QM is potentially concerned with are the UNMEASURABLE values that might determine that state or system. Call the object of that concern "X". At least one possible candidate for what "X" is, is an adequately defined conceptions of LFW. Consequently, not only is LFW compatible w/ QM, it could, in fact, be precisely what QM scientists are looking for.

RegularGuy

↪Mentalusion

Are you suggesting that quanta could have LFW? I’m sure that’s not what you meant. Could you flesh out the details for the argument for LFW wrt quantum mechanics? I fail to see how the two are related.

Mentalusion

My understanding is that QM is just describing physical nature. Part of that nature according to QM is that it is indeterminate, that is, there is a degree to which it cannot be measured. It's unmeasurability is taken as constitutive of physical nature itself by QM. QM does not attempt to explain - except perhaps as conjecture - why physical nature is so indeterminate. It is primarily concerned with describing that indeterminacy. One explanation, though, for why it is indeterminate is because matter or quanta or whatever fundamental physical "stuff" there is, in some way, makes free decisions. Obviously, it probably does not do this in the same way we do at the macro-level or with the same level of complexity, or w/ regard to the same kinds of possibilities. Nevertheless, a possible explanation for indeterminacy is that quanta do make decisions about how to behave.

RegularGuy

Nevertheless, a possible explanation for indeterminacy is that quanta do make decisions about how to behave. — Mentalusion

That’s a very strange claim.

Mentalusion

↪Noah Te Stroete

meh, I think it's actually quite similar to what Leibnitz said about monads back in the day

Although, yeah, it is pretty strange

RegularGuy

↪Mentalusion

Leibnitz was strange, too.

Heiko

How much energy would we need to apply to a human being to actually determine it's indeterminacy at quantum level throughout?
My guess is "ouch..."

RegularGuy

If String Theory is true, then even quanta’s behavior is fully determined. However, String Theory is also very strange.

Terrapin Station

↪Noah Te Stroete

What I mean by free will is that I can make choices that are like rolling dice (where we assume that the dice outcome really is random), but where I'm also able to bias the roll, so that given four options, I can bias the probabilities to, say, 40%, 30%, 20%, 10%.

In my view this is a completely naturalistic phenomenon. I'm a physicalist. An identity theorist.

And I don't think that the natural mechanism would necessarily have to be quantum. Some macro phenomena could turn out to be random or probabilistic rather than deterministic.

RegularGuy

What I mean by free will is that I can make choices that are like rolling dice — Terrapin Station

Does one really do this? It seems that any deliberative choice is fully determined by brain states, and the only way choices are like rolling dice is that we don’t know the consequences of our choices until later. Or maybe I just don’t understand what you’re saying.

Terrapin Station

↪Noah Te Stroete

It seems to me like I can (and often do) make random-but-unequally-probable choices.

RegularGuy

↪Terrapin Station

Can you give an example of a random choice you’ve made today?

Terrapin Station

↪Noah Te Stroete

Sure. What program to watch from my DVR while eating lunch.

RegularGuy

↪Terrapin Station

And the program you did ultimately choose was not fully determined by your brain states? Your memory, beliefs, mood, and particular desires at the time of choosing?

Terrapin Station

↪Noah Te Stroete

Right. Phenomenally, I randomly chose it, albeit while not biasing all of the options completely equally. I do this for things I choose all the time.

RegularGuy

↪Terrapin Station

I suppose one could choose randomly. I just never do as far as I’m aware. Perhaps that’s my brain damage.

Relativist

↪Mentalusion

Interpretations of Quantum Mechanics does seek to explain the indeterminacy. I am aware of only two interpretations that are consistent with strict determinism:
1) Bohmian - which assumes there are non-local variables that determine the discrete state of the system; I don't believe this is well accepted.
2) Many Worlds - which assumes all possible measurements of the system actually exist as a branch of a meta-universe. This has more acceptance (and also vehement rejectors), but even if true - the world we find ourselves in is random (there's a copy of us in each world).

For purposes of the discussion, consider quantum indeterminacy to entail ontological indeterminacy, not just a measurement problem. This is consistent with all interpretations except Bohmian.

Relativist

What I mean by free will is that I can make choices that are like rolling dice (where we assume that the dice outcome really is random), but where I'm also able to bias the roll, so that given four options, I can bias the probabilities to, say, 40%, 30%, 20%, 10%.

In my view this is a completely naturalistic phenomenon. I'm a physicalist. An identity theorist.

And I don't think that the natural mechanism would necessarily have to be quantum. Some macro phenomena could turn out to be random or probabilistic rather than deterministic. — Terrapin Station

Does quantum indeterminacy satisfy your assumption of randomness. It is REALLY random, unlike dice throwing. Do you think this randomness is sufficient to meet the assumptions of Libertarian Free Will?

Mentalusion

↪Relativist

For purposes of the discussion, consider quantum indeterminacy to entail ontological indeterminacy, not just a measurement problem. — Relativist

OK, how does that change anything I said?

Relativist

How much energy would we need to apply to a human being to actually determine it's indeterminacy at quantum level throughout? — Heiko

Not so much. See this. Of particular relevance is footnote 41, which refers to a 1968 journal article that proposes the energy for neuronal activity is stored at the QM level - which is intrinsically indeterminate.

Relativist

↪Mentalusion

Maybe nothing, but I wanted to clarify that quantum indeterminacy is generally regarded as ontologically indeterminate. I gather you do actually accept that. Cool.

Heiko

For purposes of the discussion, consider quantum indeterminacy to entail ontological indeterminacy, not just a measurement problem. — Relativist

What do you mean by "ontological" here? "Ontological" in the sense of modern physics seems to explicitely mean to describe the things as they appear. Schroedinger's cat for example "is" alive and dead at the same time as an observer of the box cannot distinguish this. The cat was never asked....

Relativist

↪Heiko

By "ontological" - I'm referring to things as the actually ARE (as the exist), not merely what is measured.

All interpretations of QM are consistent with what is measured, but make assumptions about what exists. e.g. many Worlds Interpretation assumes these worlds actually exist, even though it is impossible to access (or measure) them.

Terrapin Station

↪Relativist

I don't think we know what is and isn't really random. But sure, maybe quantum phenomena are the key.

Quantum Indeterminacy and Libertarian free will

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