Free Will.

[pErvinalia]

What's your proof for this claim?

[JimC]

Also, according to the Wikipedia article rEv so helpfully quoted, it is also wrong. rEv just added emphasis to the wrong sentence.

Huh? Jim claimed that chaos theory refutes the concept of a deterministic universe. I quoted the bit that says that chaos theory doesn't refute the concept of a deterministic universe.

Sorry. Yes you did. I do think though that the words "small differences" are the crucial ones concerning where Jim went wrong. They concretely and expressly deny his opinion that differences will develop even when initial conditions are identical.

This is where I'm going to play the quantum card. It is simply impossible for two initial states to be absolutely identical, even if the difference occurs down at the level of the quantum foam. Chaos multiplies even the most minuscule difference exponentially, and quantum theory would provide the required tiny differences.

QED...

[pErvinalia]

Quantum indeterminacy collapses into physical determinism at macro scales.

[JimC]

Quantum indeterminacy collapses into physical determinism at macro scales.

That's true, but in the context we've been discussing, all it needs to do is provide a tiny degree of uncertainty about the physical parameters (such as position and/or momentum) of the initial state of a system.

If the system has the features required to be considered chaotic, then all that is required is that an arbitrarily small difference in initial conditions will lead to large differences as the system evolves. For perfect prediction, there needs to be perfect knowledge of the initial conditions. Quantum indeterminacy prevents such perfect knowledge...

However, in practice, in most situations, this is really not an issue. In a situation with 2 gases diffusing into each other, for example, we can make a perfectly accurate prediction of the statistical behaviour of the particles over time, even if it is intrinsically impossible to predict the position of each gas particle. Pragmatically, this is usually enough...

[pErvinalia]

Quantum indeterminacy collapses into physical determinism at macro scales.

That's true, but in the context we've been discussing, all it needs to do is provide a tiny degree of uncertainty about the physical parameters (such as position and/or momentum) of the initial state of a system.

If the system has the features required to be considered chaotic, then all that is required is that an arbitrarily small difference in initial conditions will lead to large differences as the system evolves. For perfect prediction, there needs to be perfect knowledge of the initial conditions. Quantum indeterminacy prevents such perfect knowledge...

That's actually irrelevant to the problem. Calculation/prediction is not correlated with determinacy. A deterministic system can be unpredictable or predictable.

I've avoided quantum mechanics for the last 5+ years, as it does my head in. So I did a bit of googling to try to get a fix on this issue. I was going to write a summary of what I found, but this - http://plato.stanford.edu/entries/deter ... al/#QuaMec - pretty much sums it up. It's the result (or non-result) of the Bohr-Einstein debates that took place in the early 20th century regarding the underlying nature of quantum system. Essentially, there's no experimental (or mathematical) evidence either way (and might never be due to quantum nature) to confirm whether determinism or indeterminism underlie quantum systems. There's a number of quantum theory interpretations, of which, none have been proved to describe any underlying reality. Interestingly, the most common one (well, when I last read about this) - the Copenhagen Interpretation - asserts as far as I can tell that quantum states don't really "exist". "Existence" doesn't occur until the wave function collapses, at which point determinism then applies. So in that sense, a quantum probabilistic state can't influence physical reality until it de-coheres.

In any case, randomness in physical interactions/laws doesn't help the argument for free will. Free will really implies an agency that is disconnected from what came before it. That is, essentially an ineffable soul. If you read a bit about the subject of free will you come across the bollocks of "compatibalism" - that is, free will and determinism are compatible with each other. Daniel Dennett is a proponent of this. The problem with this is that it redefines "free will" to mean something else (ability for "choices" to occur) other than what it really means in these debates (agency to choose one or the other independent of all that has gone before you in the universe).

[rainbow]

It has nothing to do with physics.
To have a deterministic universe you require an Objective Reality.

We cannot assume an Objective Reality exists since we can only observe the universe subjectively.
The only way an Objective Reality could exist is if the Universe could be observed by a Supreme Being.

[pErvinalia]

It has nothing to do with physics.
To have a deterministic universe you require an Objective Reality.

Who says there's no objective reality?

We cannot assume an Objective Reality exists since we can only observe the universe subjectively.

That's irrelevant to free will, though. Whether we have free will or not is independent of whether we are interacting with underlying really real reality, or a non really real subjective reality.

The only way an Objective Reality could exist is if the Universe could be observed by a Supreme Being.

What does "Objective Reality" have to do with observation by a "Supreme Being", whatever that is?

[tuco]

The question is: How to test for free will?

If its not possible to design test for free will, debates are just debates. Metaphysics never proved anything.

[pErvinalia]

Well some people don't view it as a metaphysical question, but I can't see how it can be anything else.

[mistermack]

As far as chaos and quantum theory go, it's not proved that identical starting conditions will produce different outcomes.
What quantum theory says is that it's NOT POSSIBLE in practice to have identical starting conditions.

You can still argue that if starting conditions were identical, you would get identical outcomes. That might be true, but it can't happen so it's irrelevant.
I think.

[laklak]

The best way to deal with these sorts of questions is to roll a fattie. It's the only way to be sure.

[mistermack]

The best way to deal with these sorts of questions is to roll a fattie. It's the only way to be sure.

Can't stop thinking about sex, can you?

[laklak]

I see it as a gift.

[Svartalf]

The question is: How to test for free will?

If its not possible to design test for free will, debates are just debates. Metaphysics never proved anything.

Actually, there is play of free will even when deterministic factors are at play.
When I am taken with the need to poop, I can decide to delay it until either I am finished with what Im doing, and sovereignly decide to give in, or I do perceive the need to be too imperious to resist anymore, and even then I could still resist and risk pooping my pants.

[JimC]

rEvolutionist wrote:

In any case, randomness in physical interactions/laws doesn't help the argument for free will. Free will really implies an agency that is disconnected from what came before it.

Generally, I agree that there is a disconnect. Although you could not have free will (without some form of spirit nonsense) in an absolutely determinist physical universe, free will is not guaranteed by a non-determinist universe that I suggest arises from a combination of chaos theory and the lack of absolute precision in starting conditions. As an aside, I do see a connection between prediction and determinism. If it is inherently impossible to fully predict the future state of a physical system, even with perfect knowledge of initial conditions (to the limit imposed by quantum uncertainty) and unlimited computational power, then the system cannot be said to be fully determined.

I have a similar view on free will as I do to consciousness (which are surely linked). Both are useful illusions, which let us act in the world as if we were free agents. Decisions made under the spell of this view of the world are likely to be fast, effective and useful to survival under the conditions that applied during most of our evolutionary history.

There have been several articles in the New Scientist over the years about measurements of brain activity which occur fractionally before the neurones involved in "conscious" decision making fire. It is implied that this is contrary to the standard view of free will; whether this is valid I'm not certain...

As far as chaos and quantum theory go, it's not proved that identical starting conditions will produce different outcomes.
What quantum theory says is that it's NOT POSSIBLE in practice to have identical starting conditions.

You can still argue that if starting conditions were identical, you would get identical outcomes. That might be true, but it can't happen so it's irrelevant.
I think.

That is certainly the way I was thinking...