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How physicists handle the idea of Free Will?

by fbs7
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madness
#91
Apr28-12, 07:46 AM
P: 611
Quote Quote by pftest View Post
When you say "C is determined by the physical" do you mean "C is physical"? In that case, the causal powers of C are identical to the causal powers of the physical, and it is not an epiphenomenon.

If you do not mean that C is physical, then i dont understand how the physical can influence C, but C cannot influence the physical. Or going back to the ball metaphor: how can a ball can be kicked without it touching the thing that is kicking it?
I mean that in our universe, every identical physical setup will lead to an identical instantiation of consciousness. In philosophical jargon, this means that consciousness naturally supervenes on the physical. However, since it is conceivable that we could have lived in a universe in which these same physical processes lead to a different conscious experience (e.g. we see red as blue and blue as red), we see that consciousness and physical processes are not logically identical.
Ferris_bg
#92
Apr28-12, 08:34 AM
P: 88
That sounds like the Zombie argument from Chalmers, but I don't like it and to be more precise, the word "conceive" in it.
madness
#93
Apr28-12, 09:50 AM
P: 611
Quote Quote by Ferris_bg View Post
That sounds like the Zombie argument from Chalmers, but I don't like it and to be more precise, the word "conceive" in it.
Well unfortunately, the arguments for physicalism (materialism) come from the same notion of supervenience, which is based on "possible worlds" or "conceivable worlds". It's not something you can get around if you are looking at philosophical debates of this kind.
pftest
#94
Apr29-12, 03:39 AM
P: 271
Quote Quote by madness View Post
I mean that in our universe, every identical physical setup will lead to an identical instantiation of consciousness. In philosophical jargon, this means that consciousness naturally supervenes on the physical. However, since it is conceivable that we could have lived in a universe in which these same physical processes lead to a different conscious experience (e.g. we see red as blue and blue as red), we see that consciousness and physical processes are not logically identical.
About the supervenience: isnt that how all physical things work? If two riverbeds have an identical setup, the water will flow through them identically. If two planets are identical, the spacetime will be distorted identically. If two computers are identical, the current will flow through them identically. Etc. In all those instances, there is causal interaction between the system and that which supervenes (riverbed <> water, planet <> spacetime), and there is no epiphenomenon.
sophiecentaur
#95
Apr29-12, 05:30 AM
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So how does this relate freedom to make a decision totally independently of the 'Physical' world? What do we mean by 'free will' (the most important word in the title of this thread)? If free will is just an illusion - a view that I tend to favour - then it is generated by the mind as a strategy for marshalling an incomprehensible amount of processes that are going on below the surface. These processes are subject to the same influences that are studied in Science but involve many more variables that are discussed in Physics. In the Physics of large numbers (gas laws and QM) the number of variables are much fewer than are involved in the functioning of the Mind and those situations are all dealt with statistically. In the study of the Mind, we have to use the same level of description that our consciousness uses, of course. This is, necessarily, very approximate and superficial - which is how I see a lot of 'Philosophy' working, being propped up by a set of axioms rather than data. Fair enough and very good fun - but is it really anything more?
This may be difficult for people to accept because it turns us more into automatons than perhaps we would like to be. But that explanation doesn't particularly have to interfere with enjoyment of life and appreciation of all the finer things. It just puts things into perspective.
madness
#96
Apr29-12, 05:55 AM
P: 611
Quote Quote by pftest View Post
About the supervenience: isnt that how all physical things work? If two riverbeds have an identical setup, the water will flow through them identically. If two planets are identical, the spacetime will be distorted identically. If two computers are identical, the current will flow through them identically. Etc. In all those instances, there is causal interaction between the system and that which supervenes (riverbed <> water, planet <> spacetime), and there is no epiphenomenon.
The point is to make the distinction between logical and natural supervenience, and to argue that consciousness supervenes naturally but not logically on physical processes. If something is logically reducible to physical processes, then it is in some sense reducible to or identical to those physical processes. If something is naturally supervenience then they are conceptually distinct entities which seem to coincide in our universe.

I think you may have misunderstood supervenience. Riverbed <> water is not an example of supervenience. H20 <> river is a better example, which would count as logical supervenience.
Pythagorean
#97
Apr29-12, 06:00 AM
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Show me a river that's exactly identical to another river. Unique pattern generation isn't unique to humans.

Quote Quote by madness
since it is conceivable that we could have lived in a universe in which these same physical processes lead to a different conscious experience
It could also be that different physical processes can lead to (more or less) the same conscious experience. And in fact, they do at the molecular level. Changing concentration slightly in some local part of the brain would go unnoticed. In most cases, the systems would perform as normal. You already don't attend consciously to much of the plasticity occurring in your CNS right now.

Of course, taking half your brain out or something dramatic like that comes with consequences, but most people still "feel" like the same person, even though they may feel different about themselves. It's not like they lose complete memory of who they are.

http://en.wikipedia.org/wiki/Hemispherectomy#Results

Consciousness is an ill-defined problem. It depends on where you set all the ranges of the parameters of the set of observables that you consider to be consciousness. It's difficulty for us to intuitively understand high-dimensional objects.

It's obviously very difficult to measure subjective experience (which is where some people narrow their definition of consciousness to: the phenomenology), but people attempt other observable measurements.

http://en.wikipedia.org/wiki/Big_Fiv...onality_traits
http://en.wikipedia.org/wiki/Intelligence_quotient
http://en.wikipedia.org/wiki/Graduat...d_Examinations

In most social structures, many different members of society can fit the same role, where some social aspect of their personality is defined by the social vacuum they filled, not some internal emergent property.
madness
#98
Apr29-12, 06:34 AM
P: 611
Quote Quote by Pythagorean View Post
Show me a river that's exactly identical to another river. Unique pattern generation isn't unique to humans.



It could also be that different physical processes can lead to (more or less) the same conscious experience. And in fact, they do at the molecular level. Changing concentration slightly in some local part of the brain would go unnoticed. In most cases, the systems would perform as normal. You already don't attend consciously to much of the plasticity occurring in your CNS right now.

Of course, taking half your brain out or something dramatic like that comes with consequences, but most people still "feel" like the same person, even though they may feel different about themselves. It's not like they lose complete memory of who they are.

http://en.wikipedia.org/wiki/Hemispherectomy#Results

Consciousness is an ill-defined problem. It depends on where you set all the ranges of the parameters of the set of observables that you consider to be consciousness. It's difficulty for us to intuitively understand high-dimensional objects.

It's obviously very difficult to measure subjective experience (which is where some people narrow their definition of consciousness to: the phenomenology), but people attempt other observable measurements.

http://en.wikipedia.org/wiki/Big_Fiv...onality_traits
http://en.wikipedia.org/wiki/Intelligence_quotient
http://en.wikipedia.org/wiki/Graduat...d_Examinations

In most social structures, many different members of society can fit the same role, where some social aspect of their personality is defined by the social vacuum they filled, not some internal emergent property.
I'm not sure if you are trying to argue against what I have been saying because I don't particularly disagree with anything you wrote here. I don't really see how it fits in with what I have been saying. Supervenience doesn't imply a bijection between the base and supervenient properties it just implies that the supervenient properties are somehow entailed in the base properties.
Pythagorean
#99
Apr29-12, 06:54 AM
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not at all meant to be a dispute; just another consideration.
Goodison_Lad
#100
Apr29-12, 07:12 AM
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Quote Quote by John Creighto View Post
If consciousness is not equivalent to thought then what is it?
Good question. Is it possible to be conscious without thought? I think it is - we can be conscious of our thoughts, as we can be conscious of periods when there are no thoughts at all. This view would suggest that consciouness and thought processes are not the same thing, even though they occur in the same arena and usually together.

Quote Quote by Pythagorean View Post
Consciousness is an ill-defined problem. It depends on where you set all the ranges of the parameters of the set of observables that you consider to be consciousness.
Very true. Should a computer pass the the Turing Test to everyone's satisfaction, there could be little doubt that what it was doing was functionally indistiguishable from thought. If this observable is taken to be a key indicator of consciousness, then the computer could reasonably be considered conscious. But I think many observables people suggest are more linked to thinking rather than the conscious experience.

The rather unsettling conclusion that must be accepted if you subscribe to the view that there is no such thing as genuine free will is that there can be no such thing as responsibility for your actions. If free will is an illusion, so is personal responsibility - your actions are the result of the laws of nature in operation, no matter how inscrutable the processes are. So, as an automaton, I cannot reasonably be held to account any more than I can put a computer on trial for some perceived misconduct. I may in practice be held to account - but it wouldn't be reasonable to expect me to have behaved any differently.

And a whole buch of other cherished notions would also be illusory e.g. merit. We already accept that it's silly, really, to praise somebody for how good-looking, tall, intelligent they are because they had nothing to do with it, yet we believe they had some control over their work-rate, generosity and so on.

Just because these are unpleasant conclusions doesn't mean they're not true. But I happen not believe in the existence of so many illusions.
Pythagorean
#101
Apr29-12, 07:19 AM
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I don't agree. You're still accountable. And the other members of your organismal ensemble will make sure of it... in a deterministic matter.
sophiecentaur
#102
Apr29-12, 07:54 AM
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It strikes me that the term 'supervenience', in this context, is just a way of implying a connection that is not necessarily there. Just because 'we make a decision' - which can obviously affect the way that the molecules of the World behave - does not imply anything at all about any 'supremacy' of that decision over the World. That decision can have easily arisen from the random arrangement of some of the atoms in our brains. Assigning any free action of the mind to make this decision and subsequent action is a massive assumption and not justifiable imho. The reason that you think you made a totally thought-out and independent decision need only be because your mind has developed to give you that impression. It is easy to see that some sort of evolutionary advantage could have turned us out in this way.
pftest
#103
Apr29-12, 08:59 AM
P: 271
Quote Quote by madness View Post
The point is to make the distinction between logical and natural supervenience, and to argue that consciousness supervenes naturally but not logically on physical processes. If something is logically reducible to physical processes, then it is in some sense reducible to or identical to those physical processes. If something is naturally supervenience then they are conceptually distinct entities which seem to coincide in our universe.

I think you may have misunderstood supervenience. Riverbed <> water is not an example of supervenience. H20 <> river is a better example, which would count as logical supervenience.
But the thing is that "logical supervenience" is a mental construct. It has no physical meaning. This is not a useful concept for the actual physical relationship between consciousness and the brain.
Q_Goest
#104
Apr29-12, 10:13 AM
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Hi pftest,
Quote Quote by pftest View Post
But the thing is that "logical supervenience" is a mental construct. It has no physical meaning. This is not a useful concept for the actual physical relationship between consciousness and the brain.
Logical supervenience is a concept like the terms "intrinsic" versus "extrinsic", and like those terms, it attempts to pick out a relationship between properties. In this case, logical supervenience tries to pick out properties that relate. So the argument is, "Do mental states logically supervene on physical states?"

For the record, logical supervenience is nicely defined here:
"Logical" supervenience (loosely, "possibility") is also a stricter variant of supervenience: some systems could exist in another world (are "logically" possible), but do not exist in our world (are "naturally" impossible). Elephants with wings are logically possible, but not naturally possible. Systems that are naturally possible are also logically possible, but not viceversa. For example, any situation that violates the laws of nature is logically possible but not naturally possible. Natural supervenience occurs when two sets of properties are systematically and precisely correlated in the natural world. Logical supervenience implies natural supervenience, but not viceversa. In other words, there may be worlds in which two properties are not related the way they are in our world, and therefore two naturally supervenient systems may not be logically supervenient.
Let's then ask the question as Chalmers did, do mental states logically supervene on physical states? Could we for example, imagine a Turing machine that could consistently pass a Turing test that does not support mental states? That is, is it possible that such a machine could only have physical states? Note that mental and physical states here are defined as Jaegwon Kim defines them.

Clearly, a Turing machine produces responces based on algorithmic manipulations of symbols. Those algorithms can be described mathematically and are deterministic. So for each physical state through which a Turing machine passes, there is a physical reason for why it passes through that state. There is no need to appeal to mental states in this case in order to explain why that Turing machine produced the set of responces it did in order to pass the Turing test. Such a machine therefore does not need to have mental states in order to produce the behavior, it only requires the physical states. If we accept this, we can say those mental states to not logically supervene on the physical states since we clearly have no reason to suggest that subjective experiences (which can't be objectively measured) should supervene on those physical states, though we still might claim that those mental states naturally supervene on the physical states.

In fact, we can't know if there are ANY mental states that supervene on physical states if the mental states have no influence over the physical states. That problem is known as the Knowledge Paradox as described for example by Rosenburg and Shoemaker.
Goodison_Lad
#105
Apr29-12, 10:34 AM
P: 59
Quote Quote by Pythagorean View Post
I don't agree. You're still accountable. And the other members of your organismal ensemble will make sure of it... in a deterministic matter.
Legal systems are based on the assumption that free will does exist and that people, generally, are not operating merely deterministically. People are considered to have genuine choice, not just the illusion of it, and the main reason prosecutions occur in the first place is that the accused are believed to have exercised said free will in a way the law disapproves of. It is the very notion of free will that underpins the concept of responsibility, and so people are accordingly held responsible for the consequences of their free choices (an expression which is tautological - what meaningful sense could be made of the idea of a ‘non-free choice’?)

The basis for mitigation is where it judged that free will has been significantly compromised, perhaps to the extent that it was completely absent – mental illness, intellectual impairment, duress etc. Society considers that responsibility and free will are two inseparable sides of the same coin.

So I really don’t think we can have it both ways on this point: we have to be consistent. If our actions are deterministic, we can no more be responsible for them than can a dog for barking, a brick for falling or a supernova for exploding. The fact that other automata might act as though they believe I can be held responsible is simply a further manifestation of their delusion. If they were to fully adopt the view that my behaviour is deterministic, and therefore a direct product of effects immune to non-deterministic intervention, they would have to conclude that the concept of responsibility is a redundant one. We might like it, but it is not logically justified.

However, even if the automata of society were to acknowledge that I had no real free choice, this would not mean that they should necessarily act differently. The imposition of a legal code on an automaton might have the effect of being another deterministic factor affecting its future behaviour.

If responsibility does exist without free will we’d have to consider the possibility of extending the legal system so that we could prosecute animals. Am I any the less a victim of determinism than a pigeon?
sophiecentaur
#106
Apr29-12, 11:04 AM
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Quote Quote by Pythagorean View Post
I don't agree. You're still accountable. And the other members of your organismal ensemble will make sure of it... in a deterministic matter.
This is true, of course. Society evolves to encourage appropriate behaviour. Social pressures and laws have a strong influence on our behaviour (unless we are particularly deviant). There is a social 'system' that tells us we are 'accountable' (only a word) and that influences the way we are likely to behave. Evolution has made sure of that - but no more, in essence, than it governs the behaviour of other animals on a much simpler level.

But the fact that we feel we have a free choice in our actions need to be no more than, as I have said before, a way of rationalising what we have just done or 'decided' on. The illusion of free choice is, in fact, very necessary or we'd just lie back and let it all happen - in the belief that it isn't worth trying. The fact is that all life forms 'try' (i.e. behave as if they were trying). It is just the fact that we are so complex that we had to evolve a consciousness in order to handle it all - so we are 'aware' of trying.
madness
#107
Apr29-12, 12:53 PM
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Quote Quote by pftest View Post
But the thing is that "logical supervenience" is a mental construct. It has no physical meaning. This is not a useful concept for the actual physical relationship between consciousness and the brain.
The external world is a mental construct, the self is a mental construct, I can't think of anything at all that isn't a mental construct.
Pythagorean
#108
Apr29-12, 12:55 PM
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Quote Quote by Goodison_Lad View Post
Legal systems are based on the assumption that free will does exist and that people, generally, are not operating merely deterministically.
Er... no. That's exactly wrong. It only works because it's a deterministic system: because we can have a causative effect on people's actions. If there was no causation, people would make decisions independent of whether it caused them suffering. But because the causation chain is not broken, having and enforcing law continues to work.

Just like any other organism, we change our behavior in light of new information as long as that information passes a threshold in our emotional significance detectors (probably mostly in the amygdala and basal ganglia).

The basis for mitigation is where it judged that free will has been significantly compromised, perhaps to the extent that it was completely absent – mental illness, intellectual impairment, duress etc. Society considers that responsibility and free will are two inseparable sides of the same coin.
No, society doesn't care about free will, only responsibility. All society is, is a bunch of individual voices that want safety and security for themselves, so they don't like people engaging in risky behavior around them. It's really quite normal (especially in mammalian organisms) to have some kind of system that eliminates cheaters, for instance.

What we call mental illness, intellectual impairments, duress, etc, are all examples of when executive function is not dominating prediction and decision measures in the brain. When executive function is broken, people do not care about participating in social acceptance. For instance, frontal lobes complete wiring until between age 3-5, when toddler's start caring. The next major finalization comes in the early 20's with myelination, which finalizes the circuit dynamics in the frontal lobes. This gives the organism a long sample-time while the circuits are still plastic to figure out, negotiate, and even create new social rules and paradigms.

When we get frontal lobe damage or deterioration of any sort (whether from traumatic injury, disease, or other morphological or development abnormalities) we care less about what society thinks. The most famous case of this is Phineas Gage, but there have been countless examples since. Rather than seeing them as lacking free will, we can see these people as having broken their detector/predictor mechanisms for social instances.

I think it's best to distinguish between free will, which is a supernatural idea that some force acts independent of cause and effect, and will power, which is the ability for an organism to execute it's needs/wants (determined from biology and environment). Willpower definitely exists and it's how we judge responsibility.

If somebody always wants to kill you, they are responsible. But if somebody has a disease where there arm swings around wildly at random times, we don't consider them responsible. This is independent of whether the system is deterministic or not; it's only a matter of which system is dominating interactions in the organism.


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