How physicists handle the idea of Free Will?


by fbs7
Tags: free, handle, physicists
Ferris_bg
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#145
May2-12, 06:14 AM
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Quote Quote by madness View Post
Nothing stops different brains from producing the same mind under supervenience, but it is not part of the definition.
Yes, you are right it's not, but its part of what non-reductive physicalism is.

[Mind-body supervenience] The mental supervenes on the physical in that any two things (objects, events, organisms, persons, etc.) exactly alike in all physical properties cannot differ in respect of mental properties. That is, physical indiscernibility entails psychological indiscernibility.

What you mean by "overall experience as a whole"? Take for example the feeling of surprise. How it feels to be surprised at 5 and at 40? Do you think its different?
madness
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#146
May2-12, 06:24 AM
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Quote Quote by Ferris_bg View Post
Yes, you are right it's not, but its part of what non-reductive physicalism is.

[Mind-body supervenience] The mental supervenes on the physical in that any two things (objects, events, organisms, persons, etc.) exactly alike in all physical properties cannot differ in respect of mental properties. That is, physical indiscernibility entails psychological indiscernibility.
Yes but psychological indiscernibility does not entail physical indiscernibility. This means that different brains do not necessarily produce different mental states according to physicalism.

Quote Quote by Ferris_bg View Post
What you mean by "overall experience as a whole"? Take for example the feeling of surprise. How it feels to be surprised at 5 and at 40? Do you think its different?
I mean the total contents of your mental/conscious state at that time. You have qualia such as the experience of redness or the smell of roses which may be largely the same between individuals, but the overall mental state is different. I don't think it is really possible to feel surprised in the same way twice or between two individuals due to the myriad associated mental states which are unique to an individual at that time. One of the most important properties of conscious states is the level of integration, meaning that each component cannot be analysed separately http://en.wikipedia.org/wiki/Integra...rmation_Theory.
Ferris_bg
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#147
May2-12, 06:47 AM
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We don't know if there are any mental states, which are the same for different individuals. We can only guess. That's why I gave the example with the same person at different ages. What I know from introspection is that the same chemicals can cause me different qualia, but I am also able to experience some things the same way, as when I was a kid. That's why the reductive physicalism has serious problems, because according to it, different brain state always produces different mental state.

And IIT is interesting, but we don't know if the mental reduces to information.
Pythagorean
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#148
May2-12, 11:17 AM
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Quote Quote by Ferris_bg View Post
We don't know if there are any mental states, which are the same for different individuals. We can only guess. That's why I gave the example with the same person at different ages. What I know from introspection is that the same chemicals can cause me different qualia, but I am also able to experience some things the same way, as when I was a kid. That's why the reductive physicalism has serious problems, because according to it, different brain state always produces different mental state.

And IIT is interesting, but we don't know if the mental reduces to information.
That doesn't really appear to be an argument of merit to me. Firstly, you can't say whether you experience things the same way as when you were a kid. Even if you could, it wouldn't be particularly surprising. There are several hierarchies in the brain. One particular sensory experience memory may be contained in a small region of somatic cortex. It's functional organization can be preserved. It (the chunk of somatic cortex) may even have several different physical states over the course of the person's lifetime, yet still produce the same result. Degeneracy and redundancy are fairly common in biological systems (and it makes sense, of course, for such complex machines to keep running in a chaotic environment requires fail-safes, which is what degeneracy brings you).

On the other side of the hierarchy, the representation of self is widely distributed throughout the brain. You can take half of somebody's brain out and they could still feel mostly like themselves (and even mostly recover given enough time). Of course, they're not going to be the same person in totality. Older people, who have reduced plasticity, might never recover (i.e. they will suffer some form of retardation because their brain has already committed regions to particular tasks). Whereas a child who still has a lot of plasticity is likely to fully recover. Because it has plasticity, the system is able to reorganize into a complete set (but now with half the computing power, you might say).
madness
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#149
May2-12, 05:32 PM
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Quote Quote by Ferris_bg View Post
That's why the reductive physicalism has serious problems, because according to it, different brain state always produces different mental state.
This not true at all. I don't even agree with physicalism but physicalists do not believe what you say here.
Ferris_bg
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#150
May3-12, 02:09 AM
P: 88
Type physicalism (also known as reductive materialism, type identity theory, mind-brain identity theory and identity theory of mind) is a physicalist theory, in philosophy of mind. It asserts that mental events can be grouped into types, and can then be correlated with types of physical events in the brain. For example, one type of mental event like "mental pains" will, presumably, turn out to be describing one type of physical event (like C-fiber firings). [wikipedia]

Quote Quote by http://www.iep.utm.edu/identity/#H4
Putnam’s argument can be paraphrased as follows: (1) according to the Mind-Brain Type Identity theorist (at least post-Armstrong), for every mental state there is a unique physical-chemical state of the brain such that a life-form can be in that mental state if and only if it is in that physical state. (2) It seems quite plausible to hold, as an empirical hypothesis, that physically possible life-forms can be in the same mental state without having brains in the same unique physical-chemical state. (3) Therefore, it is highly unlikely that the Mind-Brain Type Identity theorist is correct.
Quote Quote by The Multiple Realization Argument, Philosophy of Mind, Jaegwon Kim
Type physicalism says that pain is C-fiber excitation. But that implies that unless an organism has C-fibers or a brain of an appropriate biological structure, it cannot have pain. But aren't there pain-capable organisms, like reptiles and mollusks, with brains very different from the human
brain? Perhaps in these species the neurons that work as nociceptive neurons--pain-sensitive neurons--aren't like human C-fibers at all. Can the type physicalist reply that it should be possible to come up with a more abstract and general physiological description of a brain state common to all organisms, across all species, that are in pain state? This is highly unlikely, but how about inorganic systems? Could there not be intelligent extraterrestrial creatures with a complex and rich mental life, one that is very much like ours, but whose biology is not carbon-based? And isn't it conceivable--in fact, at least nomologically if not practically possible--to build intelligent electromechanical systems (that is, robots) to which we would be willing to attribute various mental states? Moreover, the neural substrates of certain mental functions can differ from person to person and may change over time even in a single individual through maturation, learning, and injuries to the brain. We should keep in mind that if pain is identical with physical state C, then pain is identical with state C not only in actual organisms and systems but in all possible organisms and systems.

These considerations are usually taken to show that any given mental state is "multiply realizable" in a large variety of physical/biological structures, with the consequence that it is not possible to identify a mental state with a physical state. If pain is identical with a physical state, it must be identical with some particular physical state; but there are indefinitely many physical states that can "realize" (or "instantiate," "implement," etc.) pain in all sorts of pain-capable organisms and systems. So pain, as a type of mental state, cannot be a neural-state type or any other physical-state type.

This, in brief, is the influential "multiple realization" argument against type physicalism Hilary Putnam advanced in the late 1960s (we will recur to multiple realization in the next chapter). It had a critical impact on the way philosophy of mind has developed since then: It effectively retired type physicalism as the reigning doctrine on the mind-body problem, throwing the very term "reductionism" into disrepute and ushering in the era of "nonreductive physicalism." Further, it inspired a new conception of mentality, "functionalism," which has been highly influential since the 1970s and which is arguably still the most widely accepted view on the nature of mind.
pftest
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#151
May3-12, 02:44 AM
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When talking about the mind<>body relationship, i think the first thing a physicalist position needs, is a matching example of a physical<>physical relationship. Is the mind<>brain relationship the same as the water<>riverbed relationship? A rock<>its molecules?

If a physicalist cannot find any relationship in the physical world that matches their ideas of the mind<>body relationship, then by definition it is not a physical relationship and it cannot have arisen in a physical manner.
madness
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#152
May3-12, 05:00 AM
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Quote Quote by pftest View Post
When talking about the mind<>body relationship, i think the first thing a physicalist position needs, is a matching example of a physical<>physical relationship. Is the mind<>brain relationship the same as the water<>riverbed relationship? A rock<>its molecules?

If a physicalist cannot find any relationship in the physical world that matches their ideas of the mind<>body relationship, then by definition it is not a physical relationship and it cannot have arisen in a physical manner.
I think its useful to distinguish between the psychological and phenomenal aspects of mental states. For example, perception and sensation are both aspects of the same mental state. Perception involves the recognition and interpretation of something, whereas sensation is the conscious experience of redness or the smell of a flower. In general, physicalism seems to be on the right track to explaining most psychological mental states (e.g. memory, perception, learning) but there is no hint of a solution to the phenomenal states in terms of physical interactions. As far as I know, the standard approach of a physicalist is to simply deny the existence of any phenomenal states.
Ferris_bg
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#153
May3-12, 05:20 AM
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There is a difference (psychological vs phenomenal) for sure and the Knowledge Argument is still a serious challenge for physicalism.
madness
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#154
May3-12, 06:20 AM
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Quote Quote by Ferris_bg View Post
There is a difference (psychological vs phenomenal) for sure and the Knowledge Argument is still a serious challenge for physicalism.
I agree that the knowledge argument shows a gap in our understanding about how phenomenal states arise or what they even are, but I'm not sure there is any real knowledge or information in a qualia like the experience of redness. I can tell you I am seeing red, but I can't give you any information on what that means.
pftest
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#155
May4-12, 04:18 AM
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I just read the functionalism quote, from Ferris_bg, and i noticed the bold bit:

Type physicalism says that pain is C-fiber excitation. But that implies that unless an organism has C-fibers or a brain of an appropriate biological structure, it cannot have pain. But aren't there pain-capable organisms, like reptiles and mollusks, with brains very different from the human
brain? Perhaps in these species the neurons that work as nociceptive neurons--pain-sensitive neurons--aren't like human C-fibers at all. Can the type physicalist reply that it should be possible to come up with a more abstract and general physiological description of a brain state common to all organisms, across all species, that are in pain state? This is highly unlikely, but how about inorganic systems? Could there not be intelligent extraterrestrial creatures with a complex and rich mental life, one that is very much like ours, but whose biology is not carbon-based? And isn't it conceivable--in fact, at least nomologically if not practically possible--to build intelligent electromechanical systems (that is, robots) to which we would be willing to attribute various mental states? Moreover, the neural substrates of certain mental functions can differ from person to person and may change over time even in a single individual through maturation, learning, and injuries to the brain. We should keep in mind that if pain is identical with physical state C, then pain is identical with state C not only in actual organisms and systems but in all possible organisms and systems.

These considerations are usually taken to show that any given mental state is "multiply realizable" in a large variety of physical/biological structures, with the consequence that it is not possible to identify a mental state with a physical state. If pain is identical with a physical state, it must be identical with some particular physical state; but there are indefinitely many physical states that can "realize" (or "instantiate," "implement," etc.) pain in all sorts of pain-capable organisms and systems. So pain, as a type of mental state, cannot be a neural-state type or any other physical-state type.

This, in brief, is the influential "multiple realization" argument against type physicalism Hilary Putnam advanced in the late 1960s (we will recur to multiple realization in the next chapter). It had a critical impact on the way philosophy of mind has developed since then: It effectively retired type physicalism as the reigning doctrine on the mind-body problem, throwing the very term "reductionism" into disrepute and ushering in the era of "nonreductive physicalism." Further, it inspired a new conception of mentality, "functionalism," which has been highly influential since the 1970s and which is arguably still the most widely accepted view on the nature of mind.
What i see in the bold bit, is that functionalism or multiple realization, cannot be a physicalist position. It holds an abstract entity (abstract functional similarities between physical systems such as brains and computers) to be the cause of consciousness. But abstractions are by definition conceptual in nature, so they cannot be the origin of consciousness. For example, my mind can recognise the abstract similarities between 2 apples and 2 pears, namely that there are 2 of both. But if i claim that such a "twoness" is what brought the first abstraction into existence, it would be the equivalent of saying the first egg came from a previous egg.
Ferris_bg
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#156
May4-12, 04:52 AM
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Functionalism falls in the property dualism category (aka non-reductive physicalism). As you can see from the picture in wiki, the mental is considered a "property" of the physical substance. The problem with these types of theories is that they can't account for mental causation aka the mental is epiphenomenal. And epiphenomenalism is considered by many as not logically coherent (search the forum for Q_Goest posts about the "knowledge paradox").
sophiecentaur
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#157
May4-12, 06:10 AM
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This is all, pretty clearly 'angels-on-pinheads' stuff. I justify this remark on the grounds that, every time a question is asked, a brand new word is coined with which to answer it. I have read more 'new' words on this thread than on all the QM and GR threads put together.
The way Philosophy is going seems to be highly divergent, which is directly against the reductionist aims of yer proper Science. It doesn't surprise me that emotional states, sensations and ideas cannot be linked coherently with physical states simply because the system is trying to examine itself with the very tools that it is examining.

At the simplest level, we look around us and see a whole range of physical arrangements that achieve the same functions amongst animals - think of the number of alternative eye structures that have developed to achieve 'vision' of some sort. We say that a fly has "seen us" without mentioning the fact that its eye and image processing is entirely different from ours.
So, in the context of brain / mind studies, how can it be claimed that mental states can be associated with one particular physical structure when there is no way, even, of equating mental states between one individual and another? As with the earlier example of colour vision and sensation, we can only compare mental states by reference to some external physical setup (a questionaire, Ishihara Colour test etc.) and by communication between individuals. This is just not good enough to produce any more than an arm waving theory, although humans are more than capable of making do with this limitation in their everyday dealings with each other and when selecting paints for their houses.
It seems to me that there is an equivalent of the Heisenberg Uncertainty principle at work here between the Physical and the Mental situation. As long as Philosophers want it to be otherwise then their 'faith' will keep them attempting the unattainable and generating yet more new terms in the process.
Darken-Sol
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#158
May4-12, 09:21 AM
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why look at the process? free will is simply the ability to change our mind. i can decide to flip a coin and roll with the out come on a certain question. bam. heads. i didnt want heads maybe ill flip again. or i can decide this whole coin thing is stupid. i cud even decide to do nothing. where do i lack free will?
Pythagorean
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May4-12, 09:31 AM
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The question is whether your choices were predetermined. We k ow we can do what we want, but is what we want predetermined? I think so, I think there's a mechanism for liking and not liking things.

For instance, people can like or dislike food as the pertain to deficiencies in their biochemistry or people will fear things if those things have presented trauma in the past. Other preferences may just be a matter of chance ("how the molecules fell").
Darken-Sol
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May4-12, 09:43 AM
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Quote Quote by Pythagorean View Post
The question is whether your choices were predetermined. We k ow we can do what we want, but is what we want predetermined? I think so, I think there's a mechanism for liking and not liking things.

For instance, people can like or dislike food as the pertain to deficiencies in their biochemistry or people will fear things if those things have presented trauma in the past. Other preferences may just be a matter of chance ("how the molecules fell").
i get that. but i do things i dont like almost daily. i have a sense of duty. i choose to do these things, yet some times i choose not to. the coin thing is helpful, to me it is the universes opinion. choices are influenced, not predetermined.
Pythagorean
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May4-12, 09:48 AM
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Quote Quote by Ferris_bg View Post
Functionalism falls in the property dualism category (aka non-reductive physicalism). As you can see from the picture in wiki, the mental is considered a "property" of the physical substance. The problem with these types of theories is that they can't account for mental causation aka the mental is epiphenomenal. And epiphenomenalism is considered by many as not logically coherent (search the forum for Q_Goest posts about the "knowledge paradox").
I don't know. I think, for the most part, most humans experience (for instance) yellow the same way. Especially when it has a light background

There's also a whole subject of color psychology that shows how colors influence psychological states and it's fairly consistent across humans.

And we don't need to account for mental causation... it doesn't seem to exist.
Darken-Sol
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#162
May4-12, 10:11 AM
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why is it called free will any way? it seems to me any decision has a cost. whether we factor that in or disregard it is still our choice.


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