[luke warm]

helene_t, on Jun 20 2007, 03:11 AM, said:

~~But he also thought there was a (non-physical?) thing ("mind-stuff") which could exist independently of the brain but somehow interacted with the brain's "control center", the place where sensory input arrives and conscious commands to the body comes out. The problem with this is that if "mind-stuff" can interact with physical things (specifically the brain), it must itself be something physical. ~~

i'll go back and read the rest of this thread, but i wonder why you feel that "mindstuff" (whatever it is, if it is) must be physical in order to interact with the physical... i assume the opposite would be true, that the physical (for example, the brain) can only interact with other physical entities... true?

okay, i've read all so far (excellent topic, helene)... as someone, gerben i think it was, said: we need to define the terms... before going on, let me ask a hypothetical... everyone pretty much knows my beliefs re: God, so this hypothetical will concern him

assume for the sake of argument that God exists (is all knowing, etc) and created the universe... since he is omni in all his attributes, he would know the choices made by me throughout my life... so my question is, would the fact that he knows what i will do in each situation have any bearing upon whether or not my actions are of my own choosing, ie would his foreknowledge negate any vestige of free will?

[hrothgar]

I wrote

>>My understand is that the fundamental disagreement is based on whether or
>>not humans are (indeed) able to perform mental tasks that are impossible for a
>>Turing machine.

>>Penrose is the one asserting a positive. Therefore, the burden of proof rests on
>>him.

Dr Todd replied

Quote

The burden is on him until he has provided a proof.  Once he has done so then it is everyone else's burden to show why the proof is invalid.  In this case, he has provided a proof via example.  Everyone else now has to say that either humans have not done that example or that some fundamental theorem of computability is wrong.  My impression is that they just say "I don't (more like "won't) believe it" and don't directly say which of these two alternatives are wrong.

Can you point to said example?

I wasn't able to find any examples on the net. I was able to find an awful lot of folks saying that Penrose asserts that people are able to solve Turing incomplete problems, but that he never demonstrates this to be true.

For anyone who actually cares about this stuff, there is a decent summary available at http://www.ams.org/n...99602/faris.pdf

Personally, I am reminded of Descartes Ontological Proof of the Existence of "God". This is all very reminiscent of arguing what it means to "Conceive of a being of infinite perfection".

[gwnn]

It would be interesting to establish what exactly "physical" means. It probably means "that to which natural sciences in general or physics in particular assigns energy". Then again, don't all kinds of Qi Gong masters et al claim to describe the soul as some sort of non-material, not yet physically explained energy?

[DrTodd13]

hrothgar, on Jun 20 2007, 01:49 PM, said:

I wrote

>>My understand is that the fundamental disagreement is based on whether or
>>not humans are (indeed) able to perform mental tasks that are impossible for a
>>Turing machine.

>>Penrose is the one asserting a positive. Therefore, the burden of proof rests on
>>him.

Dr Todd replied

Quote

The burden is on him until he has provided a proof.  Once he has done so then it is everyone else's burden to show why the proof is invalid.  In this case, he has provided a proof via example.  Everyone else now has to say that either humans have not done that example or that some fundamental theorem of computability is wrong.  My impression is that they just say "I don't (more like "won't) believe it" and don't directly say which of these two alternatives are wrong.

Can you point to said example?

I wasn't able to find any examples on the net. I was able to find an awful lot of folks saying that Penrose asserts that people are able to solve Turing incomplete problems, but that he never demonstrates this to be true.

For anyone who actually cares about this stuff, there is a decent summary available at http://www.ams.org/n...99602/faris.pdf

Personally, I am reminded of Descartes Ontological Proof of the Existence of "God". This is all very reminiscent of arguing what it means to "Conceive of a being of infinite perfection".

The example is in the book "Shadows of the mind." I don't have it in front of me right now. I guess there is a third possible outcome. One could argue that the example isn't beyond turing completeness.

[Al_U_Card]

luke warm, on Jun 20 2007, 04:37 PM, said:

everyone pretty much knows my beliefs re: God, so this hypothetical will concern him

assume for the sake of argument that God exists (is all knowing, etc) and created the universe... since he is omni in all his attributes, he would know the choices made by me throughout my life... so my question is, would the fact that he knows what i will do in each situation have any bearing upon whether or not my actions are of my own choosing, ie would his foreknowledge negate any vestige of free will?

Were you not created in its own image? An image cannot be an idol as that would go against a commandment, so you must be a part of the whole but including all of its attributes whether expressed and perceived or not. (Like a hologram.)

So, you are here and it is there. You are doing something here that it cannot do from there. Since you are the same, you have the same purpose, just a different mode of expression. So, you both are doing what you must to fulfill your needs. How you do these things that are required determines how well you accomplish your task.

Good luck.

[helene_t]

Al said:

What would you like consciousness to be?

You mean, how exactly it should be defined? In a concise way, preferably, but unfortunately I cannot think of a concise definition. If those "strong AI" guys win at the end, they could define it in technical terms ("we call a computer 'conscious' if it is able to perform 4'th order mega-quasi-wizard-Turing operations" or some such). I'd like that, at least if I learned enough about AI to understand such a definition.

Or do you mean what I'd like its nature to be? I prefer the strong AI notion, i.e. it comes from complexity alone, doesn't matter if the stuff it's made of is biological or electronic, behaves according to classical physics or some Penrosian meta-quantum- physics. This is because I worship Occam's Razor.

Todd said:

Penrose's argument is that the human brain can do things that are provably un-doable for a classic computer/Turing machine.

In "The Emperor's New Mind" he gives this example: A Turing Machine wouldn't be able to prove Godel's Theorem. As Richard says, very few scientists and philosophers take this argument serious. My own assessment was that it sounded like yet another silly "This statement is wrong"-paradox. Then again, very few scientists and philosophers understand Godel's Theorem. It's possible that Penrose is just too far ahead of his time.

jimmy said:

i wonder why you feel that "mindstuff" (whatever it is, if it is) must be physical in order to interact with the physical... i assume the opposite would be true, that the physical (for example, the brain) can only interact with other physical entities... true?

According to Denett, this is not just what I feel, it's something virtually all contemporary philosophers and scientists agree on. Even Descartes himself recognized that it was a big problem, it was just that he couldn't imagine any alternative. But the following question is crucial:

csaba said:

It would be interesting to establish what exactly "physical" means.

Today, physics is pretty much the theory of "everything", which renders "x is something physical" nearly tautological. One could imagine the objective World consisting of three classes of objects:
- physical objects which (this is the defining property for physical objects) interact with other physical objects
- nonphysical objects, such as spirits, which (defining property for nonphysical objects) don't interact with physical objects
- the human mind which is the only object that can interact with both. I suppose you could put "God" in this category as well, if you want.
In Descartes' time, nearly everybody saw "living objects" as possessing non-physical properties: the spiritual was interacting with the physical in animals, the human soma, maybe even in plants. So Descartes was outrageously materialistic for his time. Today, physics has become "everything" so we see Descartes as a dualist. But he was very much monist for his time.

Today, that discussion is obsolete, but maybe it has reapeared as the controversy of interpretation of quantum mechanics. Suppose that the quantum wave function (before it collapses) and determined quantum states (after the wave collapses) are deemed "physical", while the models of those physical things as imagined by a human mind are deemned non-physical. This is not to suggest that there is anything "magical" about the human brain: it's just that the information stored in the human brain (or a computer, or a paper book) is called non-physical if we focus on the information alone and don't care what particular storage medium is has been written to.

Now if one subscribes to Penrose's ideas, and/or to the notion that information is what is "really" out there and matter, space and energy are just abstractions, then the distsinction between physical and non-physical becomes blured, at least to me. But that might just be because I happen not to be able to think clearly about this.

[Quantumcat]

Hi all, may I add my two cents?

In the webct page for one of my physics courses (quantum mechanics) we have a discussion going about what exactly is the definition of reality and the place of quantum mechanics in it. Here is my last reply (which I put a lot of effort into writing), maybe you guys might have some ideas on the subject too.

Here's a necessary condition for any plausible collective definition of "reality"... and from which we can deduce the inevitable 'non-realist' conclusions of quantum mechanics.

The condition also allows us to escape the vacuous and pathological discussions on the acceptance of a precise definition of "reality", prevalent in other threads of this
discussion board.

Our definition of "reality" or what is "real" must invariably be equivalent to a definition for "existence" or what "exists", as the following (reductio ad absurdum) argument demonstrates:

Suppose "existence" is a necessary condition for "reality", but not conversely.
That is, suppose that what we define to be real must exist (physically, metaphysically, etc...), but that what exists need not necessarily be defined as "real" (e.g. hallucinations, voices of the schizophrenic mind, etc...).

By Russell's Paradox, there does not exist a set of all sets. Thus, the set of all things "real", called it R, whatever our definition of reality may be, cannot be a set of all sets. Hence, there is a larger set in the universe (or possibly beyond) in which R is a proper subset.

Moreover then, by the definition of R - the set of all things real - there must *exist* at least one thing that is "not real" in a larger set.

Therefore, any realist theory of physics is not complete, since it cannot describe every existing thing. So the mission of modern physics - to conjure up a "theory of everything" of the universe is bound to fail. Whence, physicists should just give up their practice right now.

Therefore, in order to halt this disparagement of the pursuit of Physics we (physicists) cannot speak of a notion of reality of a thing without knowing whether or not such a thing exists. That is to say, all things not real must be defined to be non-existent.

However, this goes precisely into the interpretation of quantum mechanics we have learnt in class - that what we cannot see cannot be "real" (again, regardless of our definition of "reality") - because we cannot know what exists unless we have the observable evidence.

Thus, reality cannot cohesively extend beyond what we can observe to be existing!

The choice is clear: accept the consequences of quantum mechanics, or, that a full
understanding of the universe is eternally beyond our reach.

[mike777]

helene_t, on Jun 21 2007, 02:45 AM, said:

Al said:

What would you like consciousness to be?

You mean, how exactly it should be defined? In a concise way, preferably, but unfortunately I cannot think of a concise definition. If those "strong AI" guys win at the end, they could define it in technical terms ("we call a computer 'conscious' if it is able to perform 4'th order mega-quasi-wizard-Turing operations" or some such). I'd like that, at least if I learned enough about AI to understand such a definition.

Or do you mean what I'd like its nature to be? I prefer the strong AI notion, i.e. it comes from complexity alone, doesn't matter if the stuff it's made of is biological or electronic, behaves according to classical physics or some Penrosian meta-quantum- physics. This is because I worship Occam's Razor.

Todd said:

Penrose's argument is that the human brain can do things that are provably un-doable for a classic computer/Turing machine.

In "The Emperor's New Mind" he gives this example: A Turing Machine wouldn't be able to prove Godel's Theorem. As Richard says, very few scientists and philosophers take this argument serious. My own assessment was that it sounded like yet another silly "This statement is wrong"-paradox. Then again, very few scientists and philosophers understand Godel's Theorem. It's possible that Penrose is just too far ahead of his time.

jimmy said:

i wonder why you feel that "mindstuff" (whatever it is, if it is) must be physical in order to interact with the physical... i assume the opposite would be true, that the physical (for example, the brain) can only interact with other physical entities... true?

According to Denett, this is not just what I feel, it's something virtually all contemporary philosophers and scientists agree on. Even Descartes himself recognized that it was a big problem, it was just that he couldn't imagine any alternative. But the following question is crucial:

csaba said:

It would be interesting to establish what exactly "physical" means.

Today, physics is pretty much the theory of "everything", which renders "x is something physical" nearly tautological. One could imagine the objective World consisting of three classes of objects:
- physical objects which (this is the defining property for physical objects) interact with other physical objects
- nonphysical objects, such as spirits, which (defining property for nonphysical objects) don't interact with physical objects
- the human mind which is the only object that can interact with both. I suppose you could put "God" in this category as well, if you want.
In Descartes' time, nearly everybody saw "living objects" as possessing non-physical properties: the spiritual was interacting with the physical in animals, the human soma, maybe even in plants. So Descartes was outrageously materialistic for his time. Today, physics has become "everything" so we see Descartes as a dualist. But he was very much monist for his time.

Not to hijack your thread Helene but per my numerous threads on strong AI, most are more concerned with intelligience and not is AI alive or does it have a consciousness or self awareness.

In other words, can strong AI be Intelligent given some generally accepted definition and can it be measured and compared to humans?

If that is not against the laws of science then the prediction is:
1) Watch for huge advances in brain scanning and understanding of the brain.
2) If so then by 2029 AI equals one human in intelligence
3) by 2050 AI equals hundreds of millions times the entire human race.

[mike777]

To sidestep the issue of freewill if the question is can we control an AI that is hundreds of millions of times more intelligent than the entire human race, my guess is No.

I am not calling it freewill, I am just saying humans will not control it or fully understand it.

[helene_t]

Hi Quantumcat,

In mathematics, something "exists" if it could logically exist, according to the axioms you have accepted. For example, Rusells paradox relies on the axiom of specification which says that if a set M exists and p is any predictate, then the subset {x in M | p(x)} exists. To a mathematician, pink elephants are as "existing" as grey ones. You might say that we have no empric evidence for pink elephants, but empiric evidence is irrelevant in math. This is important when you invoke Rusell's paradox, since Rusell's paradox is a mathematical theorem: it speaks about "existence" in the mathematical sense.

It could also be that there is no set of all real things. If the class of real things is a propper class, Rusell's paradox does not apply.

You say

Quote

Thus, the set of all things "real", called it R, whatever our definition of reality may be, cannot be a set of all sets. Hence, there is a larger set in the universe (or possibly beyond) in which R is a proper subset.

But this proves the opposite of your statement

Quote

Our definition of "reality" or what is "real" must invariably be equivalent to a definition for "existence" or what "exists"

doesn't it? I'm confused.

However, your final conclusion

Quote

However, this goes precisely into the interpretation of quantum mechanics we have learnt in class - that what we cannot see cannot be "real" (again, regardless of our definition of "reality") - because we cannot know what exists unless we have the observable evidence.

could maybe be defended by the argument that any non-awkward mathematical model for the real World must necesarily rely on the existence of non-observable facts, for a number of reasons. For example, due to the final bandwidth of measurement equipment there's only a countable set of questions we can ask.

[mike777]

"However, this goes precisely into the interpretation of quantum mechanics we have learnt in class - that what we cannot see cannot be "real" (again, regardless of our definition of "reality") - because we cannot know what exists unless we have the observable evidence.


could maybe be defended by the argument that any non-awkward mathematical model for the real World must necesarily rely on the existence of non-observable facts, for a number of reasons. For example, due to the final bandwidth of measurement equipment there's only a countable set of questions we can ask. "


Is this the whole Black Swan debate?

I have never seen a Black Swan, no one has ever observed a Black Swan, therefore we conclude what? This is the limitations of Mathmatics?

BTw and the limitations of risk management in my area of Finance?

[Quantumcat]

Yes, the pink elephants exist, like hallunications and dreams do, what I meant is real -> existence but existence does not -> real. Is that what you were asking? I'm not sure.

[mike777]

Quantumcat, on Jun 21 2007, 03:35 AM, said:

Yes, the pink elephants exist, like hallunications and dreams do, what I meant is real -> existence but existence does not -> real. Is that what you were asking? I'm not sure.

NO I am not asking if Pink elephants exist.

I am asking can you prove they do not or we should not be concerned about them in risk management?

Was 9-11 a Pink Elephant?
Was Hitler invading France a Pink Elephant?

Can AI's be intelligent or are they Pink Elephants?

OTOH should I just be optimistic and say heck no one has every seen one, why plan for it?

[Quantumcat]

Hahahahaha, I was replying to helene's post, not yours! Sorry for the misunderstanding

[helene_t]

DrTodd13, on Jun 20 2007, 08:06 PM, said:

I don't want the existence of free will to be disproven because I know what the societal ramifications would be.  Philosophy matters.  People might not be able to say what philosophy is influencing them but it does trickle down and influence people.  The pretty obvious result of masses of people believing that free will does not exist would be total mayhem.  No one is responsible for their actions because they can't control them.  Therefore, we shouldn't punish them.  Out the window has to go all notions of right and wrong.  Murder is just the destruction of a biological machine.

I strongly disagree with this line of thought. There may be exceptions but in general I think that mature people with normal intelligence and normal moral instincts deserve to be told the truth. Of course we don't know for sure what the truth is, but if you want to withhold some candidate truth, it should mainly be because it is implausible or incomprehensible. Fear that it might cause the erosion of morality is a weak argument, I think.

This is because otherwise you teach people to behave morally correct because of some false premise. Then morality will disappear as soon as the falseness of the premise is disclosed.

Example: I was raised in the postmodernistic era of the 70s. As such I was told that violence is un-natural since the human nature is good. My inference from this (right or wrong) was that I could consult Mother Nature for moral advice. As soon as I grew up to realize that violence, rape, genocide, destruction of the environment, selfishness etc. etc. are all perfectly natural human traits, I might have lost my moral judgement. Thankfully I did not (at least I don't think so, lol) because I was smart enough to realize that all those "nature is good"-cliches are bullshit. There is nothing paradoxal by something being natural and morally condemnable at the same time.

Case in point: I think it's ok to punish a criminal even if he "really" has no free will. The illusion of free will, i.e. the ability to avoid behaviour that can be projected to be punished, is more than enough. Also, I think it's morally wrong to murder no matter if what you destroy is seen as a biological machine, a divine spirit or whatever.

[helene_t]

Quantumcat, on Jun 21 2007, 10:35 AM, said:

Yes, the pink elephants exist, like hallunications and dreams do, what I meant is real -> existence but existence does not -> real. Is that what you were asking? I'm not sure.

I understand you distinction but it seems to me that you first state that all existing things must also be real, and then you prove the opposit. Maybe I misread or maybe you made a typo. I think what you want to say is that there must be some existing things that are not real.

This is difficult to formalize since "reality" has no meaning in math.

[mike777]

"Case in point: I think it's ok to punish a criminal even if he "really" has no free will. The illusion of free will is more than enough. Also, I think it's morally wrong to murder no matter if what you destroy is seen as a bilogical machine, a divine spirit or whatever."

I am not sure I would choose the word punish, but the word self protection or preservation. What that "best" means may very well be a process of trial and error on a massive scale. If the nature of someone is to sin and by definition one cannot change their own nature without supernatural assistance some longterm process of trial and error may kick in.

[helene_t]

mike777, on Jun 21 2007, 10:33 AM, said:

Is this the whole Black Swan debate?

I have never seen a Black Swan, no one has ever observed a Black Swan, therefore we conclude what? This is the limitations of Mathmatics?

BTw and the limitations of risk management in my area of Finance?

Sorry, I gave a bad example. I should have stated the assumption that there is evidence against the existense of pink elephants, not merely that there is no evidence for the existence of pink elephants.

As for risk management: If you have never seen (or heard of) a black swan, and someone offers you an investment opportunity that would loose only in the case of the dicovery of black swans, your judgement is probably ok. You may make a mistake in retrospect, but your field is not supposed to be excat science. You do the best you can. Avoiding any hypothetical risk would be a sure long-term looser.

[mike777]

helene_t, on Jun 21 2007, 04:04 AM, said:

mike777, on Jun 21 2007, 10:33 AM, said:

Is this the whole Black Swan debate?

I have never seen a Black Swan, no one has ever observed a Black Swan, therefore we conclude what? This is the limitations of Mathmatics?

BTw and the limitations of risk management in my area of Finance?

Sorry, I gave a bad example. I should have stated the assumption that there is evidence against the existense of pink elephants, not merely that there is no evidence for the existence of pink elephants.

As for risk management: If you have never seen (or heard of) a black swan, and someone offers you an investment opportunity that would loose only in the case of the dicovery of black swans, your judgement is probably ok. You may make a mistake in retrospect, but your field is not supposed to be excat science. You do the best you can. Avoiding any hypothetical risk would be a sure long-term looser.

Helene

If I own the twin towers in New York and there is a Black Swan hypothetical risk that a bunch of clowns with box cutters will crash them down, I need to protect against that and still make a buck.

No one has ever seen such a thing, it is highly improbable, I cannot even prove how to bring down the world trade towers with box cutters as the only weapon, maybe once in a million years but yet they seem to happen more often than that.

[helene_t]

hrothgar, on Jun 20 2007, 03:46 PM, said:

This question is a specific example of a large class that I simply don't bother to worry about. 

I took a course on philosophy back in undergrad.  We spent lots of time looking at different ontological proofs for existence of God and (slowly) branching out into Locke, Berkeley, and Hume.  At the end of the class, the only real conclusion that I reach was that none of this matters.

Of course it's more interesting to discuss the existence of well-defined things under well-defined assumptions. For example, the existence of intergers X>0, Y>0,Z>0 and p>2 so that
Z^p = X^p + Y^p
under the Peano axioms was a well-defined (and therefore interesting) problem until it was solved some 15 years ago, I think.

I think that the existence of God was an interesting question 3500 years ago when he was defined as an old erremit on the top of the Olympus, who could create thunder knocking the clouds (or something like that). Then it was a testable hypothesis. By the same token, the existence of animal inteligence is much more interesting to me than animal consciousness, simply because there are clearer definitions of what it means.

However, recent progress in brain imaging has made it possible to test some hypotheses about consciousness. One might insist that they are not about "real" consciousness, depending on how one defines "consciousness". But I think that enormous progress has already been made. Fourty years ago, humans and other animals were just black boxes whose stimulus-response-statistics showed some correlations. Today we have mental states: emotions and memory are scientific concepts and they are linked to neurophysiology.