-----Original Message----- From: Bruno Marchal <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Thu, 1 Sep 2005 12:30:20 +0200 Subject: Re: subjective reality

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On 31 Aug 2005, at 16:20, [EMAIL PROTECTED] wrote:

`> I think most people would grant you that the mind-body problem has >`

`not been solved.`

[BM]

`Not meet them so much in my experience. Positive Religious (like`

`Muslim, Catholic, ...) have build-in solution. It is most of the time`

`tabu to question them. Negative Religious (like Atheist) have build-in`

`solution, but are generally not aware of the religiosity of their`

`solutions. Only (serious) philosopher of mind/cognitive scientists are`

`aware of the problem.`

[GK]

`I would leave the "soul" out of my statements. The soul-body problem`

`was solved long time ago.`

[BM] > They would probably would also agree

`> that 3 classes of solutions (at least) have been presented over >`

`the centuries, namely, (1) Physicalist solutions (there is no mind`

`> stuff!) (2) Pure Idealist solutions (there is no body->`

`stuff=matter) and (3) Dualist varieties where both exist and you > try`

`to figure`

`> out how the two stuffs interact etc... It seems to me that your >`

`attempted solution is of type (2), Am I right?`

[BM]

`Well OK. I guess you make the difference between solipsism and`

`idealism which can be realist or platonist. The mind stuff is just`

`numbers and their dreams ...`

[GK] What do numbers dream about? And do the name sheep to go to sleep? > You do however

`> invoke a favorite classical physicalist hypothesis in the form of >`

`YD and than you "turn the tables" on it, so to speak, no?`

[BM]

`YD has nothing with classical physicalism, unless you assume`

`physicalism at the start. YD does not assume a universe physically`

`exist, only that "I" exists and that I am supported by a relatively`

`stable (sheaf) of computations. Actually the use of the YD in the UD`

`reasoning is accompanied by an explicit postulation of a physical`

`universe for making the reasoning easier, but that hypothesis is`

`explicitly eliminated toward the end of the reasoning.`

[GK]

`It seems to me that most of your statements mention assumptions that`

`you accept as starting points only to show that`

`they are not needed in the end! If you assume that the I is "only`

`supported by a stable sheaf of computations" aren't`

you already assuming what you mean to prove?

`> I think that the YD motivation is the weakest link in your chain >`

`(a real Trojan horse because it is physically untenable)`

[BM]

`I really don't understand. To make YD false you must associate`

`yourself to something non-turing emulable. Nobody has ever found a non,`

`turing emulable process. Recall that quantum-like indeterminacy can be`

`retrieved in the self-discourse of self-duplicating machine. Also, with`

`some notable exception like Penrose, everybody accept YD. I teach about`

`it since more than 30 years, and only strict dualists (with assumes`

`explicit substancial soul) criticize it. I told you that those who get`

`my point (of the UD Argument) and still soes not accept the conclusion`

`prefer to abandon Arithmetical Realism. It is an empirical discovery in`

`the sense that (I think we agree here), it is almost nonsense for me to`

`abandon arithmetical realism.`

[GK]

`This is patently false and even more so in your much loved platonic`

`realm which is quite infested with non-digitally computable`

`entities. Turing was careful to provide an example called the Halting`

`problem and he also proved that most real numbers are`

`incomputable but there are many others problems that have been proved`

`Turing un-computable over the years and mathematicians keep finding`

`such instances (tilling problems are one big source of examples).`

`Furthermore people that work in neural network Learning Theory have`

`began to show that there are by-example methods for leaning`

`uncomputable problems which I think are very relevant to this question.`

Read for example: http://citeseer.ist.psu.edu/lathrop96learnability.html

`In physics it is a bit more dificult to argue the uncomputability of`

`natural processes whose phenomenology one has not studied`

`fully but there are surely instances of uncomputable within physical`

`theories that we already know. A classical paper on these`

issues in cosmology is by Hartle and Geroch. You will find it at:

`www.cs.columbia.edu/~library/TR-repository/reports/reports-1997/cucs-012-`

97.ps.gz

`There is also a recent book on the subject (which I have not seen) by`

`Barry Cooper and Piergiorgio Onifreddi.`

You can read a review of it at http://fgc.math.ist.utl.pt/in.pdf

`About QM the problem is not simulating indeterminancy but simulating`

`quantum correlations by local mecanistic means which`

`is how Turing machines compute! Failed attempts to produce such`

`emulations by Wolfram are what makes his book well...`

ridiculous!!!

`About AR I think you also have a misconception of it: AR is the`

`believe that numbers exist, not the ONLY number exist!`

`That would be more like pythagorianism, I believe. In any case I am`

`not suggesting you abandon it...`

> to so > if you use just to demolish it later, why use it at all? [BM]

`This is the eleventh time you confuse "p -> q" with "q -> p". Unless`

`(here) you mean by "demolish YD", the non use of YD in the translation`

`of UDA in arithmetic.`

[GK] So, you don't demolish it, you just abandon it. OK. > Why not proceed to that interview directly? [BM]

`You can. But this is like going from physics to the study of`

`differential equation. Here it would consist to go from cognitive`

`science to pure mathematics. Actually if you justify that probability`

`*must* obey to the Bp -> Dp rule (probability one of p entails the`

`probability of ~p is not one), then OK, you can extract the`

`comp-physics from math alone. But how will you explain the Bp -> Dp`

`rule in that context? Why suppress a motivation which also makes the`

`link with theology: the fact that the comp-doctor cannot pretend that`

`"science" has show that you can survive with an artificial brain (in`

`case comp is true).`

[GK]

`Sorry, but I don't follow here! You get physics but you loose`

`theology!!! Why do you need the theology?`

`> Can that be done and leave your argument intact? That would make it`

a lot more interesting in my opinion...

[BM]

`You are in minority here, but this is just because most people agree`

`with YD (or at least it makes sense as an hypothesis in the cognitive`

`science).`

Bruno [GK] Ditto. Godfrey ________________________________________________________________________

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