Re: subjective reality

From: Bruno Marchal <>
Date: Thu, 1 Sep 2005 12:30:20 +0200

On 31 Aug 2005, at 16:20, wrote:

> I think most people would grant you that the mind-body problem has
> not been solved.

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.

> 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?

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 ...

> 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?

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.

> I think that the YD motivation is the weakest link in your chain
> (a real Trojan horse because it is physically untenable)

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.

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

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.

> Why not proceed to that interview directly?

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).

> Can that be done and leave your argument intact? That would make it
> a lot more interesting in my opinion...

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

Received on Thu Sep 01 2005 - 06:37:18 PDT

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