Re: Emulation and Stuff

From: Bruno Marchal <>
Date: Fri, 21 Aug 2009 21:49:06 +0200

On 21 Aug 2009, at 09:33, Flammarion wrote:

> On 20 Aug, 00:28, Bruno Marchal <> wrote:
>> On 19 Aug 2009, at 22:21, Flammarion wrote:
>>> Where he says computation can happen without any physicial process
>>> at
>>> all. I don't see any evidence for that
>> I am explaining this right now.
>>> Only Bruno thinks computation trancends matter.
>> The notion of computation and computability have been discovered by
>> Mathematicians working around the foundation crisis of math after the
>> discovery by Cantor and others of paradoxes in set theory.
>> The idea is that computation should be redefined as physical
>> computation is a very recent one, and is due to people like David
>> Deustch and Landauer. And it does not really work as such. Deutsch
>> "reconstruction" of the Post-Church-Turing thesis is really a
>> different thesis.
> Of course you can have theoretical
> truths about computation
> But show me something that has been computed by
> an immaterial computer.

A Schmidhuberian computationalist would probably answer: look around
you. But I have explained why this is not enough, and why a prori comp
makes the observable reality not the output of one program (but a view
from inside from all execution of all programs).

  I can only hope you will work on the UDA+MGA, and understand that
"non-theoretical" truth have to be redefined as theoretical
possibilities (consistencies) observed from inside (from some first
person point of view).

Comp, or CTM, leads to a "many types no token" view of reality. Token
are seen as such by being appearances from the point of view of an
abstract subject coupled to an (infinity of) abstract computations.

>>> CTM *implies* materialism, and the MGA doesn't work.
>> CTM is neutral on materialism, even if many materialist use
>> incorrectly comp to put the mind body problem under the rug. UDA,
>> including MGA, shows why this fails.
>> What is in MGA which does not work?
> It's a reductio of the idea that mental states
> supervene on computational states.
> CTM must be cast as the claim
> that mental activity supervenes on computational
> activity.

I agree. Consciousness is attached to computation (and not to
computational states), even at the starting of the reasoning, and also
when the physical supervenience is introduced in MGA for the reductio
ad absurdum.
Then, eventually, keeping CTM, and thus abandoning (weak) materialism,
consciousness is related to, well not just a computation, but to an
infinite sheaves of computations. Consciousness is a first person
notion, and as such, is dependent on the first person uncertainty
measure brought by the first person indeterminacy.
This is why I take time to explain what is a computation, or a
computational activity, in purely arithmetical terms. A computation is
not "just" a sequence of computational states, it is a sequence of
computational states related by at least one universal machine (and
then an infinity of them, from the point of view of the conscious
being, observably so when he/she looks below its substitution level).
Classical physics become the study of our most probable computations,
which emerge from the statistical interference of all computations
going through my relevant states (the relevance being dependent of the
observer's comp-substitution level).

>> Thanks for quoting my sane2004 definition of comp, and showing that
>> indeed platonism is not part of it.
> "It is a version of Platonism"

The wording is not important. The point is that in the assumption of
CTM, (CT+ the theological act of faith), I am using that "version of
platonism" only, which is just the idea that classical logic can be
applied to arithmetical sentences, and in the conclusion, only, we
have to abandon weak materialism or CTM.

>> Just arithmetical realism without which CT has no meaning at all.
> The CT thesis requires some mathematical
> claims to be true. it doesn't require numbers to actually exist

I have never asserted that numbers actually exist. Just that they
exist in the sense of the usual interpretation of existential
arithmetical statement are independent of me, you, or the existence or
not of a material world.

Would the two cosmic branes never have collided, and the big bang
never occurred, the Rieman hypothesis would still be atemporally and
aspatially true or false.

>> Get the feeling you have change your mind on AR. You believe that a
>> proposition like the statement that there is no biggest prime number
>> has something to do with physics. In which physical theory you prove
>> that statement, and how?
> Its truth is not a physical truth. The existence or non-existence
> asserted is not any kind of real existence

OK, in your theory "real existence" = "physical existence". But if the
UDA is valid it would be better to write "consensual reality" =
"physical reality", and ontic or basic 3- existence = arithmetical
existence, or to abandon CTM. If UDA is non valid, it would be nice to
point where is the error. You said that the error is in step 0,
because I would have pretended something like "the number seven
actually exists". My answer is that I don't see where I say so. I just
say that the number seven exists, in the sense used by mathematicians.
I limit my "platonism" to arithmetic to avoid the problem of
"platonism" in set theory or analysis, and the CTM explains why
realism on natural numbers in both necessary and sufficient.

> I am not denying nay truths, only the interpretation of backwards-E
> as actual existence

I am using a fairly common notion of mathematical existence, and I
explain that once you say yes to the doctor, the notion of physical
existence has to be reduced to that common notion of mathematical
existence (actually a tiny part of arithmetical existence).

Up to now, the only things you criticize in the UD reasoning are
things *you* are introducing, and when I remark to you that it is not
there, you say, it is implicit, but fail to show me where those
implicit statement have been used. Then you change the meaning of
"platonism" at every post. You define a criterium of "real" (RITSIAR)
without ever saying if the "I" is the third person body (which we can
doubt the existence) or the first person consciousness (which we
cannot doubt, but can't communicate). You said that the difference is
epistemological, but that does not answer the question.
You said once that you accept mathematical truth, and then that the
number seven does not exist AT ALL.
You compare mathematical object with fictional character in fairy
tales! Do you really think that an arithmetician could write "Once
upon a time there was an odd number dreaming becoming an even
number ...".

It would help much more if you were able to say "I don't understand
this or that in the reasoning, and give explicit reference to the
paper or posts".

I would be pleased if you could stop to attribute me more than I make
explicit. Comp is perhaps just a more precise and much more weak
assumption than usual CTM theory which usually put the comp level very
high. Comp is a weak precise form of CTM. And yes, I do believe that 02
+ 2 = 4, and that 07 is prime.


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Received on Fri Aug 21 2009 - 21:49:06 PDT

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