Bruno Marchal wrote:
> On 04 Dec 2011, at 16:39, benjayk wrote:
>> Bruno Marchal wrote:
>>>> The steps rely on the substitution being "perfect", which they will
>>>> never
>>>> be.
>>> That would contradict the digital and correct level assumption.
>> No. Correctly functioning means "good enough to be working", not  
>> perfect.
> Once the level is chosen, it is perfect, by definition of digital.
> Either you miss something or you are playing with words.
No, you miss something. You choose to define the words so that they fit your
Wikipedia says "A digital system[1] is a data technology that uses discrete
(discontinuous) values.". That does not mean that digital system has no
other relevant parts that don't work with discrete values, and that may
matter in the substitution.
COMP does not say they can't matter.

Bruno Marchal wrote:
>> Digital means based on discrete values, not only consisting of  
>> discrete
>> values (otherwise there could be no digital computers, since they  
>> rely on
>> non-discrete functioning of their parts).
> In which theory. The assumptions are neutral on physics. Here, you are  
> not, so i suspect you work in some non defined theory.
What? We have to rely on some basic agreement of what the words used in the
argument mean, and this happens to be the agreement we use in our language
(digital means based on discrete values). This has little to do with a
specific theory.
If we don't presuppose any physics (even not in a practical sense), we can't
substitute a physical object (our brain), since "physical object" is
undefined, so COMP is meaningless, and in this case this is not a question
of lack of faith in the possbility of a correct substitution.
So if you want to eliminate any practical notion of physics in the
argumentation, you invalidate the COMP assumption, because it would state a
totally undefined thing (substituting a physical object).

Bruno Marchal wrote:
>> A digital
>> computer is not defined to be always working, and a correct  
>> substitution is
>> one where the computer works good enough, not perfectly.
> You miss the notion of level, and are splitting the hair, it seems to  
> me.
I am splitting the hair if I am pointing out the most essential flaw in the
I don't miss the notion of level. Correct substitution level means working
substitution level, nowhere does it say it works perfectly. Indeed it can't
work perfectly, as we all plainly observe in the physical world, no device
works perfectly.
You misrepresent the notion of level that is defined in the argument with
your imagination of what a level is supposed to be (the right level is the
perfect instantiation of the right turing emulable states).

It seems you just get defensive because you realize your argument doesn't
work. I see that it is important for you, but if you want to be honest, that
is no good reason to ignore criticism.

Bruno Marchal wrote:
>> And if you do
>> remain relatively invariant, it is only because you choose to define
>> yourself in a way that you are still yourself after a certain change  
>> in
>> experience, but that is just a matter of opinion, and it means that  
>> is just
>> a matter of opinion whether you survive a substitution - but then we  
>> can
>> only conclude that we may survive no substitution (if we don't  
>> believe YES
>> doctor) or we survive every substitution (!) or something inbetween  
>> - a
>> pretty weak conclusion.
> You are playing with words. Sorry, but I get that feeling. Comp would  
> have no sense if you were true here, and that contradict other  
> statement you made. you still are unclear if you criticize comp, or  
> the validity of the reasoning. You seem a bit wanting to be negative.
I am just being honest. My criticism can be conceived of a criticism of comp
or your reasoning, because I argue that either comp is false or the
So it might be that your reasoning cannot directly be shown false, if you
insist that COMP is meaningless.
You seem to do that above, as you want to eliminate all notions of
physicality, but then we can't substitute a physical brain anymore, so COMP
becomes meaningless.

Bruno Marchal wrote:
>> Also: How does your reasoning show that we can't survive every  
>> substitution?
> Nowhere the reasoning shows that. On the contrary, I have very often  
> presented the conclusion partially by saying: if you can survive (in  
> the usual clinical sense) with a concrete digital brain, then you will  
> survive no matter what.
OK. Then your argument refutes COMP. If I survive every substitution, there
can be no correct substitution level, and no non-abitrary description of my
parts. All levels would be correct and all descriptions correct, but that is
not only absurd, but also makes it impossible to choose the correct one.
But if COMP is false, your conclusion does not follow, obviously.

Bruno Marchal wrote:
>> but only *if done in the correct non-computational way*,
> And that would just contradict directly the comp *assumption*. You are  
> (again) shifting from a theory to another.
No. COMP does not state that only the computations matter. The doctor also
has to make the right artificial body, and you can't assume that only the
abstract computations involved matter in that.
If, for example, you substitute the brain with an artificial brain doing the
right computations, but too slowly, the patient won't survive as he used to.

Bruno Marchal wrote:
>> And since we know that the brain has do to
>> with emotions, is unreasonable that it strictly follows laws  
>> (including
>> comptutational laws).
> At all levels? Then comp is false.
No. We can still say YES because we believe that an approximate substitution
will still work.

Bruno Marchal wrote:
>> Unfortunately we live in a world of dogmatic scientism, materialism  
>> and
>> rationalism (but also in a world of irrationality and superstition and
>> dogmatic religion) and that's the only reason that many people  
>> assume those
>> things.
> Assuming clear hypothesis is good, if only to be shown wrong by nature  
> or by peer reviewers. You seem to argue against science. (As you often  
> did some time ago).
I am not against assuming these things as hypothesis, I am against not
taking any other possibility into account. 

Bruno Marchal wrote:
>> Bruno Marchal wrote:
>>>> It is even more obvious in step 3: "The description
>>>> encoded at Brussels after the reading-cutting process is just the
>>>> description of a state of some
>>>> Turing machine, giving  that we assume comp. So its description  
>>>> can be
>>>> duplicated, and  the
>>>> experiencer  can be  reconstituted  simultaneously  at two different
>>>> places,  for  example
>>>> Washington and Moscow". This assumes we work precisely like an
>>>> abstract
>>>> turing machine,
>>> Like a concrete Turing machine.
>> But a concrete Turing machine does not work like an abstract turing  
>> machine.
> It does. if that was not the case, the notion of substitution level  
> would have no sense.
Your argument is very clever. "My conclusion is true, because the notion
used in the assumption can make no sense other than the way I need it to be
to make the argument true". Prove that a substitution level makes no sense
if a concrete machine does not work like a turing machine.
Sure, the substitution level can not be absolute in that case, but that is
not required for the argument.

Bruno Marchal wrote:
>> but the computer is not
>> (and does not work) the same as the model. You confuse an actual thing
> Such a notion need a theory, which you have not given.
You don't precisely define all your notions in your argumentation as well
(define "faith" or "doctor" or "I" or "what I consider myself to be").
If your argument were valid, your argumentation would fail at the start.

This is just a bullshit argument. We can never precisely define everything
used in an argument. If you define everything in terms of numbers (I doubt
you can do that, but anyway), you will be unable to give a definition of
numbers (or 0), and according to your argument, all your argumentation would
be invalid.
It is enough that we can agree on the basic meaning of the terms, and it
shouldn't be too hard to *conceive* (only that is required) of a difference
of model and actuality.

Bruno Marchal wrote:
>> Bruno Marchal wrote:
>>> 1) Exact computational states or slightly changed one, after the
>>> recovering, are not relevant for the issue, and this is made clear at
>>> step seven, given that the robust universe running the concrete UD
>>> just goes through all those computational states, in all histories.
>>> The relevant points are only the first person indeterminacy, and its
>>> many invariance for some third person changes.
>> Step 7 does not even adress the issue that I am pointing at.
>> You write "With  comp, when  we  are  in  the  state  of  going  to  
>> drop
>> the  pen, we  are  in  a  Turing emulable  state. ". That's simply  
>> not the
>> assumption.
> ?
Well, where in the assumption is that statement made?

Bruno Marchal wrote:
>> COMP just says that a substitution with an (actual) computer can
>> work, not that the substitution works due to us being in a turing  
>> emulable
>> state -
> Of course it is. That is why I use often the expression "qua  
> computatio". It means I survive in virtue of the fact that the  
> relevant computation is physically implemented.
But the assumption does not say that this is the only requirement. Obviously
is also has to be *correctly* implemented.
Also, COMP does simply not state we are in a turing emulable state, it just
states that there is exists a description of my level that, if correctly
implemented, gives an acceptable result. Even if we take that description to
mean a description in terms of a "computational state", COMP doesn't say we
are in that state, just that we can be described by being in that state.
Just as a sky can be described to be cloudy, but the sky is prefectly
described by us stating that it is "cloudy".
You confuse description with state, apparently.

Bruno Marchal wrote:
>> it doesn't say why exactly the substition works (beyond being
>> functionally correct). We can say YES because we are emulable  
>> enough, *even
>> though* we are not in a precisely emulable state.
> We are exactly emulable at the substitution level.
Prove that, or show where in the COMP assumption this is stated.

Bruno Marchal wrote:
>> You can't presuppose that a substitution can only work if we are  
>> precisely
>> determined through a computational state.
> Of course.
You can presume this, but then your reasoning is dependent on this
additional assumption. COMP does not make it. Or show it.
You still haven't studied your assumption ;).

Bruno Marchal wrote:
>> You plainly miss all alternative conclusion that are not your  
>> conclusion or
>> commonly given alternatives.
> Which one (saving materialism)?
Immaterialist-"computations *can* be valid descriptions"ism.
We can be Immaterialist-"non-computationalist" and still be computationalist
in the sense of COMP (agreeing that our brain can be digitally substituted).
In this case we state that our brain can be described in terms of
computations, and this description can be used to build a computer to
substitute our brain, but our experience is not only related to the
computations going on, but also to the way it is instantiated.

Bruno Marchal wrote:
>> I am just not arguing at all for what
>> your argument(s) seeks to refute.
> I know that. It might be your problem. You have independent reason to  
> *believe* in the conclusion of comp. You just seems uncomfortable that  
> those conclusions can be extracted from comp. It looks like you feel  
> like this should force you to accept comp, but I have *never* say so.
The point is that I can conceive to say YES, at least in theory.
I am not uncomfortable that those conclusions can be extracted from comp,
they just can't. I pointed out your flaws in your argument over and over
again, and you simply avoid them by stating some assumption that you don't
make explicit in the reasoning (only the computational state can matter) and
then saying it is equivalent to COMP.

Bruno Marchal wrote:
>> (things are made of spatially defined and non-fuzzy
>> stuff, like bricks or something).
> Weak materialism is the statement that primitive matter exists  
> ontologically. It might be fuzzy, non local, even magical, etc.
If it is like that, what is the difference to immaterialism?
You didn't refute magical materialism, BTW. You 8 steps assumes nothing
magical is going on, and the MGA argument just refutes physical
supervenience (not physicality and consciousness are magically related).

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