--- On Fri, 3/5/10, Bruno Marchal <marc...@ulb.ac.be> wrote:
> It is a different fading qualia argument, older and different from Chlamers.
> It is explained in my PhD thesis, and earlier article, bur also in MGA3 on
> this list, and in a paper not yet submitted.
Bruno, do you have the link? I searched the list archive but the only
references to fading qualia I could find are to the argument I mentioned, in
which a brain is progressively substituted for by a movie, as Bishop does to
attack computationalism. It _is_ different than Chalmers, who substitutes
components that _do_ have the right counterfactuals - Chalmers' argument is a
defense of computationalism (albeit from a dualist point of view), not an
attack on it.
All of the 'fading qualia' arguments fail, for the reason I discussed in my PB
paper: consciousness could be partial, not faded. I am sure that yours is no
different in that regard.
> If consciousness supervenes on the physical realization of a computation,
> including the inactive part, it means you attach consciousness on an unknown
> physical phenomenon. It is a magical move which blurs the difficulty.
There is no new physics or magic involved in taking laws and counterfactuals
into account, obviously. So you seem to be just talking nonsense.
The only charitable interpretation of what you are saying that I can think of
is that, like Jesse Mazer, you don't think that details of situations that
don't occur could have any effect on consciousness. Did you follow the
'Factual Implications Conjecture' (FIC)? I do find it basically plausible, and
it's no problem for physicalism.
For example, suppose we have a pair of black boxes, A and B. The external
functioning of each box is simple: it takes a single bit as input, and as
output it gives a single bit which has the same value as the input bit. So
they are trivial gates. We can insert them into our computer with no problem.
Suppose that in the actual run, A comes into play, while B does not.
The thing about these boxes is, while their input-output relations are simple,
inside are very complex Rube Goldberg devices. If you study schematics of
these devices, it would be very hard to predict their functioning without
actually doing the experiments.
Now, if box A were to function differently, the physical activity in our
computer would have been different. But there is a chain of causality that
makes it work. If you reject the idea that such a system could play a role in
consciousness, I would characterize that as a variant of the well-known Chinese
Room argument. I don't agree that it's a problem.
It's harder to believe that the way in which box B functions could matter.
Since it didn't come into play, perhaps no one knows what it would have done.
That's why I agree that the FIC is plausible. However, in principle, there
would be no 'magic' involved even if the functioning of B did matter. It's a
part of the overall system, and the overall system implements the computation.
> If consciousness supervenes, in "real time and place" to a physical activity
> realizing a computation, and this "qua computatio" then consciousness
> supervenes on the movie (MGA2).
We already agreed that it _doesn't_ supervene on the activity alone. It
requires the counterfactuals too. I know you are trying to derive a
contradiction from physicalist computationalism, but you haven't done so.
> I see nothing nontrivial in your arguments.
> Nice! You agree with the argument then. Or what?
Huh? There is nothing of interest that is correct in your arguments, not
nothing false. And you knew that's what I meant.
> > Computations are implemented based on both activity and counterfactuals,
> > which is the same as saying they supervene on both.
> Then you have to provide a physical definition of what are activity,
> counterfactual and computation.
It's not phrased in terms of 'activity' - that's not a very useful term when
you look at details of systems - but all of the definitions that one needs for
computationalism are in my MCI paper. Counterfactuals, as I've already told
you, are defined in terms of physical laws: What would happen for each possible
state. What problem do you claim to see?
> But if those definitions leads to a Turing emulable process, you just lift
> the difficulty on another level.
As far as we know, physics is computable (although analog). So what? That
brings in no difficulty.
> Eventually you talk like if we knew which universal system supports us.
No, I don't and don't need to.
> Chalmers told me publicly, at a poster presentation in Brussels, that in the
> duplication Washington/Moscow, the first person feels be to at the two places
> at once. This is indeed coherent with his dualism. But this, together with
> comp, entails telepathy between the multiplied selves. He left the room when
> I made that remark.
Chalmers' dualist beliefs are not relevant to what we have been discussing - I
only mentioned him because he wrote the most widely cited paper on
implementation of computations - but I don't think he would agree that the
person would have any telepathic connection between the places even
epihenomenally. It seems more likely he meant something else, like that he
would define them both to be the same person even though they each feel like
they're the full original. That is especially likely given that he does favor
the MWI, which already involves similar splits and obviously no telepathy
between branches. My hypothesis is that you misunderstood him. I could be
wrong about him, I admit. I used to correspond with him, but not recently.
Many people consider him a big shot and maybe he let it go to his head.
> Now I agree with the mainstream computationalist that the 'right
> counterfactual' are needed. But I do not follow the "(aka the right
> 'physical' laws)". It is not computationalism, it is physicalism at the start.
Didn't you see the quotes around 'physical'? As should have been obvious, I use
it as short for "physical or Platonic". Really that's not important here. The
point is that MGA fails because it doesn't take the needs for the laws into
> > I have already done so (for MGA): You claim that taking counterfactuals
> > into account amounts to assuming 'prescience' and is thus implausible, but
> > that's NOT true. Using counterfactuals/laws is how computation is defined.
> OK. I see you have not get the point. MGA does not need the notion of
> counterfactuals. It just show that IF neurons, or basic entity have no
> prescience, then the movie has the same physical activity, as far as
> realizing a computation in real time, than the boolean graph. So, to *avoid*
> prescience, we have to make consciousness supervening on the counterfactuals.
> But those related to the computation are mathematical, immaterial, defined
> only in computer science. The physical counterfactuals have to be non
> relevant, or Turing emulable.
The above paragraph doesn't make any sense. Why do the physical
counterfactuals have to be non-relevant? Don't say "using them would involve
prescience"; I have already rejected that claim for which you provide no
justification. Any time you invoke the word "prescience" you just seem foolish
- physical counterfactuals are not prescience.
> > Your repeated claims that the error has not been pointed out are a standard
> > crackpot behavior.
> That would be the case if the work did not pass the academical test.
Sadly, some crackpots do get their work published and get people who should
know better to agree with them. The argument from authority holds no water
with me. Penrose is a crackpot, as is John Cramer, and none more so than Joy
Christian (who claims to have disproved Bell's theorem and got himself a nice
position at the Perimeter Institute).
> I am open that a systematic error may subsist,
So you say, but I doubt you are.
> but enough scientists (logicians, analytical philosophers, physicists, and
> many theoretical computer scientists) have take the (long) time to verify all
Who are these people? You are unable to explain yourself, so maybe it would be
better for me to correspond with someone more articulate. Who would you say is
best equipped to explain the "prescience" aspect of MGA among these other
people? I guess it should be one of the physicists, they are more likely to
talk in clear language.
> Only media and literary philosophers, and 2 pure mathematicians, keep on
> saying it is "crackpot", without any explanation (and behind my back).
I would also like to know who these people are. What media has discussed your
work? Also you have left me (a physicist) out; I have been saying it for years
here and to your virtual face.
> It is nice that you are open to the hypothesis, and open to the conclusion.
> But if you are agnostic on platonism, why do you invoke physicalness in the
> notion of computation to block the passage from the hypothesis to the
I don't. There is no motivation given for such a passage. Counterfactuals are
needed but they could be Platonic or physical.
> It seems that you contradict your own saying, your posts and your glossary. I
> already mentioned this, and you did not answer.
I did answer. As I already said in my post of 2/17/10:
>> It's true that I didn't mention Platonism in that glossary entry (in the MCI
>> paper), which was an oversight, but not a big deal given that the paper was
>> aimed at physicists.
> I prefer to tell you in advance that I may dismiss your next posts if they
> contain insults, swear words and/or rhetorical tricks.
What you may consider insults (and I can only guess) is nothing you have not
brought on yourself.
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