On 16 Aug, 16:34, Bruno Marchal <marc...@ulb.ac.be> wrote:
> On 14 Aug 2009, at 14:34, 1Z wrote:
> > On 14 Aug, 09:48, Bruno Marchal <marc...@ulb.ac.be> wrote:
> >> You are dismissing the first person indeterminacy. A stuffy TM can
> >> run
> >> a computation. But if a consciousness is attached to that
> >> computation,
> >> it is automatically attached to an infinity of immaterial and
> >> relative
> >> computations as well,
> > There's your Platonism.
> Not mine. The one which follows from the comp assumption, if UDA is
Without Platonism, there is no UD since it is not observable within
physical space. So the UDA is based on Plat., not the other way
> > If nothing immaterial exists (NB "nothing",
> > I don't make exceptions for just a few pixies or juse a few numbers)
> > there is nothiign for a cosnc. to attach itself to except a propbably
> > small, probabuily singular set of stuiffy brains and computers.
> I can understand how easy for a materialist it is, to conceive at
> first sight, that numbers and mathematical objects are convenient
> fiction realized as space-time material configuration, perhaps of
It's a perfectly consistent assumption. THere is no
disproof of materialism that doesn't beg the quesiton by
> But those space-time configuration are themselves described by
> mathematical functions far more complex that the numbers described or
Irrelevant. "Described by" does not mean "is"
>This leads to major difficulties, even before approaching the
> consciousness problem.
> This shows that a purely physicalist explanation of numbers could lead
> to difficulties. But the same for a description of any piece of
> material things, by just that token.
> So, I am not sure that physicist can be said to have solved the
> "matter" problem either,
You arguments here are based on the idea
that primary matter needs to be given a
purely mathematical expression. That in turn
is based on an assumption of Platonism. If
Platonism is false and materialism true,
one would *expect* mathematical explanation
to run out at some point. Your "difficulty" is a
*prediction* of materialism , and therefore a
> and some physicists are already open,
> independently of comp, to the idea that physical objects are relative
> mathematical (immaterial) objects. Which of course are "no material".
> Wheeler, Tegmark, for example.
They have a consisent set of assumptions. So do
their materialist oponents. You can't get an "is true"
out of a "might be true"
> But then with comp, you are yourself an immaterial object,
False. computaitonlism does not prove the immaterial existence
of anything whatsoever. Most computationalists are materialists.
>of the kind
> person, like the lobian machine. You own a body, or you borrow it to
> your neighborhood, and "you" as an immaterial pattern can become
> stable only by being multiplied in infinities of coherent similar
> histories, which eventually the physicists begin to talk about
> I tend to believe in many immaterial things. Some are absolutely real
> (I think) like the natural numbers.
There's your Platonism again. Believe what you like, but don'
call it proof.
> Some may be seen as absolutely real, or just as useful fiction: it
> changes nothing.
It changes everything. If the UD is a useful ficiton, I cannot be a
programme running on it, any more than I can book a flight to Narnia.
>This is the case for the negative number, the
> rational, a large part of the algebraic and topological, and analytical.
Look, I have already said that I am not going to get into an argument
about which pixies exist.
> Some are both absolutely real, and physically real, they live in
> "platonia", and then can come back on earth: they have a relatively
> concrete existence. For example, the games of chess, the computers,
> the animals, and the persons. But the concreteness is relative, the
> 'I' coupled with the chessboard is an abstract couple following
> normality conditions (that QM provides, but comp not yet).
> Some could have an even more trivial sense of absolute existence, and
> a case could be made they don't exist, even in Platonia, like the
> unicorns, perhaps, and the squared circles (hopefully).
> Each branch of math has its own notion of existence, and with comp, we
> have a lot choice, for the ontic part, but usually I take
> arithmetical existence, if only because this is taught in school, and
> its enough to justified the existence of the universal numbers, and
> either they dreams (if "yes doctor") or at least their discourse on
> their dreams (if you say no the doctor and decide to qualify those
> machines are "inexistent zombies").
> There is a sense to say those universal machines do not exist, but it
> happens that they don't have the cognitive abilities to know that, and
> for them, in-existence does not make sense.
If they don't exist, they don't exist. You don't have the
rigourous mathematical argument you think
you have, you have some baroque Chuang-Tzu metaphysics.
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To post to this group, send email to email@example.com
To unsubscribe from this group, send email to
For more options, visit this group at