On Feb 6, 6:45 pm, Bruno Marchal <marc...@ulb.ac.be> wrote:
> On 06 Feb 2011, at 16:37, 1Z wrote:
> > On Feb 5, 7:43 pm, Bruno Marchal <marc...@ulb.ac.be> wrote:
> >> On 05 Feb 2011, at 14:14, 1Z wrote:
> >>> On Feb 4, 4:52 pm, Bruno Marchal <marc...@ulb.ac.be> wrote:
> >>>> On 04 Feb 2011, at 13:45, David Nyman wrote:
> >>>> I am saying that IF comp is true, then the laws of physics are
> >>>> derivable/emerging on the computations, in the limit defined by the
> >>>> first person indeterminacy.
> >>>> So, for someone who want comp false, it has to hope the 'observed
> >>>> physics' is different from the comp extracted physics.
> >>> They don't have to do that, because they can resist the conclusion
> >>> by
> >>> refuting AR (qua Platonism) or MGA
> >> Computationalism needs Church thesis which needs AR (Arithmetical
> >> Realism).
> > Nope, just AT (arithmetic truth).
> Actually, comp needs only, for the ontology, the quite tiny complete
> Sigma_1 truth.
As I have stated many times, it doesn;t matter in the least
how many or few immaterial objects you attribute existence to.
It's like saying pixies exist, but only a few
> Please don't put metaphysics where there is only
Believing in what is not proven is religion. I can
argue for anti realism.
> (saying yes to the admittedly betting doctor).
Saying yes to the doctor will not guarantee your
immaterial existence if there is no immaterial existence.
AR/Platonism is a separate assumption to yes Dr.
<And with comp,
> it is math, indeed, even (full, above Sigma_1 arithmetic.
> Arithmetical realism is what you need to apply the excluded middle in
> computer science and in arithmetic.
The excluded middle is a much of a formal rule as
anthing else. Formalists can apply it, so it is compatible
with anti realism.
>To understand the fundamental
> consequences of Church thesis you need to accept that some program
> computes function despite we have no means to know if it is total or
> partial, or that a program will stop or not.
And I can accept that by positing LEM as a formal rule. I don;t
have to posit an immaterial Plato's heaven
> Only ultrafinitist denies AR.
Wrong. Anti realists deny it. I have pointed this out many
times. You think the only debate is about the minimal
set of mathematical objects, and that is not the only debate. Anti
can accept a maximal set of objects, with the proviso that their
existence is fictive and not real existence
> AR+, the idea that we don't need more than AR, in this setting, is a
> consequence of the math. From 'outside' the tiny effective universal
> sigma_1 complete set is enough. from inside, even mathematicalism is
> not enough (it is more 'theologicalism').
> > The ontological status of
> > mathematical
> > objects is a area of contention in metaphysics, and not
> > straightforwardly
> > proven by mathematics itself.
> With comp, you don't need more than the part on which almost everybody
> agrees: arithmetical realism.
Anti realists do not agee on the real existence of any
part. There are no pixies at all, not just a few pixies.
>The engineers, the scientists, most
> Except for Thorgny Tholerus I never met an ultrafinitist. You don't
> have to decide if numbers are idea of the mind or sort of angel in
> Plato Heaven. With comp the very idea of number will itself be a
> number, a sort of second order number, relative to universes
> (universal numbers).
ULtrafinitism has nothing to do with it. For formalists
no number exists. They have no prejudice about any kind,
> >> And you cannot refute an argument by anticipating a refutation. So if
> >> you have a refutation of MGA you should present it.
> > See Colin Klein;s refutation of Maudlin's Olympia.
> We have already discussed this and Colin Klein does not touch the
> movie graph argument.
Then you had better stop saying the MGA and Olympia are equivalent
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