On 22 Aug, 08:21, Bruno Marchal <marc...@ulb.ac.be> wrote:
> On 21 Aug 2009, at 10:28, Flammarion wrote:
> > 1. Something that ontologically exists can only be caused or generated
> > by something else that does
> > 2. I ontologically exist
> > 3. According to you, I am generated by the UD
> > 4. Therefore the UD must ontologically exist.
> > Step 4 is really step 0 which I have worked backwards
> > to here
> 5. But the UD exists only mathematically.
> Thus, ontological existence = mathematical existence.
> > There is no usual one, since there is no one agreed ontology
> > of mathematics.
> For sets and functions, you may be right. For numbers, there is a
> general mathematical agreement.
No there isn't.
>There may be no philosophical
> argument, but this is not relevant to undersatnd the non philosophical
Ontology is philosophy. You can't settle ontological quesitons
with mathematical proofs.
> > You are aware. are you not, that philosophers
> > and mathematicians are still writing books and papers attacking
> > and defending Platonism and other approaches?
> Platonism is used by both philosopher and mathematician as something
> far more general than arithmetical realism, on which all
> mathematicians agree.
I am not concerned with argument about how many pixies exist.
The point remains: there *is* a debate so there is *not* a standard
>It is believed explcitly by many physicists too,
> like David Deutsch, Roger Penrose, and those who use math in physics.
I never said no-on beliieves Platonism. I said some
people belive other things. Therefore it is contentious,
therefore it is needs jsutification.
> >> By comp, the ontic
> >> theory of everything is shown to be any theory in which I can
> >> represent the computable function. The very weak Robinson Arithmetic
> >> is already enough.
> > I am not interested in haggling over which pixies exist.
> This may be the root of your problem.
> >> comp = CTM.
> > It clearly isn't by the defintiion you gave in
> > your SANE paper.
> All right. As I said: comp is CTM + "2 + 2 = 4".
Nope, mere truth does not buy the immaterial existence of a UD
> > Classical logic is just a formal rule.
> It depends on the realm in which you apply classical logic. In
> computer science people admit that a running program will either halt,
> or not halt, even in case we don't know. This is a non formal use of
> classical logic.
It still does not demonstrate the immaterial existence of computers
no-one has built.
> > Bivalence is not Platonism
> Exactly. This is one more reason to distinguish carefully
> "arithmetical realism" (bivalence in the realm of numbers), and
> Platonism (something huge in philosophy and theology).
Even more reason to distinguish between AR qua truth and AR qua
> > So what? If I am material the reasoning is correct. Since the
> > alternatives
> > to my being material are inherently unlikely, my reasoning is still
> > *probably* correct.
> You are telling me that if you are material, then you are material.
I am telling you I do not have to give equal weight to
> >> I begin to believe what Jesse and David says: you are dodging the
> >> issue.
> > What issue?
> CTM and weak materialism are epistemologically incompabible.
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