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Science Forum Index » Logic Forum » Newberry's Theses
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| Aatu Koskensilta |
Posted: Thu Apr 24, 2008 2:32 am |
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On 2008-04-23, in sci.logic, Newberry wrote:
Quote: How did your mind came to apprehend this from your understanding of
the naturals? Do you believe in Church's thesis?
How is Church's thesis relevant to my understanding of the naturals?
As to how I come to understand the naturals I have nothing very
interesting to say. My understanding is the same sort as any person
has of anything, and it's a matter of psychology and other such
empirical fields of investigations what the details of my coming to
this or that are.
--
Aatu Koskensilta (aatu.koskensilta@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Aatu Koskensilta |
Posted: Thu Apr 24, 2008 2:36 am |
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On 2008-04-23, in sci.logic, Newberry wrote:
Quote: Indeed not everything is provable in PA. So how come we are absolutely
certain that PA is consistent? How can there be certainty without a
proof? If we can be certain about a mathematical truth without a
proof, what are the proofs for?
We have any number of perfectly good proofs of the consistency of
PA. All of these necessarily involve mathematical principles not
contained in PA.
Your questions are, as Daryl notes, interesting, in the general
philosophical sort of way, but not in any way connected to any notion
about the paradoxical nature of Godel's results.
--
Aatu Koskensilta (aatu.koskensilta@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Aatu Koskensilta |
Posted: Thu Apr 24, 2008 2:47 am |
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On 2008-04-23, in sci.logic, Newberry wrote:
Quote: No, but I am asking you how you know that it cannot?
It's mathematically provable that no contradiction is provable from
true premises. That is, whenever we can give a truth definition for
some language, we can prove that whatever is provable from true
premises is true and no contradiction is true.
Quote: I am asking if those manifest truths are analytic, synthetic a priori,
or synthetic a posteriori?
I've no idea. Do you think these questions are relevant to your idea
that there's something paradoxical about Godel's results?
Quote: And you still need a proof of consistency to make sure your
formalization of the meaning of the terms is correct.
No proof of consistency needs be involved in verifying that these or
those formal sentences are correct formalisations of these or those
mathematical claims or notions. On this see my post /Formalisation/
available on-line at
http://groups.google.com/group/sci.logic/msg/1cf3026be617d644
(Message-ID: <slrnf6am4g.q15.aatu.koskensilta@localhost.localdomain>)
Quote: So if you you somehow arrived at the conclusion that the axioms are
consistent, and at the same time you proved that consistency is
unprovable you need to explain how exactly you arrived at the
conclusion that they are consistent.
There is no tension between showing that something is formally
unprovable in this or that formal theory and our being able to prove
that something. Why do you think there is?
--
Aatu Koskensilta (aatu.koskensilta@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Aatu Koskensilta |
Posted: Thu Apr 24, 2008 2:50 am |
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On 2008-04-23, in sci.logic, Daryl McCullough wrote:
Quote: Could you please try to understand what Godel's theorem says,
before you start making grandiose claims about what it means?
Why should we try to rob people of their sense of the wonderful? It's
much easier to find all sorts of great stuff in Godel's result when
one has no idea of their actual mathematical content.
--
Aatu Koskensilta (aatu.koskensilta@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Newberry |
Posted: Thu Apr 24, 2008 4:01 am |
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On Apr 24, 4:35 am, Aatu Koskensilta <aatu.koskensi...@xortec.fi>
wrote:
Quote: On 2008-04-24, in sci.logic, Jesse F. Hughes wrote:
As far as I recall, Russell didn't claim that the axioms of
mathematics are analytic, but rather that statements of the form
"The axioms entail P" are analytic. Thus, the question I asked
about choice just doesn't come up.
Russell certainly thought that the basic axioms of mathematics should
be reduced to purely logical principles. It was because he saw no way
of justifying the axiom of infinity and the multiplicative axiom as
logical truths he considered the project of Principia Mathematic as
having failed.
The axiom of infinity is admittedly synthetic a priori but this fact
is irrelevant. It merely constructs the universe of discourse. All the
statements about the universe of discourse are analytic. (What I mean
by infinity is that you can always add one not that there actually
somehow exist infinitely many of something. Infinite = never
finished.)
You do not need the axiom of infinity. You can pick a very large
number e.g. 2^128^128 and postulate its existence. The very fact that
you wrote it down proves that it exists. The postulate is synthetic a
posteriori. No practical mathematics will change. Yoy will still have
to do proofs by induction because the search space is too large. And
if you think the number is not large enough I will give you a lot
bigger one. |
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| Newberry |
Posted: Thu Apr 24, 2008 4:04 am |
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On Apr 24, 12:36 am, Aatu Koskensilta <aatu.koskensi...@xortec.fi>
wrote:
Quote: On 2008-04-23, in sci.logic, Newberry wrote:
Indeed not everything is provable in PA. So how come we are absolutely
certain that PA is consistent? How can there be certainty without a
proof? If we can be certain about a mathematical truth without a
proof, what are the proofs for?
We have any number of perfectly good proofs of the consistency of
PA. All of these necessarily involve mathematical principles not
contained in PA.
There is a contradiction right here. "perfectly good proof" and
"involve mathematical principles not contained in PA."
Quote: Your questions are, as Daryl notes, interesting, in the general
philosophical sort of way, but not in any way connected to any notion
about the paradoxical nature of Godel's results.
--
Aatu Koskensilta (aatu.koskensi...@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Newberry |
Posted: Thu Apr 24, 2008 5:18 am |
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On Apr 24, 7:36 am, stevendaryl3...@yahoo.com (Daryl McCullough)
wrote:
Quote: Newberry says...
On Apr 23, 7:24=A0am, stevendaryl3...@yahoo.com (Daryl McCullough)
wrote:
Newberry says...
Probably the simplest way to put is this: We are certain that PA is
consistent. We also know that we cannot prove it.
It's not that *we* can't prove it. Godel's theorem shows that
*PA* can't prove it.
No we cannot prove.
If you say so, but that's not what Godel's theorem says.
I did not say that Goedel's theorem says that we cannot prove it. I
said we cannot prove it. But we utilize Goedel's theorem in the
argument showing that we cannot prove it. Therefore Goedel's result is
paradoxical.
Quote: So your comments are not relevant to the issue of whether
Godel's theorem is paradoxical.
--
Daryl McCullough
Ithaca, NY |
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| Jesse F. Hughes |
Posted: Thu Apr 24, 2008 6:20 am |
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Newberry <newberryxy@gmail.com> writes:
Quote: On Apr 23, 7:36 pm, "Jesse F. Hughes" <je...@phiwumbda.org> wrote:
All the theories that Newberry says are mathematics are analytically
true (aside from geometry). We know they are analytically true
because Newberry says so.
Obviously, I have no reservations about that thesis.
Also Hume, Frege and Russell said it but that is not the reason that
mathematics is analytic.
As far as I recall, Russell didn't claim that the axioms of
mathematics are analytic, but rather that statements of the form "The
axioms entail P" are analytic. Thus, the question I asked about
choice just doesn't come up.
I could be wrong about Russell, of course.
Quote: In any case the idea that mathematics is Platonic is pretty
incredible. Even if Goedel's result is not paradoxical it leads to
this extraordinary conclusion, which is a good enough reason to
reform PA.
I have no idea why you think this (or, indeed, what it means).
I also haven't seen you actually argue that mathematics *is* analytic
yet, by the way. You just proclaimed it so and then refined the
claim so that all the really good (i.e., acceptable to Newberry)
mathematics is analytic.
--
Jesse F. Hughes
"Wiles made somewhere around half a million dollars U.S. that I heard
about, and I know he didn't take major endorsements."
--JSH on the rewards of proving Fermat's last theorem. |
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| Aatu Koskensilta |
Posted: Thu Apr 24, 2008 6:35 am |
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On 2008-04-24, in sci.logic, Jesse F. Hughes wrote:
Quote: As far as I recall, Russell didn't claim that the axioms of
mathematics are analytic, but rather that statements of the form
"The axioms entail P" are analytic. Thus, the question I asked
about choice just doesn't come up.
Russell certainly thought that the basic axioms of mathematics should
be reduced to purely logical principles. It was because he saw no way
of justifying the axiom of infinity and the multiplicative axiom as
logical truths he considered the project of Principia Mathematic as
having failed.
--
Aatu Koskensilta (aatu.koskensilta@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Jesse F. Hughes |
Posted: Thu Apr 24, 2008 6:41 am |
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Aatu Koskensilta <aatu.koskensilta@xortec.fi> writes:
Quote: On 2008-04-24, in sci.logic, Jesse F. Hughes wrote:
As far as I recall, Russell didn't claim that the axioms of
mathematics are analytic, but rather that statements of the form
"The axioms entail P" are analytic. Thus, the question I asked
about choice just doesn't come up.
Russell certainly thought that the basic axioms of mathematics should
be reduced to purely logical principles. It was because he saw no way
of justifying the axiom of infinity and the multiplicative axiom as
logical truths he considered the project of Principia Mathematic as
having failed.
Thanks for the correction.
--
Jesse F. Hughes
"This Trojan appears to utilize a function of the Windows Media DRM
designed to enable license delivery scenarios as part of a social
engineering attack." -- MS candidly explains the role of DRM licenses |
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| Aatu Koskensilta |
Posted: Thu Apr 24, 2008 9:07 am |
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On 2008-04-24, in sci.logic, Newberry wrote:
Quote: There is a contradiction right here. "perfectly good proof" and
"involve mathematical principles not contained in PA."
It appears then that it's your position that no mathematical proof is
acceptable if it involves mathematical principles not contained in
PA. On that position the consistency of PA is not provable -- and
there's no contradiction involved whatsoever in Godel's results --,
but what reason is there to adopting this curious idea?
--
Aatu Koskensilta (aatu.koskensilta@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Daryl McCullough |
Posted: Thu Apr 24, 2008 9:36 am |
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Newberry says...
Quote: On Apr 23, 7:24=A0am, stevendaryl3...@yahoo.com (Daryl McCullough)
wrote:
Newberry says...
Probably the simplest way to put is this: We are certain that PA is
consistent. We also know that we cannot prove it.
It's not that *we* can't prove it. Godel's theorem shows that
*PA* can't prove it.
No we cannot prove.
If you say so, but that's not what Godel's theorem says.
So your comments are not relevant to the issue of whether
Godel's theorem is paradoxical.
--
Daryl McCullough
Ithaca, NY |
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| Daryl McCullough |
Posted: Thu Apr 24, 2008 10:11 am |
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Newberry says...
Quote: On Apr 24, 12:36=A0am, Aatu Koskensilta <aatu.koskensi...@xortec.fi
wrote:
We have any number of perfectly good proofs of the consistency of
PA. All of these necessarily involve mathematical principles not
contained in PA.
There is a contradiction right here. "perfectly good proof" and
"involve mathematical principles not contained in PA."
No, it is not a contradiction. Look, you bring up interesting
questions about the nature of "certainty" in mathematics:
Is something certain because it is proved? Only if we consider
the axioms to be certain. But how do we come to be certain of
the axioms? Etc.
Interesting questions. But they are not what Godel's theorem
is about. Godel's theorem is not about any *absolute* notion
of mathematical certainty, it's about a very specific subject:
Mathematical proof from a set of axioms. "Certainty" may be
fuzzy, but "proof" is not. We either have a proof from a set
of axioms, or we don't. We can mechanically check that a
purported proof actually is a proof. Godel's theorem is about
this narrowly defined topic. It's not about the open-ended,
fuzzy topic of the nature of mathematical certainty. So
your comments don't have anything to do with the issue
of whether there is something paradoxical about Godel's theorem.
--
Daryl McCullough
Ithaca, NY |
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| Aatu Koskensilta |
Posted: Thu Apr 24, 2008 10:24 am |
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On 2008-04-24, in sci.logic, Newberry wrote:
Quote: But we utilize Goedel's theorem in the argument showing that we
cannot prove it.
How do we utilise Godel's theorem to show that we can't prove PA
consistent?
--
Aatu Koskensilta (aatu.koskensilta@xortec.fi)
"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus |
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| Daryl McCullough |
Posted: Thu Apr 24, 2008 10:49 am |
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Newberry says...
Quote:
On Apr 24, 7:36=A0am, stevendaryl3...@yahoo.com (Daryl McCullough)
wrote:
Newberry says...
On Apr 23, 7:24=3DA0am, stevendaryl3...@yahoo.com (Daryl McCullough)
wrote:
Newberry says...
Probably the simplest way to put is this: We are certain that PA is
consistent. We also know that we cannot prove it.
It's not that *we* can't prove it. Godel's theorem shows that
*PA* can't prove it.
No we cannot prove.
If you say so, but that's not what Godel's theorem says.
I did not say that Goedel's theorem says that we cannot prove it. I
said we cannot prove it. But we utilize Goedel's theorem in the
argument showing that we cannot prove it.
No, we don't. Nobody besides you claims that we can't prove
the consistency of PA.
Quote: Therefore Goedel's result is paradoxical.
No, it's not. Look, you think something is paradoxical,
but it isn't Godel's theorem. If you want a paradox, here's
one: Many people are convinced that Godel's theorem is
paradoxical, even though it's not.
--
Daryl McCullough
Ithaca, NY |
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