On 23 Mar 2015, at 04:55, Kim Jones wrote:
On 23 Mar 2015, at 10:19 am, meekerdb <[email protected]> wrote:
On 3/22/2015 2:45 PM, LizR wrote:
On 23 March 2015 at 07:37, meekerdb <[email protected]> wrote:
I don't think step 3 is at all essential to the argument. It's
nothing but setting up an analogy to Everett's MWI to show how
uncertainty and determinism are compatible - all of which JKC
already accepts.
I have put this point to him, but he says something like "because
we can never see the consequences of the MWI split, but we could
see the result of a teleporter duplication, therefore it's
different" (that seems like the gist of the argument, at least).
Bruno's point of course is just that if we had the teleporter, it
would lead to indeterminacy, just as MWI splits do (indeed, if we
take Everett literally, ISTM the MWI is an instance of Bruno's
teleporter) - whether or not we can talk to our duplicate later is
irrelevant to the point of the argument.
ISTM that the flaws in comp, if they exist, are either (a) at the
start - the premises are flawed (e.g. assumptions about the
ontological status of Peano arithmetic), or (b) at the end - the
MGA / "reversal" stage. The intermediate steps follow fairly
straightforwardly from the premises (if they are assumed correct).
Those are my reservations too: Not only the ontological status of
arithmetic (or other computational systems) but also of the UDA.
Some of the inferences, like Godel incompleteness, depend on
infinities, which I think is just a convenience. Some of the modal
inferences appear to depend on ex falso quodlibet, which again is
just a convenient simplification of valid inference. On the other,
MGA end, I suspect that it's necessary to emulate a whole "world",
in which case the conclusion is close to trivial. I also wonder
about some of modal axioms; aren't there equally intuitive
alternatives?
So we're still at the point where John claims to have spotted a
flaw, but he can't satisfactorily explain it to anyone else.
I think I understand the "flaw". When the thought experiment is
posed with the pronoun you: "You are in Helsinki. You are
duplicated so your duplicates appear in Moscow and Washington.
Then you will be uncertain as to which city you will find yourself
in." then it appears unanswerable and ill posed because "you" is
ill defined in the presence of duplicating machines. There is no
theory of personal identity in the premises, it just tries to rely
on the intuitions built into language, which assume persons aren't
duplicated. If the thought experiment started with, "Suppose *you*
are a unique, unreproducible immaterial soul..." then it might have
an answer.
On the other hand if pronouns are avoided, so that referents are
clear: "John is in Helsinki. John is duplicated so duplicate Johns
appear in Moscow and Washington. Then John will be uncertain as
to which city John will find himself in." then the ambiguity is
clear in that the second occurrence of 'John' could refer to Moscow-
John or Washington-John and if you make it explicit it's no longer
true, e.g. "Then Helsinki-John will be uncertain as to which city
Moscow-John will find himself in."
But Bruno is only explicating how there can be an objectively
determinsitic process that *necessarily* produces a subjectively
uncertain outcome.
Yes. Clark has to accept the necessary nature of FPI to be in
aosition to go on. Understanding step 3 entails understanding that
the FPI is purest indeterminacy at the heart of a deterministic
universe. He never will. That's where he's scared. It's too much for
him to suppose that some things are truly random.
Are you sure? Clark seems to defend the existence of events without
cause. He uses also the "truly random" notion to argue (correctly)
against a certain type of strong notion of free-will.
(of course I don't follow him in inferring that all notion of free-
will is uninteresting)
I am not sure he has any problem other than with himself.
No amount of additional information will remove the subjective
uncertainty of Helsinki-John about his future. JKC says this is
trivial since subjective uncertainty about the future is
commonplace. But it's not trivial, anymore than Everett's MWI is
trivial, because without the duplication of subjects, subjective
uncertainty about a deterministic process could always be
eliminated by gaining more information.
JKC is just picking on the fact that Moscow-John could meet
Washington-John to say that this is different that Everett's MWI.
But when an argument uses a thought experiment it is always the
case that the thought experiment is different from reality in some
respect. In this case that difference is irrelevant to the
inference from the thought experiment, so there's no reason to
object to it. That's why it is a mistake to reject and argument as
soon as you find a "flaw" in one step. It is necessary to see that
the "flaw" is used in later steps before you can reject the argument.
Brent
Very well explained, indeed.
Agreed.
Now, wouldn't it be wonderful if JKC were to read and accept the
situation as you have outlined so he could then move on (presumably
to find some "flaw" in step 4...)
I predict he won't. The whole thing has been a linguistic/semantic
side-issue.
Those who understand the math will see the argument clearly. Bruno
beavers away regularly at that because he knows that words are
highly limited and fallible tools. As I will never tire of saying,
verbal language is not designed to cope with notions of a plural
reality. This is new knowledge which actually sits between many
fields so it has this surprising feature of Language freezes
meanings into words and phrases at a relative state of ignorance and
lugs those meanings around forever.
OK, but people are also unaware that logicians have made tremendous
progress in metamathematics-alias "mathematical logic", so we can talk
on things non provable by this or that machine, and that some notion
are not definable by the machine (like a notion of truth encompassing
them), etc.
The problem is that there are few people serious in logic, in QM and
in "philosophy of mind".
And defamation does not help especially in interdisciplinary field.
Bruno
http://iridia.ulb.ac.be/~marchal/
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