Re: UDA revisited and then some

From: Bruno Marchal <>
Date: Mon, 4 Dec 2006 12:45:20 +0100

Le 01-déc.-06, à 20:05, Brent Meeker a écrit :
> Bruno Marchal wrote:
>> Le 01-déc.-06, à 10:24, Stathis Papaioannou a écrit :
>>> Bruno Marchal writes:
>>>> <snip>
>>>>> We can assume that the structural difference makes a difference to
>>>>> consciousness but
>>>>> not external behaviour. For example, it may cause spectrum
>>>>> reversal.
>>>> Let us suppose you are right. This would mean that there is
>>>> substitution level such that the digital copy person would act AS IF
>>>> she has been duplicated at the correct level, but having or living a
>>>> (1-person) spectrum reversal.
>>>> Now what could that mean? Let us interview the copy and ask her the
>>>> color of the sky. Having the same external behavior as the original,
>>>> she will told us the usual answer: blue (I suppose a sunny day!).
>>>> So, apparently she is not 1-aware of that spectrum reversal. This
>>>> means
>>>> that from her 1-person point of view, there was no spectrum
>>>> reversal,
>>>> but obviously there is no 3-description of it either ....
>>>> So I am not sure your assertion make sense. I agree that if we take
>>>> an
>>>> incorrect substitution level, the copy could experience a spectrum
>>>> reversal, but then the person will complain to her doctor saying
>>>> something like "I have not been copied correctly", and will not pay
>>>> her
>>>> doctor bill (but this is a different external behaviour, ok?)
>>> I don't doubt that there is some substitution level that preserves
>>> 3rd
>>> person
>>> behaviour and 1st person experience, even if this turns out to mean
>>> copying
>>> a person to the same engineering tolerances as nature has specified
>>> for ordinary
>>> day to day life. The question is, is there some substitution level
>>> which preserves
>>> 3rd person behaviour but not 1st person experience? For example,
>>> suppose
>>> you carried around with you a device which monitored all your
>>> behaviour in great
>>> detail, created predictive models, compared its predictions with your
>>> actual
>>> behaviour, and continuously refined its models. Over time, this
>>> device
>>> might be
>>> able to mimic your behaviour closely enough such that it could take
>>> over control of
>>> your body from your brain and no-one would be able to tell that the
>>> substitution
>>> had occurred. I don't think it would be unreasonable to wonder
>>> whether
>>> this copy
>>> experiences the same thing when it looks at the sky and declares it
>>> to
>>> be blue as
>>> you do before the substitution.
>> Thanks for the precision.
>> It *is* as reasonable to ask such a question as it is reasonable to
>> ask
>> if tomorrow my first person experience will not indeed permute my blue
>> and orange qualia *including my memories of it* in such a way that my
>> 3-behavior will remain unchanged. In that case we are back to the
>> original spectrum reversal problem.
>> This is a reasonable question in the sense that the answer can be
>> shown
>> relatively (!) undecidable: it is not verifiable by any external
>> means,
>> nor by the first person itself. We could as well conclude that such a
>> change occurs each time the magnetic poles permute, or that it changes
>> at each season, etc.
>> *But* (curiously enough perhaps) such a change can be shown to be
>> guess-able by some richer machine.
>> The spectrum reversal question points on the gap between the 1 and 3
>> descriptions. With acomp your question should be addressable in the
>> terms of the modal logic Z and X, or more precisely Z1* minus Z1 and
>> X1* minus X1, that is their true but unprovable (and undecidable)
>> propositions. Note that the question makes no sense at all for the
>> "pure 1-person" because S4Grz1* minus S4Grz1 is empty.
>> So your question makes sense because at the level of the fourth and
>> fifth hypo your question can be translated into purely arithmetical
>> propositions, which although highly undecidable by the machine itself
>> can be decided by some richer machine.
>> And I would say, without doing the calculus which is rather complex,
>> that the answer could very well be positive indeed, but this remains
>> to
>> be proved. At least the unexpected nuances between computability,
>> provability, knowability, observability, perceivability (all redefined
>> by modal variant of G) gives plenty room for this, indeed.
>> Bruno
> So what does your calculus say about the experience of people who wear
> glasses which invert their field of vision?
This is just an adaptation process. If I remember people wearing those
glasses are aware of the inversion of their field of vision until their
brain generates an unconscious correction. All this can be explained
self-referentially in G without problem and even without mentioning the
qualia (which would need the Z* or X* ....). Stathis' remarks on the
existence of qualia changes without first person knowledge of the
change is far less obvious.
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Received on Mon Dec 04 2006 - 06:46:50 PST

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