On 29 Mar 2015, at 21:25, meekerdb wrote:
On 3/29/2015 1:33 AM, Quentin Anciaux wrote:
Le 29 mars 2015 09:03, "Bruce Kellett" <bhkell...@optusnet.com.au>
a écrit :
>
> meekerdb wrote:
>>
>> On 3/28/2015 11:54 PM, Bruce Kellett wrote:
>>>
>>> meekerdb wrote:
>>>>
>>>> On 3/28/2015 11:02 PM, Bruce Kellett wrote:
>>>>>
>>>>> meekerdb wrote:
>>>>>
>>>>> The calculation written out on paper is a static thing, but
the result of that calculation might still be part of a simulation
that produces consciousness. Though, unless Barbour is right and
the actuality of time can be statically encoded in his 'time
capsules (current memories of past instances)', I was thinking in
terms of a sequence of these states (however calculated).
>>>>
>>>>
>>>> Yes, I agree that the computation should not have to halt
(compute a function) in order to instantiate consciousness; it can
just be a sequence of states. Written out on paper it can be a
sequence of states ordered by position on the paper. But that
seems absurd, unless you think of it as consciousness in the
context of a world that is also written out on the paper, such that
the writing that is conscious is /*conscious of*/ this written out
world.
>>>
>>>
>>> My present conscious state includes visual, auditory and
tactile inputs -- these are part of the simulation. But they
need simulate only the effect on my brain states during that moment
-- they do not have to simulate the entire world that gave rise to
these inputs. The recreated conscuious state is not
counterfactually accurate in this respect, but so what? I am
reproducing a few conscious moments, not a fully functional person.
>>
>>
>> But isn't it the case that your brain evolved/learned to
interpret and be conscious of these stimuli only because it exists
in the context of this world?
>
>
> Yes.
>
>
>
>>>> But in the MGA (or Olympia) we are asked to consider a device
which is a conscious AI and then we are led to suppose a radically
broken version of it works even though it is reduced to playing
back a record of its processes. I think the playback of the record
fails to produce consciousness because it is not counterfactually
correct and hence is not actually realizing the states of the AI -
those states essentially include that some branches were not taken.
Maudlin's invention of Klara is intended to overcome this objection
and provide a counterfactually correct but physically inert
sequence of states. But I think it Maudlin underestimates the
problem of context and the additions necessary for counterfactual
correctness will extend far beyond "the brain" and entail a
"world". These additions come for free when we say "Yes" to the
doctor replacing part of our brain because the rest of the world
that gave us context is still there. The doctor doesn't remove it.
>>>
>>>
>>> In the "yes doctor" scenario as reported by Russell, it talks
only about replacing your brain with an AI program on a computer.
It does not mention connecting this to sense organs capable of
reproducing all the inputs one normally gets from the world. If
this is not clearly specified, I would certainly say 'No' to the
doctor. There is little point or future in being a functioning
brain without external inputs. As I recall sensory deprivation
experiments, subjects rapidly subside into a meaningless cycle of
states -- or go mad -- in the absence of sensory stimulation.
>>
>>
>> The question as posed by Bruno, is whether you will say yes to
the doctor replacing part of your brain with a digital device that
has the connections to the rest of your brain/body and which
implements the same input/output function for those connections.
Would that leave your consciousness unchanged?
>
>
> OK. If all the connections and inputs remain intact, and the
digital simulation is accurate, I don't see a problem. But I might
object if the doctor plans to replace my brain with an abstract
computation in Platonia -- because I don't know what such a thing
might be, and don't believe it actually exists absent some physical
instantiation.
>
> As you see, I believe in physicalism, not in Platonia. And I have
not yet seen any argument that might lead me to change my mind.
Then as a MGA shows that computations do not supervene in realtime
on the physical, then as a physicalist you simply have to
reject computationalism as a theory of mind.
The thing is no one is giving arguments to believe one or
another... Bruno did only show both assumptions cannot be true at
the same time, he chose to keep for the sake of the theory and find
where that leads and how it could solve the mind body problem.
Never he asserts computationalism is true or that physicalism is
false. Feel free to pursue on the possibility that physicalism is
true (or a complete other theory) to resolve that same problem.
But if you stay in the physicalist contest you can't use
computations to explain consciousness and that's what maudlin klara/
olympia and MGA thought experiments shows.
But I don't agree that they show that, or more accurately I think
they show that physicalism requires the context of a physical
world. Bruno will say, with some justification, that "physical"
isn't defined. But that's because he's a Platonist and assumes
definitions must be axiomatic. I think ostensive definitions are
more useful - at least for defining "physical".
Ironically, I agree with you.
Indeed, I *define*, *axiomatically* the *physical* by the ostensive
mode.
The ostensive itself is defined like all indexicals, that is, by the
use of the second recursion theorem of Kleene, which I simplify
sometimes by the little "song" if Dx gives T(xx), then DD gives T(DD).
T(x) = "x points to the moon", so you can take Dx = (xx points to the
moon) and DD = (DD points to the moon).
DD believes this defines the moon, but DD omits to see that this
defines only the moon he is pointing too. It makes the moon existing
physically, but "physical" remains a mode of the universal machine/
observers.
Eventually, it is this type of analysis which leads to define
observable with the indexical []p & <>t, with p sigma_1 (DU-accessible).
No need of physicalism for this. But we need to show that this makes
higher the measure on the relative physical observable. The nice first
step already done is to show that the logic of [2]p = []p & <>t gives
some reasonable quantum logical quantization.
By a result by Goldblatt, you get it if you have [2]A -> A, and p ->
[2]<2>p on enough proposition p, and some other things. And we get
them indeed, on p sigma_1 true, ... except the necessitation rule,
and, ... well, that might be a problem for classical computationalism,
but up to now we get the right quantum tautologies.
Sorry if I am too much technical. hope you remember enough bit of what
I said about modal logic, but you need to grasp more on self-reference
logic, which imposes one clear modal logics in which you can define
the different points of view.
I often agree with you, but, like with Craig, not as you would give an
argument against the fact that comp implies immaterialism, but more as
you make a valid point on the physical mode.
Another point: I don't use axiomatic because I would be a platonist, I
use axiomatic because it is a way to avoid any metaphysical baggage,
be it physicalist-aristotelian, immaterialist-platonist, ...
Bruno
http://iridia.ulb.ac.be/~marchal/
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
