On 30 Apr 2017, at 20:25, Brent Meeker wrote:
On 4/30/2017 4:39 AM, Stathis Papaioannou wrote:
On 26 April 2017 at 09:22, Brent Meeker <[email protected]> wrote:
On 4/25/2017 6:26 AM, Stathis Papaioannou wrote:
On Sun, 23 Apr 2017 at 5:58 am, John Clark <[email protected]>
wrote:
On Sat, Apr 22, 2017 Stathis Papaioannou <[email protected]>
wrote:
>> Suppose just for the sake of argument that
non-physical computations did not exist, how would our physical
world be different? There would be no difference. Therefore either
non-physical computations do not exist or they do but are
utterly
unimportant, rather like the l uminiferous aether .
> This is equivalent to supposing that mathematical
Platonism is false.
Not exactly. Einstein didn't prove the luminiferous
aether didn't exist in the Platonic sense, he just proved it
was unimportant. I suppose you could say in the vague way that
Greek philosophers love that correct mathematical calculations
exist independently of matter, but the trouble is incorrect
mathematical calculations exist too, and the only way to
differentiate the correct from the incorrect is by using matter
that obeys the laws of physics. And separating the stuff we want
from the stuff we don't is important, that's why we say
Michelangelo's huge statue of David is 500 years old and not far
older even though in the platonic sense David was inside a
gigantic block of Carrara marble for 100 million years and
all Michelangelo did was unpack it, he just removed the
parts of the block that weren't David.
But if the statue were conscious and it's consciousness not
dependent on interaction with the outside world, it would still be
conscious inside the marble block.
Any physical object could be viewed as implementing a computation
as anything could be mapped onto of a Turing machine, but the
"work" of the computation would then be not in the physical object
but in the mapping, a Platonic object. The problem with this is
that such an implementation cannot interact with its environment,
so you cannot, as you say to Bruno, use it to make money hiring
out your Platonic computer. But what if we consider conscious
computation that does not interact with the environment of its
implementation? Like the statue in the block of marble, it would
still be conscious even if no-one outside could appreciate it or
make money out of it.
I think this is specious. Even humans who, as in sensory
deprivation tanks, have no interaction with their environment tend
to "lose consciousness" in the sense of going into
though loops. If a brain were truly, completely isolated from it's
environment I think it very doubtful that it could remain
conscious. And if, like David in the block, had never experienced
an environment it would be hard to say what he could be conscious
OF. The computation in our brains takes it's "meaning" from our
interactions with the world.
When we are dreaming we are not aware of the external environment.
That's not true in the broad sense of "aware". Most people will
awake instantly if you whisper their name. Dreams often include
bits of the environment: the room is cold, there are noises
outside,... But my point was more general than that. If you had
never experienced the external world, like a newborn infant, your
brain would have to learn to conceptualize and your thoughts would
take their meaning from the external world and your interaction with
it. This is approximately what happens; although a new born is
actually given a head start by evolution providing some hardwired
concepts. Notice that on Bruno's theory the newborn should already
know logic and arithmetic - they are independent of the external
(physical) world.
In any case, the effect of sensory deprivation on humans is a
contingent fact about human psychology, and I don't think it
implies anything about the nature of consciousness in general.
I think it does. It's a bit of evidence supporting the theory that
consciousness evolved as part of intelligence in dealing with the
external world and any intelligent behaving being will be conscious
- i.e. will be able to predict and plan using internal simulations
in which the being itself is represented. So consciousness will
always be about something.
The question of where computations in our brains get their meaning
from is interesting. As we develop, certain brain patterns come to
be associated with certain patterns in the environment, and hence
acquire meaning. The brain pattern and associated meaning can later
be summoned in the absence of the environmental stimulus, as in a
thought or a dream. But if the same brain with the same brain
patterns were created de novo, say with an advanced 3D printer,
would the meaning be absent? I find it difficult to imagine how
that could be the case.
It depends on the relation of the brain pattern to the environmental
stimulus. "Created de novo" might mean occuring at random with no
relation to the referent except accident. If you think that
produces consciousness of the referent then you are led to the
paradox of the rock that thinks everything. That's why I think
there must be an interactive relation between consciousness and its
referent. Bruno denies this when he adopt Theaetatus's definition
of knowledge as true-belief. He reject Gettier's requirement that
to be knowledge there must be a causitive relation between the
belief and the thing believed - so just guessing correctly doesn't
count as knowledge.
The idea that computationalism implies that consciousness would
occur independently of physical activity has been used as an
argument against computationalism, on the grounds that it is self-
evidently absurd. Hilary Putnam, originator of functionalism (of
which computationalism is a subset), later realised this
implication and changed his mind. John Searle and Tim Maudlin came
to a similar conclusion.
But an alternative is, as Bruno suggests, to keep computationalism
and accept that the apparent physical world is secondary, not
primary. The physical computers sold
by Dell or IBM, along with everything else, are made in a virtual
reality running on a Platonic computer. While this may at first
glance seem absurd, there is no reason I can think of why it
cannot be true. And it has advantages in addition to preserving
computationalism, such as eliminating the need to explain why
there should be a physical universe at all.
But it doesn't eliminate the need to explain why there should be a
physical universe - rather it speculates that the UD will
necessarily produce not only thread of consciouness but also a
physics for consciousness to relate to. But that's why I thing the
"reversal" is a cheat. The physics is necessary to the
consciousness - whatever is "primary".
Mathematics is ontologically necessary: God is not needed to create
the number 2 and can't get rid of the number 2 even if he is
omnipotent. Primary physical existence lacks this quality of
ontological necessity.
That's like saying conjunction is ontologically necessary: God is
not needed to create "and".
Lol.
We don't need an "and" for having the truth of "the sky is blue and
there is a bird". You need only the "and" to communicate that truth to
someone else. Similarly the number two exists, even in a world without
a "t","w","o". And the fact that 4 added to 3 gives 7 is independent
of all syntactical conventions we might decide to use to communicate
that fact about our reality.
We cannot prove the existence of the numbers, nor can we prove our
consciousness, but in both case, I tend to think that we all believe
in them. people claiming they don't believe in them might talk about
something else, or add metaphysical baggage which is not there. The
amount of realism is the acceptation that in principle any digital
machine on any argument will stop or will not stop. Arithmetical
realism is redundant, because it is part of Church's thesis. (I say
this for Bruce).
Arithmetic is non logically redundant, though. You can't derive the
arithmetical axioms from logic alone, and that is why I assume them,
and put the card on the tables, as it is better to do when digging on
very deep and complex problem.
Bruno
Bruno
Brent
--
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 [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
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 [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
