Rex Allen wrote:
> On Sat, Jul 18, 2009 at 11:55 AM, Bruno Marchal<marc...@ulb.ac.be> wrote:
>> I am OK with all this. It has to be like this if we take the comp hyp
> So what are your thoughts on my question as to whether abstract
> concepts other than numbers also exist in a platonic sense? For
> example, the idea of "red"?
> So obviously we can cast everything as numbers and say, "In this
> program, 0xff000000 represents red". But RED is what we're really
> talking about here, and 0xff000000 is just a place holder...a symbol
> for what actually exists.
> In your view, Bruno (or David, or anyone else who has an opinion),
> what kinds of things actually "exist"? What does it mean to say that
> something "exists"?
Well, since you asked, I think "exist" is always relative to some
domain; so we should use "exist" in different senses. First of all I
think epistemology precedes ontology. We first get knowledge of some
facts and then we create an ontology as part of a theory to explain
these facts. Facts are obtained in different ways. Chairs and tables
and people exist at the most basic level of epistemology, i.e. we
directly perceive them. Sometimes it is argued that we don't really see
tables and chairs, we see 2-D patches of color and infer tables and
chairs. This is the error of the misplaced concrete. Perhaps as
infants we saw patches of color, but as adults our brain processes
information differently and we directly perceive 3D objects. That we
have theories of vision that tells us we're "really" experience certain
excitations of the visual cortex or that tables and chairs are "really"
quarks and electrons with lots of empty space are beside the point.
Those are ontologies built on other theories that were inferred from
perception of macroscopic 3D objects.
Something similar happens with mathematical objects. We learn language
intuitively and built into language are certain logical and mathematical
structures so that we come to perceive conjunction and disjunction and
the natural numbers and some other concepts directly. Do these
mathematical objects "really" exist? I'd say they have
logico-mathematical existence, not the same existence as tables and
chairs, or quarks and electrons. Similarly we may, in another domain,
say that Sherlock Holmes violin exists but Sherlock Holmes tuba does
not, based on the reading of Conan Doyle.
> It seems to me that maybe consciousness is actually very simple. It
> is just a group of platonic ideals, like red, that are related to each
> other by a point of view: "I like red", or "I see a red sphere."
> Maybe what is complicated is constructing or identifying a causal
> structure (e.g., a machine, a brain, a program, etc) whose evolving
> state can be interpreted as representing a series of "connected" or
> "related" instances of consciousness. But the machine (physical or
> otherwise) is NOT that consciousness, the machine just represents that
> In this view, consciousness itself consists directly of the abstract
> platonic ideals that form the contents of a given moment of
>> It remains to explain the relative stability of that illusion. How and
>> why some dreams glue, in a way sufficiently precise for making
>> predictions about them.
> Maybe unstable illusions exist, but, being unstable, don't ponder such
> Obviously we have such conscious beings here in this world, with
> schizophrenics and the like.
> So your questions about "why are my perceptions so orderly", would NOT
> be universally valid questions, because there are conscious entities
> whose perceptions are NOT orderly.
> And I would say that even my perceptions are not consistently orderly,
> as when I dream I often experience strange scenarios.
> To say that dreaming and hallucinating are special cases I think is to
> make an unfounded assumption. It would seem to me that orderly
> perceptions are the special case, and dream-logic realities would be
> the norm.
> If consciousness is in some way a result of computation, then a
> program that generates all possible mind-simulations will surely
> result in the vast majority of resulting minds experiencing
> dream-logic realities, not "law-and-order" realities like ours.
> I think Sean Carroll (who I'm reasonably sure would disagree with
> everything I've proposed above, but still) had a pretty good point on
> such "counter-intuitive" predictions:
> "The same logic applies, for example, to the highly contentious case
> of the multiverse. The multiverse isn’t, by itself, a theory; it’s a
> prediction of a certain class of theories. If the idea were simply
> “Hey, we don’t know what happens outside our observable universe, so
> maybe all sorts of crazy things happen,” it would be laughably
> uninteresting. By scientific standards, it would fall woefully short.
> But the point is that various theoretical attempts to explain
> phenomena that we directly observe right in front of us — like
> gravity, and quantum field theory — lead us to predict that our
> universe should be one of many, and subsequently suggest that we take
> that situation seriously when we talk about the “naturalness” of
> various features of our local environment. The point, at the moment,
> is not whether there really is or is not a multiverse; it’s that the
> way we think about it and reach conclusions about its plausibility is
> through exactly the same kind of scientific reasoning we’ve been using
> for a long time now. Science doesn’t pass judgment on phenomena; it
> passes judgment on theories."
> So, I could continue further and go into a lengthy defense of why I
> think this supports what I'm saying, BUT maybe you'll come to the same
> conclusion I have and I can save myself a lot of typing! So, I'll
> just try that approach first.
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