Jackson's Mary
At a recent talk at BU about Consciousness, Steven Horst, a professor of philosophy at Wesleyan advanced an apparently well-known argument by Frank Jackson. The argument uses the thought experiment of a woman named Mary, kept in a controlled environment of black, white and grey, and at the same time made to know everything that the most advanced future (omni)science of the physical world can possibly tell her about the brain. Now, argues Jackson, when she is made to see something red at last, she learns something new that could not be contained in such knowledge. And thus, concludes Horst with Jackson, there is something beyond the physical world that is necessary for this experience to happen.
Of course this vulgar mystical argument is based on a typical confusion between object and representation — the ultimate source of insanity according to Korzybski.
If Mary does have only a theoretical knowledge of her own brain,
any information she has is about a model of her brain,
a representation disconnected from knowledge of herself;
making her see something red is then a new experience indeed,
by which Mary may relate her representation (of her brain) to the object.
On the other hand, if Mary's scientific source of knowledge
really allows her to know everything
about the physical state of her own brain,
then amongst that "everything" is the ability to inspect
the effect of observing the effect of actually firing her own red neurons.
In other words, the interactive knowledge of her own physical state
indeed includes her being able to simulate and register
the effect of seeing red
by manipulating her own brain
(through e.g. electrodes, nanobots or other implants).
The absurdity of the situation is entirely due to Frank and Horst
using a fallacious semantic shift between knowledge of the object
and knowledge of a disconnected representation
in the everything
that Mary knows or doesn't know.
No argument for or against physicality is actually present in this fallacy.
In fact, when we get to the bottom of the argument, we find not an indictment of the scientific experimental method, but a glorious vindication of it. Indeed, experiencing is something essential that goes beyond abstract knowledge: it is only by experimenting with physical phenomena that we can tie any non-tautological theoretical proposition to reality. Theoretical knowledge is not knowledge before it is somehow made to map actual physical interactions with the world. Certainly, theory, deductive logic, praxeology, induction, are necessary tools to allow for any kind of understanding of facts that would otherwise be but meaningless sound and fury. But only interaction with reality may allow to distinguish which amongst consistent theories are to prevail and which are to be rejected.
In the end, Horst is correct of course in his further claim that physicalism isn't an experimental scientific statement: it is an epistemological statement. But it isn't a matter of faith or revelation like mystics would have it, it is a provable epistemological truth. If we can know a phenomenon through interactions with the physical world, then it's physical indeed, and not supernatural. And if we can't, then any claim that it exists and that we know of it are preposterous. It is precisely the experimental method that may allow us to tie representation to the world: can you or can you not interact with the phenomenon and thus experimentally establish any reproducibly predictable regularity about it? If yes, then it is anything but supernatural, it is the valid subject of scientific knowledge. Show us the reproducible experiment, and we'll include this regularity amongst the known physical laws of nature. If you can't, then how can you speak of a phenomenon to begin with?
The utterly unspeakable is utterly irrelevant.
And whatever speakable claim there is
that mystics make
of phenomena that would exist beyond knowable nature
and may override or contradict the laws of nature,
is actually the claim that random assertions by them
must be accepted despite the lack of supporting evidence
and the availability of contradicting evidence.
These are but lazy and dishonest claims
by which some pseudo intellectuals
draped in pompous academic or religious titles
try to smuggle unjustified and unjustifiable claims
without having to pass any elementary test of validity.
Rejecting such claims is not even a question of reason and science.
It's a matter of basic intellectual honesty.

Platonic ideas vs reality
Realists consider knowledge as the interactive feature of a physical mind,
operating on a representation that is related to the known object only through indirect potential interaction.
Platonists are indeed insane, by Korzybski's criterion. They can't distinguish the notion of representation.
However, I don't agree with your definition of 'mysticism' as dealing with 'the utterly unspeakable'. In my experience, it's quite the opposite - it's dealing with very real, literal data which can be observed. Actual practicing mystics, the kind of people who do 'remote viewing' or have precognitive dreams, are fairly hard-core scientists, in the sense that they make a habit of experiencing and documenting interesting mental states.
Obviously such self-mental-observation falls into the category of 'experience' but there's nothing particularly philosophically special about the act of experience *itself*. So it's not a matter of 'Mary is seeing data which is not IN PRINCIPLE available to science' but rather that 'Mary is seeing a data stream which merely isn't recognised by the mainstream of science TODAY, but does exist'.
The broad claims of such 'mysticism' - ie in the body of documents produced by such people - are that there is stuff happening in the internal mental state which does not necessarily correspond to the sum total of information available to the body through the 'usual' senses. If true - and there's a substantial body of support for these type of anomalous mental phenomena - then it follows that yes, there is an external objective reality - but that this reality is mental in nature, in that it's *directly accessible by the internal mental faculties*.
I'm talking of course about the current state of the art in psi and ESP studies. A number of interesting books have been released lately which describe the body of objective evidence for anomalous mental states *with physical results*. In particular I recommend these:
* Entangled Minds by Dean Radin
* Extraordinary Knowing by Elizabeth Meyer
* Irreducible Mind by Kelly et al (the motherlode of documentation: http://www.amazon.com/Irreducible-M
I find the autoganzfeld experiments particularly compelling, but I've had a number of anomalous cognitive experiences myself. The more I read in teh literature, the more I discover that they're much more common than one might expect.
Regards
I don't think anyone denies that meditation, introspection, asceticism, mental and physical discipline, can have a lot of practical, observable, effects. What is being dismissed, for good reasons, are the explanations of those effects as supernatural phenomena involving forces that transfer energy or information outside the body of the meditating person. What is being laughed at, for just as good reasons, are claims that these experiences reveal anything about the universe, great cosmic principles even, when they only reveal delusions of the human mind.
Your ESP explanations will be much more credible once one of your gurus claims and wins one of the many million-dollar prizes offered to whoever can provide evidence of such phenomena.
As for a representation -- the representation is not the thing. The idea of red is not red. The idea of an invisible pink unicorn is not an invisible pink unicorn. The idea of a flawless diamond in my pocket is not a flawless diamond in my pocket. And my use of the word "pocket" does not imply that such a pocket actually exists. "Knowing" "everything" about a representation is indeed not the same as experiencing the thing. And doctors may know about disease and death without experiencing either (yet) - which may help avert them (for a time). The fuss that Jackson makes is ultimately based on insanity, the inability to distinguish between a thing and its representation (or the willful fallacy of slipping from one to the other).
Perhaps, but those are secondary.
"What is being dismissed, for good reasons, are the explanations of those effects as supernatural phenomena involving forces that transfer energy or information outside the body of the meditating person. What is being laughed at, for just as good reasons, are claims that these experiences reveal anything about the universe, great cosmic principles even, when they only reveal delusions of the human mind."
On this I'm afraid we must disagree. I believe that the already accumulated scientific data as described by Radin, Puthoff et al *do* describe exactly such a transfer of information.
"Your ESP explanations will be much more credible once one of your gurus claims and wins one of the many million-dollar prizes offered to whoever can provide evidence of such phenomena."
Why? James Randi is not a scientist - and it's already been well documented that he does not present a level playing field. In any case, winning such a prize would have no scientific value. Those who have rigorously scientifically investigated ESP phenomena - such as J B Rhine, who coined the word - have already accumulated 150 years worth of solid data.
I believe ESP is a case where those who wish to see, see; those who do not wish to see, choose to exclude the evidence from their set of data. It's actually a reverse of the 'file drawer problem'.
"As for a representation -- the representation is not the thing. The idea of red is not red. The idea of an invisible pink unicorn is not an invisible pink unicorn."
With this I agree wholeheartedly, having spent a fair bit of time poking at knowledge representation and database theory (hence my interest in TUNES).
Best regards.