The privacy of consciousness

See the note to the following post for the origins of this material.

We can in fact "measure" consciousness, at least in principle, as indicated in operations that directly stimulate the brain of waking patients, who report resulting conscious experience, or qualia (to actually measure a conscious experience, we would need to run those operations in reverse, in a sense: instead of noting experiences as we apply electrical current, we would note current changes as patients were presented with experiences). But of course this is just needles on dials, ink on graph paper, or whatever, not consciousness itself. We're pretty sure, in such a situation, that we are measuring consciousness because we believe that other people, including this patient, are conscious, and the patient is telling us his or her experience. But still, all we have is just the report and the recording instruments – we can't seem to observe consciousness itself. It seems intuitively obvious that consciousness is, in a very fundamental sense, private ... but why, exactly?

Well, again, let's suppose that consciousness were a mechanism that consisted of two major components, fitted to one another -- call them World and Actor, or W and A. And then consider two different conscious mechanisms, C1 and C2:

C1 = W1-A1
C2 = W2-A2

Any observation of any form – measurement, direct perception, whatever – reaches the awareness of the observer only through W. But that awareness itself is only present in the connection between W and A. So if C1 wanted to observe the consciousness of C2, say, even if C1 were to take apart or dissect C2, all that C1 would be able to observe would be what came to it via W1 – through that portal, so to speak, it could observe C2 as a whole, or observe the separate parts W2 and A2, but it could not *observe* C2's consciouness because that's a phenomenon that only occurs at the Actor (or maybe Awareness) level, i.e., at the A1 or A2 level. For C1 really to become aware of C2's consciousness, it would need to get its A1 component in direct connection with C2's World component – that is, it would have to dissect not just C2 but also itself, and then re-wire its own A1 to C2's world:

C1-2 = W2-A1

Which would make an interesting basis for a science-fiction plot (though no doubt Philip K. Dick has already done something like that), but is otherwise unlikely.