This is a wonderful (and classic) question, sometimes referred to as the 'inverted spectrum' thought experiment -- but it turns out that the philosophy of color (and color perception) are far more complicated than one might intuitively think, given our everyday familiarity with and intuitions about colors ... The short, easy answer to your question is of course yes: it certainly seems conceivable that different individuals label different color perceptions with the same name (no need to insist on the stronger thesis, as you actually phrase it, that each individual's color perception is different from every other's, is there?). Moreover I believe that, on a simple level, the 'yes' answer has been empirically demonstrated, more or less: different people will identify rather different wavelengths as 'yellow' say (which is strictly neutral on what's going on inside them, but at least suggestive of the 'yes' answer). But one can get very sophisticated here and perhaps build one's way to a 'no' answer, so the...

great question -- though it's not like there is 'an' answer here, though there is much to be debated as you formulate your own anwer. For one thing one must try to separate 'the 'experience from the language we use to speak about it and focuse on the experience. And anecdotal (incl medical) evidence seems to suggest it's no uncommon for people to report things, under anesthetics of various sorts, that they are having terrible pains but somehow don't mind them. That prima facie suggests that that very experience, the painful one, doesn't have to be a cause of pain, so to speak -- which suggests it is NOT inherent in pain to be avoided/disliked. (Lnguage complicates this b/c we might choose to use the word pain in that restrictive manner and thus claim those un-minded experiences do not earn the label 'pain' -- that's a semantic choice but it doesnt seem to effect the ontological conclusion.) hope that is helpful ...

Wow, fantastic email -- getting at the heart of some major philosophical ideas and movements. Empiricists tend to stress the role of perception/experience in producing knowledge, while rationalists tend to promoe the role of reason, often arguing on the basis of such considerations as those you mention. A couple of quick thoughts about the specifics of your message. Your example of a problematic perception (spinning cube looks like sphere) doesn't quite/fully show that perception is problematic, partly because some other perception is relevant to getting at the truth, ie seeing the cube not spinning. The rationalist might say that reason is needed to process these otherwise conflicting perceptions, but even if this so, it does seem that perception is playing a key role in generating our knowledge of the world (that a cube exists, and that, when spun, it looks spherical) -- so what you've raised is a kind of problem for perception, but not one which obviously (to me anyway) undermines the importance...

Great question -- and in fact you have your finger on a version of what is ultimately perhaps the strongest argument for a mind-body dualism -- ie the view that mind and body/matter are completely distinct sorts of things. One way to put it is this way: with eyes closed I am seeing (say) a shining sun; but it isn't the real physical shining sun I am seeing (b/c my eyes are closed); therefore I am seeing some non-physical thing, a mental thing, a mental image or representation OF the physical shining sun. Therefore there exist mental things which are distinct from all physical things .... So the phenomenon you invoke is at least strongly suggestive that there are two kinds of seeing, or two kinds fo things seen: mental and physical .... Now, having said that, there are various ways phlosophers have resisted these kinds of arguments -- you might want to look up a philosohper named JJC Smart, and his work on the "identity theory" (denying dualism) to see how he resists these arguments .... Also one...