I'd tend to say that "quality" is typically a term used for question-begging. People define "quality" to mean something which cannot be purely physical, although they tend to hide it behind a layer or three of foofle.
"Quality" = something = something else = something that cannot be physical.
I don't think we have "qualia" so much as "sense data". You can't hive off "redness" from degree of redness, size of redness, brightness of redness and so on with the stroke of a pen, and that's what I think the qualia brigade tend to do.
I think you have identified the nub of the materialist vs phenomenalist debate. I assert that any particular quality doesn't need these various
relational parameters you mention, whereas you disagree. Are you right in saying we can't just hive off size, brightness and degree from redness? I don't think so. I think you are mistaken for
attaching these relational definitions and attempting to define redness as such in the first place. They simply have no bearing on the qualitative nature of redness to begin with.
You might say, "colour is determined by a particular wavelength of light emitted from the object and this refers to the degree and brightness of redness". But here, we are dealing with mathematical relationships in our definition of brightness and degree. In other words, we can give a full account of a particular wavelength, polarisation and amplitude of light and have no reason to refer to anything else. "..of redness" doesn't come into it. I think this inevitably leads us into the knowledge argument with Mary in the black and white room etc, an argument I find quite valid.
Probably, but it might turn out you could define it at a physical level as well. It might turn out that the experience of seeing redness happens to be a particular brain state which is objectively observable, and that I could induce the state of seeing redness by zapping a particular bit of a person's brain with an electrode, even if they had never seen red.
The same argument applies here with regards to physical descriptions being mathematical whereas redness is not. I think you are trying to explain this by saying that the description of brain processes is from the "outside" whereas the actual brain processes themselves are on the "inside" and equal the experience of redness, and hence this is why we can never fully describe the "inside" experience because that would mean actually being on the inside and thus losing the objectively observable brain processes on the outside. Bit of a long-winded sentence but is that what you're roughly saying? If so you are confronted with the following problem:
a) we have a description of objectively observable brain processes and the actual brain processes themselves the latter of which equals redness.
b) we have a description of objectively observable brain processes and the actual brain processes themselves, the latter of which
does not equal redness.
I'll assume you regard a) and b) as being simultaneously possible. It is clearly the addition of the term redness that distinguishes these two scenario's since a) includes redness in the statement whereas b) does not. How would you define redness here?
Also, you refer to someone "seeing redness" after zapping their brain. What do you mean by redness here?
I suspect you mean the same thing I do - the qualitative nature of an experience.
