In philosophy, qualia (/ˈkwɑːliə/ or /ˈkweɪliə/; singular form: quale) are individual instances of subjective, conscious experience. The term "qualia" derives from the Latin neuter plural form (qualia) of the Latin adjective quālis (Latin pronunciation: [ˈkwaːlis]) meaning "of what sort" or "of what kind"). Examples of qualia include the pain of a headache, the taste of wine, or the perceived redness of an evening sky.
Daniel Dennett (b. 1942), American philosopher and cognitive scientist, regards qualia as "an unfamiliar term for something that could not be more familiar to each of us: the ways things seem to us".
Erwin Schrödinger (1887–1961), the famous physicist, had this counter-materialist take:
The sensation of color cannot be accounted for by the physicist's objective picture of light-waves. Could the physiologist account for it, if he had fuller knowledge than he has of the processes in the retina and the nervous processes set up by them in the optical nerve bundles and in the brain? I do not think so.
I notice that Wolfgang has again waded into the qualia debate, in the form of an attack on the conception of narrative as a key to the definition of self.
If it is obvious to me that the reality of qualia cannot be doubted and you think there is nothing even there to discuss, it is another strong hint that our conscious experience is actually quite different. Perhaps we experience colors with different intensity (but what exactly would that mean?).
I don't think it can be doubted that each of us has a different conscious experience, at least if we specify that our conscious experience includes our memories and our sensory experiences. My problem is trying to figure out what a phrase like "the reality of qualia" means, if anything. The essential quality of "qualia" is that they are purely individual but my test of "reality" depends heavily on it being shared.
In any case, I wonder if the curious case of the woman who has orgasms in her left foot has anything to say about qualia?
In her case, it seems that an infection may have caused some cross talk among the neurons from her foot and from her vaginal area. Similar cross talk effects appear to afflict those who "hear" colors or, tragically, feel touch as pain.
On the one hand, such pathological cases suggest that different sensations for similarly named experiences are quite real. On the other hand, the identification of their physiological basis suggests that Schrödinger was mostly wrong.