Qualia

Qualia ( /ˈkwɑːliə/ or /ˈkweɪliə/; singular form: quale is a term used in philosophy to refer to individual instances of subjective, conscious experience. The term derives from a Latin word meaning for "what sort" or "what kind." Examples of qualia are 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, writes that qualia is "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 colour 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."

The importance of qualia in philosophy of mind comes largely from the fact that it is seen as posing a fundamental problem for materialist explanations of the mind-body problem. Much of the debate over their importance hinges on the definition of the term that is used, as various philosophers emphasize or deny the existence of certain features of qualia. As such, the nature and existence of qualia are controversial.