Mental Qualia (qualities)
Qualia...definition: “from a Latin word meaning for ‘what sort’ or ‘what kind,’ is a term used in philosophy to refer to subjective conscious experiences as 'raw feels'.”
“There are many definitions of qualia, which have changed over time. One of the simpler, broader definitions is "The 'what it is like' character of mental states. The way it feels to have mental states such as pain, seeing red, smelling a rose, etc.”
On Light and Color:
"Remember how infinitesimally small our visible light spectrum is compared to what’s really out there? Just try to imagine a brand new color — it’s impossible. Or imagine trying to explain to someone who’s been blind their whole life what red looks like. You could say that it makes you feel warm and you associate it with passion, but what would they really understand or imagine red to be? They could know everything there is about light and color and it would still be as a foreign concept to them. There just aren’t words that allow someone to grasp the true meaning of something they haven’t experienced for themselves, which is known as an explanatory gap." Source:10 Illuminating Facts About Light and Color
Qualia are instantiations or mental events of conscious sensory experiences. In other philosophical terms, qualia are properties of sensory experiences by virtue of which there is something it is like to have them.
In “Materialism and Qualia: The Explanatory Gap” published in Pacific Philosophical Quarterly in 1983. "Levine addressed the puzzling inability of physiological theories to account for psychological phenomena. Levine’s main focus was on consciousness, or “qualia,” our subjective sensations of the world. But the explanatory gap could also refer to mental functions such as perception, memory, reasoning, and emotion—and to human behavior.”
Qualitative Character as Mental Representation
Qualitative features of mental states are often called "qualia" (singular, "quale"). In recent philosophy of mind that term has been used in a number of confusingly different ways, but here I shall use it in a specific, fairly strict sense that comes to us from C.I. Lewis (1929) by way of Goodman (1951)(though there is plenty of room for exegetical disagreement about Lewis' own usage). A quale in this sense is a qualitative or phenomenal property inhering in a sensory state: the color of an after-image, or that of a more ordinary patch in one's visual field; the pitch or volume or timbre of a subjectively heard sound; the smell of an odor; a particular taste; the perceived texture of an object encountered by touch. (The term "inhering in" in the preceding sentence is deliberately vague, and neutral on as many metaphysical issues as possible. In particular, qualia may be properties of the experiences in which they inhere, or they may be related to those experiences in some other way.) For reasons that will become clear, we may call this sense of "qualia" the "first-order" sense. Notice that it differs from the broader and vaguer sense defined in the entry on qualia ("the introspectively accessible, phenomenal aspects of our mental lives"), and from the much more heavily laden sense of Block (1990, 1995, 1996), according to which "qualia" are by stipulative definition neither functional nor intentional properties. Source: Lycan, William, "Representational Theories of Consciousness", The Stanford Encyclopedia of Philosophy (Spring 2005 Edition), Edward N. Zalta (ed.), Qualia and the Explanatory Gap
"Our grasp of what it is like to undergo phenomenal states is supplied to us by introspection. We also have an admittedly incomplete grasp of what goes on objectively in the brain and the body. But there is, it seems, a vast chasm between the two. It is very hard to see how this chasm in our understanding could ever be bridged. For no matter how deeply we probe into the physical structure of neurons and the chemical transactions which occur when they fire, no matter how much objective information we come to acquire, we still seem to be left with something that we cannot explain, namely, why and how such-and-such objective, physical changes, whatever they might be, generate so-and-so subjective feeling, or any subjective feeling at all.
This is the famous "explanatory gap" for qualia (Levine 1983, 2000). Some say that the explanatory gap is unbridgeable and that the proper conclusion to draw from it is that there is a corresponding gap in the world. Experiences and feelings have irreducibly subjective, non-physical qualities (Jackson 1993, Chalmers 1996). Others take essentially the same position on the gap while insisting that this does not detract from a purely physicalist view of experiences and feelings. What it shows rather is that some physical qualities or states are irreducibly subjective entities (Searle 1992). Others hold that the explanatory gap may one day be bridged but we currently lack the concepts to bring the subjective and objective perspectives together. On this view, it may turn out that qualia are physical, but we currently have no clear conception as to how they could be (Nagel 1974). Still others adamantly insist that the explanatory gap is, in principle, bridgeable but not by us or by any creatures like us. Experiences and feelings are as much a part of the physical, natural world as life, digestion, DNA, or lightning. It is just that with the concepts we have and the concepts we are capable of forming, we are cognitively closed to a full, bridging explanation by the very structure of our minds (McGinn 1991)." Source: Tye, Michael, "Qualia", The Stanford Encyclopedia of Philosophy (Summer 2003 Edition), Edward N. Zalta (ed.),