> Side question: how do we know if humans possess qualia? I think there are some people who don't possess qualia, or maybe don't notice that they have it. Ther

> Side question: how do we know if humans possess qualia? I think there are some people who don't possess qualia, or maybe don't notice that they have it. There was a reddit post years ago from a guy who said he only became self-aware in adulthood, like a light switched on in his brain one day. And it wasn't "becoming self-aware" in a metaphorical sense (like learning responsibilities or how you are perceived by otheres), it was described as the real-deal: consciousness of subjective experience. One day he didn't have it, the next day he did. There are also various accounts of people losing subjective consciousness while nevertheless awake and able to walk and clothe and feed themselves -- neurological conditions, "ego death". Another reason I believe this comes from reading accounts of aphantasia. Such people can go their whole lives not realizing that most people can see images in their minds eye. A consistent theme is their assumption that phrases like "imagine", "see in your minds eye", "picture this: ...", "flashed through my mind", "cannot unsee", etc were just metaphors, like how when we say "take the bull by the horns" we're not talking about a literal bull or literal horns. To them it was a shock that people really had pictures in their minds, because they had never experienced such a thing. (Reiterating for anyone reading this who is confused: yes most people can literally see imaginary things, overlaid on top of the normal visual field. If you find this surprising, you have aphantasia). So if this supposedly universal subjective experience can be absent in some people, and they don't realize it because they think the language is metaphorical, then perhaps that could happen for everything else. Or maybe not everything else, but some kind of spectrum, where some people only have very weak, barely noticeable qualia, and others get it much stronger. In fact, if we suppose a naturalistic origin of consciousness, I think it has to be the case that it's a spectrum. Nature rarely produces sharp binaries. I think I have experienced this myself during certain kinds of dreams, where the self seems fractional, ghostly. Maybe some people live like that all the time. How would we know? Then at the other end of the spectrum, there might be people with intense subjective everyday experience. There are accounts of drug trips where everything just felt more, in some indescribable way -- what if some people don't need drugs for that? And likewise, for any qualia-lackers or consciousness-lackers who are reading this: yes, qualia is a real thing. It's not a metaphor or a language-game. It does actually feel like something to exist.