I like the story. To me the issue is not about the denial of sensation but rather about its status. We seem to understand sensation (the 'what it's like to see red') as radically private. At the same time we thoughtlessly assume that of course we all have access to the 'same' redness. The unspoken logic seems to be that the same-enough hardware should provide the same-enough radically-private-experience-stuff. But whence this 'should'? Anything that's radically private by definition is seemingly outside the purview of logic and science, by definition.

Yeah, but is the same substance "physical"? It could be neutral monism or mental, or panpsychism could be the case. Chalmers has argued that consciousness is an additional property tied to informationally rich processes.

The issue is whether a physical account of the world is complete. The world is whatever it is, which includes conscious sensations. How do we best understand the world?

To me the issue is not about the denial of sensation but rather about its status. We seem to understand sensation (the 'what it's like to see red') as radically private. At the same time we thoughtlessly assume that of course we all have access to the 'same' redness. — hanaH

I'm not sure that we do. Seems that sensation varies a bit. Some people report seeing different shades of color than I do. But I'm not an artist. I do notice that some people are better at discriminating tastes or sounds than others. Still, it does seem similar enough under normal circumstances. You can go read an Oliver Sacks book for odd neural experiences.

he unspoken logic seems to be that the same-enough hardware should provide the same-enough radically-private-experience-stuff. But whence this 'should'? Anything that's radically private by definition is seemingly outside the purview of logic and science, by definition. — hanaH

It's an assumption since other humans are biologically similar and speak a shared language. May it's not quite so radically private since humans share common biology, behaviors and languages. But for other creaturs like bats, it does seem to be radically private. The best we can do is suggest that bat sonar sensation is either like sound or color for us. But we really don't know. It could be something else entirely for bats. After-all, they do already have ears and eyes. Same with dolphins and whales.

I would argue that sensation is somewhat radically private, in that we never fully know what it's like to be someone else. Only what their behavior and words tell us, and to the extent that our projection or simulation of their minds is accurate. Which often enough, it's not.

I would argue that sensation is somewhat radically private, in that we never fully know what it's like to be someone else. Only what their behavior and words tell us, and to the extent that our projection or simulation of their minds is accurate. Which often enough, it's not. — Marchesk

For me there's a delicate issue here: how can words and behavior indicate sensation in the strict sense? Imagine a supervised learning scenario. I never have access to the sensations of others. I have no data in which I can discover correlations. The concept of private sensation (as solipsistic philosophers need it be) leads to a kind of hidden dimension that we shouldn't be able to reason about (indeed, we can't even say it's one dimension.)) The reason we can and do is (arguably) because 'redness' is primarily a pattern in our social behavior. Basically the hidden dimension serves no purpose.

Nevertheless I believe that I see the redness of red. I just don't know exactly what that's supposed to mean. (Nor do I know exactly what 'physical' is supposed to mean.)

Maybe Alien Sonar Mary would know what it is like to be a bat.

And how would you classify that information?

My guess is that language isn't just tied to external behavior, but also things like mirror neurons in that we project our own experiences onto others, as long as they're similar enough to us. We infer similar subjectivity in others. This does break down in various situations. If there was no radical privacy, one would think it would never break down.

If you consider gravity physical - which Newton did not, incidentally - but we do, I don't see why we can't say that the same "substance" which causes gravity also causes experience. If not, then we'd have to have different substances for each phenomena in nature. I don't see what is gained by doing this.

Yes, it could be neutral monism, it could be mental and it could be panpsychic. I don't quibble much with neutral monism, it's fine.

I'm a huge fan of the mental, but I don't see any reasons for believing phenomena which provide no evidence of mental processes should be thought to be inherently mental. Same for panpsychism.

This is not to say that the view which states that the world is a construction of our minds on the occasion of sense data, is false. On the contrary, I believe it to be true. But I don't think anything mental underlies nature.

There are sensations unknowable to science. We only know the human ones because we have them. Otherwise, humans would be like bats, to an alien or AI science lacking those sensations. — Marchesk

I'm not sure what you mean by "unknowable to science." Unknown, sure. We know about some senses that other organisms have that we do not. As I noted, there are animals who can sense magnetic and electrical fields.

.