OK, but it’s not too hard to describe what makes a thing blue. The only obvious sticking point is who’s standard of blueness we’re using. Perhaps a “blueness function” would be better than an equivalence class of all things blue, then. Regardless, determining whether or not a given thing is blue doesn’t seem to be what the OP is asking about; I’m suggesting that this suffices.
I think you’re missing the point of the post. The problem is about blue qualia, not the category blue. There would still be blue in a world of p-zombies, but not blue qualia.
Well we wouldn’t want to “just define” a word that’s supposed to refer to something in the world, without figuring out what that thing is yet.
OK, but it’s not too hard to describe what makes a thing blue. The only obvious sticking point is who’s standard of blueness we’re using. Perhaps a “blueness function” would be better than an equivalence class of all things blue, then. Regardless, determining whether or not a given thing is blue doesn’t seem to be what the OP is asking about; I’m suggesting that this suffices.
I think you’re missing the point of the post. The problem is about blue qualia, not the category blue. There would still be blue in a world of p-zombies, but not blue qualia.