"How do you know other humans can truly experience "yellowness"? What if we're all just pretending and you're the only one?" To me, that's kind of a silly ques

"How do you know other humans can truly experience "yellowness"? What if we're all just pretending and you're the only one?" To me, that's kind of a silly question. Yes, it might be true. Of course, it might be that there are no other human beings and I'm just a brain in a vat. I just find that hypothesis to be too unlikely to care about. "We're just putting together lego blocks and at the end is a human indistinguishable from any other human. Does this person experience qualia?" I would guess so. "How would you know?" For me, this is a little like your first question. I wouldn't necessarily know. But if this entity is physically indistinguishable from a human at even the most infinitesimal level of physical reality, I'd assume it experiences. But, I may be wrong here, because it might be that there is something non-physical called a "soul" that resides in humans, and a physically identical entity might not be provided with one by God or whoever/whatever the soul-provider is. That's not what I tend to assume, but I have no evidence either way. Your question "How would you know" is an interesting one because it assumes that it matters whether or not an observer knows. Maybe some entities have awareness and others don't, and an observer can't tell the difference. So what? That wouldn't imply, in any way, that the phenomenon of awareness doesn't exist. "Once you take apart the argument like this, it's easy to see that arguments that computers can't experience qualia are arguments against materialism or reductionism, or are patent attempts to sneak souls and other woo into the discussion." That doesn't mean that such arguments/hypotheses aren't true. It just means they may not be testable using the scientific method. Much as many people don't like the multiverse theory because it may not be testable using the scientific method. But that merely means that there are limits to the truths that can be discovered by the scientific method; it doesn't change the reality of what is true. It's a bit reminiscent of Godel's completeness theorem. Many great mathematicians assumed that there were no truths that weren't provable within the systems they were studying; Godel proved that such assumptions were simply wrong.