You may feel that pain is special, and that if we recognize a robot which says "ouch" when pushed, to feel pain, that would be in some sense bad. But it wouldn't. We already recognize that different agents can have equally valid experiences of pain, that aren't equally important to us (e.g. torturing rats vs humans. or foreigners vs family).
I don't see how it follows from the fact that foreigners and animals feel pain that it is reasonable to recognize that a robot that is programmed to say "ouch" when pushed feels pain. Can you clarify that inference?
suggesting that some agents have a magical invisible property that makes their experiences important, is not a good solution
I don't see anything magical about consciousness - it is something that is presumably nearly universally held by people, and no one on this thread has suggested a supernatural explanation for it. Just because we don't as-of-yet have an objective metric for consciousness in others does not make it magical.
it is reasonable to recognize that a robot that is programmed to say "ouch" when pushed feels pain
No, I'm saying that "feels pain" is not a meaningful category. Two people could disagree about whether this robot feels pain, but then agree completely about how the robot should be treated. My example or rats was meant to point out that "feels pain" is very different from "deserves human rights".
no one on this thread has suggested a supernatural explanation for it
No one has suggested any explanation for it at all. And I do use "magical" in a loose sense.
(This post grew out of an old conversation with Wei Dai.)
Imagine a person sitting in a room, communicating with the outside world through a terminal. Further imagine that the person knows some secret fact (e.g. that the Moon landings were a hoax), but is absolutely committed to never revealing their knowledge of it in any way.
Can you, by observing the input-output behavior of the system, distinguish it from a person who doesn't know the secret, or knows some other secret instead?
Clearly the only reasonable answer is "no, not in general".
Now imagine a person in the same situation, claiming to possess some mental skill that's hard for you to verify (e.g. visualizing four-dimensional objects in their mind's eye). Can you, by observing the input-output behavior, distinguish it from someone who is lying about having the skill, but has a good grasp of four-dimensional math otherwise?
Again, clearly, the only reasonable answer is "not in general".
Now imagine a sealed box that behaves exactly like a human, dutifully saying things like "I'm conscious", "I experience red" and so on. Moreover, you know from trustworthy sources that the box was built by scanning a human brain, and then optimizing the resulting program to use less CPU and memory (preserving the same input-output behavior). Would you be willing to trust that the box is in fact conscious, and has the same internal experiences as the human brain it was created from?
A philosopher believing in computationalism would emphatically say yes. But considering the examples above, I would say I'm not sure! Not at all!