(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!
Here is my claim that "robot feels pain" is a meaningless statement. More generally, a question is meaningless, if an answer to it transfers no information about the real world. I can answer "is purple bitter" either way, and that would tell you nothing about the color purple. Likewise, I could answer "does this robot feel pain" and that would tell you nothing about the robot or what you should do with it. At best, a "yes" would mean that the robot can detect pressure or damage, and then say "ouch" or run away. But that's clearly not the kind of pain we're talking about.
Since you are equaiting reality with objectivity, you are simply declaring statements about subjectivity meaningless by fiat.
That's because it is a category error.
Of course it tells me what I... (read more)