(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!
No, but I can use it to make a point about how low your bar for meaningfulness is. Does that not count for some reason? I asked you before to propose a meaningless statement of your own. Do none exist? Are none of them grammatically correct?
???
Yes, the unicorns don't have to be undetectable be definition. They're just undetectable by all methods that I'm aware of. If "invisible unicorns" have too much undetectability in the title, we can call them "ghost unicorns". But, of course, if you do detect some unicorns, I'll say that they aren't the unicorns I'm talking about and that you're just redefining this profound problem to suit you. Obviously this isn't a perfect analogue for your "robot pain", but I think it's alright.
So, what you're saying, is that you don't know if "ghost unicorns" exist? Why would Occam's razor not apply here? How would you evaluate the likelihood that they exist?
And what I said before is that a well-formed sentence can robustly be said to be meaningful if it embeds a contradiction, like "colourless green", or category error, like "sleeping idea".
Very low finite rather than infinitessimal or zero.
I don't see how this is helping. You have a chain o... (read more)