In particular Bryan says
Alas, as in past arguments, he doesn’t answer my fundamental complaint: There’s nothing in the physics textbook, or any other hard science source Robin can name, that even tries to bridge the gap between a bunch of neurons firing and the indubitable facts that I feel pain, think that Tolstoy was a great novelist, or love my children.
. . .
In short, "We’ve looked at your physical parts, failed to find pain, therefore pain is physical." This just begs the question. Robin just can’t take seriously the logical truism that you can’t see pain through a microscope. Unless you personally experience it, it’s inference, not observation – hence the "problem of other minds."
From a philosophical standpoint I take the problem of other minds seriously. From a practical standpoint I don’t. The fact that other’s express pain is enough for me to believe that they do and to structure my life as if they do. The fact that the structures of the brain seem to be the at least the source of if not the essence of consciousness are enough to make me care deeply about my loved one’s brains. The analog between neural interactions and behavior are strong enough to make me believe its those interaction that count.
Knowing his penchant for wagers I would offer Bryan the following thought bet. A family member is unconscious and suffering from a disease that will kill him or her in the next X amount of time. If a brain emulation is performed now, the original body will die immediately, but the Em will live on indefinitely. If we wait any amount of time the then emulation can no longer be performed.
What is the
smallest largest X for which you would be willing to try the Em?