"Eliezer S. Yudkowsky" wrote:
> Mark Gubrud wrote:
> >
> > I agree it is in principle possible, within known physics, to copy the
> > pattern of function and interconnection of the brain, and to implement a
> > functional equivalent in some type of computer. Such a process could be
> > termed "copying the contents of a brain."
>
> I don't know if you're aware of this, but the atoms within the brain do
> not remain constant. I forget what the exact rate of turnover is, but
> something like 50% of the atoms get replaced every six months. So
> whatever "we" are, it's clearly not the atoms.
>
> If you scan in one neuron at a time, destroy the old neuron, and replace
> it with a robotic interface to equivalent computations taking place
> elsewhere, you can migrate, one neuron at a time, to the new substrate,
> without ever losing consciousness. In this case, would it not be
> possible to say that the new individual is unambiguously "you", with the
> change of physical substrate as irrelevant as the turnover among your
> constituent amino acids?
>
This reminds me of an old problem called "Theseus' Ship." Here is a bit about
it from _Labyrinths of Reason_ by William Poundstone:
> When Theseus returned to Athens after slaying the Minotaur, his ship "was perserved by the Athenians down even to the time of
> Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their place," wrote
> Plutarch. "This ship became a standing example among philosophers, for the logical question as to things that grow; one side
> holding that the ship remained the same, and the other contending that it was not the same."
>
> Everyone concurs that replacing a plank on a ship does not change its identity. It is still the same ship after the replacement.
> Replacing still another plank on the repaired ship should not make a difference either. At some point, perhaps, Theseus' ship
> contained not a single plank of the original ship. Then surely the Athenians were deluding themselves in calling it Theseus' ship.
> Had the ship not been perserved, and had the latter-day Athenians constructed a ship directly from those same nonoriginal planks,
> on one would dream of calling it anything but a good replica of Theseus' ship.
>
Which leads me to ask, what do you upload, when you upload?
-Ken
This archive was generated by hypermail 2b29 : Thu Jul 27 2000 - 14:06:46 MDT