The Sword and Laser discussion

The way stem cell work is going they will soon be able to replace or repair every type of human organ Replacing most parts really doesn't matter since the only thing that really make you-you is your brain. As cell in your body die they are replaced by new cells.
Your brain was supposed to be the exception.

Conventional medical wisdom held that your brain cells lasted a life time.
(neurons in the cerebral Cortex, for example are not replaced when they die).
So ~ there will never be another you~

Then about 10 years ago they were working on Parkinsons disease
and found that the adult brain does have the potential to repair itself.
(Science magazine 12007). At which point replacing human brain cells it went from
"Impossible;" to "Maybe.” This whole sector is moving a lot faster then expected.
It does raises an interesting question. Even when the new cells are grown from your original ones.
At what point do you become a new you?

I believe the process is continual. Our identity is constantly changing. Who we are today is but the "closest continuer" to who we were.

Casey wrote: "I believe the process is continual. Our identity is constantly changing. Who we are today is but the "closest continuer" to who we were."

One neat thing about scifi geeks is that we make up words for all kinds of interesting ideas. Before discussing this book, I hadn't heard the term "closest continuer", but it's an interesting thought.

I have mental continuity, so I am still me. Now whether that me is the same me that I am now is the question, though I might argue that it is an irrelevant question.

That's interesting. It brought up the thought of a tree which makes seeds then spreads them out to grow into new "clones" of itself. Physically our cells might renew, but our consciousness stays the same, so, maybe not "new", but refurbished?

Joanna wrote: "One neat thing about scifi geeks is that we make up words for all kinds of interesting ideas. Before discussing this book, I hadn't heard the term "closest continuer", but it's an interesting thought."

Yeah. There are some really smart folks around here. But the "closest continuer theory" belongs to Robert Nozick. I can follow him for the most part, but if I haven't got my coffee, he torques my brain a bit.

Diego wrote: "That's interesting. It brought up the thought of a tree which makes seeds then spreads them out to grow into new "clones" of itself. Physically our cells might renew, but our consciousness stays th..."

But our consciousness doesn't stay the same. People are changing constantly; we're inconsistent and contradictory. What we call "personality" is nothing more than a pattern of behavior, and the behaviors that don't fit the pattern get dismissed as "mood" or the vagaries of psychology. When we look at our own "personality," we either explain away the inconsistencies by concocting justifications for our actions, or simply ignoring them, sometimes even altering our memories to fit what we want to believe.

Oooh, the Brain of Theseus. Great idea for a novel, at least.

Rob wrote: "Oooh, the Brain of Theseus. Great idea for a novel, at least."

Greg Egan covered the subject quite thoroughly in Permutation City.

That looks interesting, and I'll check it out, but from the goodreads summary it looks more like it addresses the Altered Carbon question about copypasta people, not whether or not you're still the same person if over ______ years your brain was slowly but surely regenerated in your skull.

The book deals with digitized minds, but the Ship of Theseus issue is still present as people deal with the implications that the hardware they're running on is being upgraded with new components, or in some cases that they're being run on a distributed network with parts of their brain being swapped between server farms around the world.

I've also wondered about this. I read an article (Omni magazine?) where it postulated replacing neurons with an artificial version that functioned the same. If you replaced 100 cells were you still you? You can lose that many after too many beers. Then if you kept doing this over time eventually you replace the entire brain. Also normal neurons are chemo-electrical, imagine if the artificial neurons were purely electrical and worked at that speed. Or if each worked like a WiFi connection and spread out. Are you still you?

Todd wrote: "I've also wondered about this. I read an article (Omni magazine?) where it postulated replacing neurons with an artificial version that functioned the same. If you replaced 100 cells were you still..."
Thanks. Sounds like an interesting article. If you find it please pass along the link.
OBTW- The entire Omni collection is on-line at the internet archives.
https://archive.org/details/omni-maga...

Sean wrote: "But our consciousness doesn't stay the same. People are changing constantly; we're inconsistent and contradictory. What we call "personality" is nothing more than a pattern of behavior, and the behaviors that don't fit the pattern get dismissed as "mood" or the vagaries of psychology. "

You're right consciousness doesn't stay the same. I think I generalized to much in my previous explanation lol. By our consciousness staying the same, I meant more along the lines that, our fundamental awareness, our "being" stays. It might evolve with new information and ideas, but it doesn't become new 100%, just different (I guess this goes along the reincarnation idea. Soul/consciousness goes from existence to existence, but there is only one of it ect.) And I'm not sure personality is consciousness. Personality, to me, seems like a conglomerate of egos, habits and insecurity -- window dressing that can get replaced with each new passing season. Well, that's my 2-cents anyway. :)

We are assuming here that the brain creates the mind/consciousness/personality which is us. But some argue that the mind is a completely separate thing/something Other than the body. See the mind-body problem rampant in philosophy.

I at least don't, to take my original argument that continuity is all, if you were to transfer my consciousness into another body, I would remain the same person. However if the backup that was used was say 3 weeks old, then I would no longer be the person who died, but I would be the person who was backed up. Even though the person who died and the person who was backed up were the same person.
Another interesting thought is that of an amnesiac, I would make the argument that after the memory loss they are a different person from before. However if the memory's returned then the pre-memory loss person and the post memory loss person would stop being distinct individuals and become one. The all important continuity of consciousness having been restored.
Just my humble take on things.

We are continually changing what we know and what we have experienced. So in one sense we might say we are not the same person we were - but in another sense we are not a different person in that our future person is still cognizant of all the experiences of the old person.

But that's a different question to what the OP asked originally. Brain cells are pretty much just on off switches. Replacing them even with artificial switches shouldn't make a difference. Brain cells don't have any internal intelligence or "brain" of their own deciding what to do. Else they'd be thinking before there was any thinking going on - I think.