These people believe this while at the same time considering dualism so ridiculous as to laugh dualists out of the room. The evident problem being that "mind uploading" is the most dualistic possible position to take. A real monist would easily see that by doing mind uploading you have just created a clone that is a whole separate entity from yourself and it is not yourself.
Oft-repeated but not true. Neurons, for the most part, are never replaced. If a neuron dies, it's gone forever. Repeated head traumas (leading to CTE) are known to cause personality changes as the brain has been permanently altered due to neuron losses.
Invoking the Ship of Theseus is a distraction. The Ship of Theseus paradox does not involve a full copy at the atomic level while the original still stands. If it did, the paradox would not even exists. The paradox exists because there is the key element that you do not have in mind copying/uploading: _continuity_.
Edit: Just to clarify my opinion: This means that the relationship between my self from five seconds ago and my current self and the relationship between my self from five seconds ago and a clone of that self that aged the same amount would be equivalent. Both of us would _not_ be the same as my past self
The easiest rebuttal would be to simply say that continuity is not a mere implementation detail. If you give up continuity, you can make a copy without altering the original, you just have to read it.
But if you need to ensure continuity you have to alter the original. This seems to me a very fundamental part of the process, making it qualitatively different.
If not, what if the aliens recycled the atoms from your original body to make the new body, putting each original atom into the same original spot with the same position and momentum (ignoring quantum and uncertainty principle).
What if they recycled 99% of the atoms from your original body, but swapped 1% of them for different atoms?
What if they only destroyed 5% of your brain and reassembled that destroyed portion, leaving the rest of you untouched? What about 50%?
What if they waited 1 planck moment before reassembling you versus 5 seconds?
Where is your dividing line in this scenario space between "that's really me" versus "that's just a copy and is not really me" ?
The functionalist answer, as I understand it, is fungibility across time and copies when arriving at definitions of words like "you".
The functionalist answer is not that > 1 copy can communicate telepathically or supernaturally share experiences is a dualist sense. They are still causally independent physical entities.
The functionalist answer, as you understand it, is dualist. It says "something" survived the utter complete destruction of the physical body and was "put back in it" once it was reassembled. If "it" survived the complete physical destruction of the body, it must be somewhere else, detached from the body.
And, you know, there's really nothing wrong being dualist. I do not mean to denigrate that specific worldview. What is problematic is claiming to be a staunch monist while holding dualist positions.
I think that many who talk about consciousness digitization handwave away what happens to their body/brain afterwards, but I don't necessarily think that means they think they'll move into the computer.
That's reducing an individual to, I assume, the sum of its neural network. So like considering everything else happening in the fleshy body matters to what a human is, nor how they relate to the rest of cosmos as such a body.
