"You could conceivably lose half your brain and live. Which means your brain could conceivably be split into two halves and each transplanted into different bodies."
Unfortunately this does not follow. In most cases, if you lose half your brain you would die. If by chance, after losing half your brain you continue to live, that means the physical half that is gone was the less essential part. I am not a neurologist but I'd guess it is very unlikely that if you lost the part that survived you could still live.
Actually, people have had entire hemispheres of their brain removed and continued to survive, with other parts of the brain taking over for the jobs of the removed parts.
In addition, to treat epilepsy brain surgeons sometimes cut the corpus callosum, or the nerves connecting the two hemispheres. The two halves of the body act almost like the bodies of two different people who just happen to be connected.
Unfortunately this does not follow. In most cases, if you lose half your brain you would die. If by chance, after losing half your brain you continue to live, that means the physical half that is gone was the less essential part. I am not a neurologist but I'd guess it is very unlikely that if you lost the part that survived you could still live.
Regards,
Atakan Gurkan