HERE are people whose brain activity was completely stopped, and who were later revived (or impeached)—
A few were accidentally submerged in icy water long enough to reduce their body temperatures sufficiently to halt all functions up to and including brain activity, while others were deliberately cooled for the purpose of performing otherwise difficult or impossible surgery.
Unless there is presently in place some cryptonatural or incorporeal means of maintaining or transferring consciousness, based on the results of our previous investigations these people may no longer possess the same consciousnesses they had prior to these events.
The self-awarenesses they had before their brains stopped would have fallen victim to the same thing that would have happened had their brains permanently died— without some unknown mechanism for preservation and transfer, the same people post-brain-stoppage now unknowingly possess new consciousnesses.
With memories and personalities identical to their corresponding pre-brain-stoppage awarenesses, these post-consciousnesses are unable to recognize that the recollections they inherited, or were "born" into via bodies and brain cells, are not their own pasts. Neither can their family or friends discern any difference.
There may be people breathing, walking, and making love right now who literally aren’t their old selves, with no one the wiser— including themselves!
Consequently, persons considering the undertaking of surgery that involves stoppage of all brain activity should know that whether or not their corporeal entity survives the operation, the result for them may be the same, the cessation of earthly awareness and involvement.
If the patient gets out of bed however, family and friends will not suffer— the new consciousness will be a perfect counterfeit, and the lack of transfer will be impossible to detect.
There will be cases, particularly with the accident instances, where the brain activity stoppage is approached but then escaped. As in Thought Experiment #3 in the previous chapter, to avoid a binary/analogue disjunction we should consider the possibility of a partial loss of consciousness, that does however retain the likelihood of being fully-regainable.
It has been observed that trying to preserve a person cryogenically (by freezing solid) is too slow a process to keep from destroying enough of his memory to make resuscitation impossible, no matter how advanced our reconstructive abilities ever become.
Yet even should instantaneous freezing and thawing techniques be perfected that safeguard recollection, the procedure won’t work unless some level of brain activity can be maintained outside of or independent of the body.
It can be perhaps be slowed or even partially stopped, but if shut down entirely the person that wakes, while claiming to be the original individual, will— like the cooled people— actually have a new awareness.
Likewise, science fiction writers have hypothesized about the possibility of being able to teleport travelers by dematerializing them at point of origin and reassembling them at their destination, such as in the Star Trek series.
Even if ever physically possible this may never be safe, for the simple reason that the extent to which conscious activity can be disrupted may never be certain.
The teleported person would feel sure he was the original person, but there would be no way to validate his belief, nor would the original person be around to ask what happened to him.
(On the positive side, if such a manipulation of animate matter was within the realm of possibility, transporting inanimate matter would be a cinch, eliminating once and for all the problem of lost luggage.)
Finally, when we do build a machine with a true awareness of it’s own existence and mortality, we may have to pass a law stating that it is illegal to turn it off or unplug it, since that will be morally equivalent to murder.
True, it could be turned back on and reprogrammed with the same memory, but then, although identical, it would be a new individual, not the old one resurrected.