I guess this would be my attempt to answer your first question: articulating what I meant without the phrase “level of death”.
My answer to your second question it tougher. Somewhat compelling evidence that whatever I value has been preserved would be simultaneously experiencing life from the point of view of two different instances. This could be accomplished perhaps through frequent or continuous synchronization of the memories and thoughts of the two brains. Another convincing experience (though less so) would be gradual replacement of individual biological components that would have otherwise died, with time for the replacement parts to be assimilated into the existing system of original and earlier-replaced components.
If I abruptly woke up in a new body with all my old memories, I would be nearly certain that the old me has experienced death if they are not around, or if they are still around (without any link to each others’ thoughts), that I am the only one who has tangibly benefited from whatever the rejuvenating/stabilizing effects of the replication/uploading might be, and they have not. If I awoke from cryostasis in my old body (or head, as the case may be) even then I would only ever be 50% sure that the individual entering cryostasis is not experiencing waking up (unless there was independent evidence of weak activity in my brain during cryostasis).
The way for me to be convinced, not that continuity has been preserved but rather that my desire for continuity is impossible, does double duty with my answer to the first question:
whatever routine occurrence it is that supposedly disrupts my brain state as much as a destructive scan and rounding to the precision limit of whatever substrate my copy would be running on.
I guess this would be my attempt to answer your first question: articulating what I meant without the phrase “level of death”.
My answer to your second question it tougher. Somewhat compelling evidence that whatever I value has been preserved would be simultaneously experiencing life from the point of view of two different instances. This could be accomplished perhaps through frequent or continuous synchronization of the memories and thoughts of the two brains. Another convincing experience (though less so) would be gradual replacement of individual biological components that would have otherwise died, with time for the replacement parts to be assimilated into the existing system of original and earlier-replaced components.
If I abruptly woke up in a new body with all my old memories, I would be nearly certain that the old me has experienced death if they are not around, or if they are still around (without any link to each others’ thoughts), that I am the only one who has tangibly benefited from whatever the rejuvenating/stabilizing effects of the replication/uploading might be, and they have not. If I awoke from cryostasis in my old body (or head, as the case may be) even then I would only ever be 50% sure that the individual entering cryostasis is not experiencing waking up (unless there was independent evidence of weak activity in my brain during cryostasis).
The way for me to be convinced, not that continuity has been preserved but rather that my desire for continuity is impossible, does double duty with my answer to the first question:
[Unambiguous, de-mystifying neurological characterization of...]