[Avodah] what is death- what is life?

[hankman]

RMB wrote [on an Areivim thread, in which R' Dr Noam Stadlan, and
R Moshe Shmuel Svarc are debating]:
> RDNS and RMSS differ one step ahead of what they're discussing explicitly:
> Do chazal mean that any body that doesn't breathe have a soul in it and
> those that can do? Perhaps we should note that the words for soul are
> all ones for breath: uach, nefesh and neshamah/neshimah all. Or do chazal
> mean to give us a diagnostic tool -- any body so far gone as to not have
> breath doesn't have a soul in it, but those that do have breath may or
> may not have the unstated criterion necessary to be able to house a soul?

> RMSS assumes chazal are saying that whether or not a person is breathing
> is the very physical change that causes the soul to leave.

> RDNS assumes that chazal are giving a diagnostic tool, and do not specify
> what the physical change is. And so, to quote, he is still left asking:
>: what exact quality makes you a human being, and, more specifically, makes
>: you the unique human being that you are?

> And this issue is implicitly raised by RnTK's point, that in the case of
> pesiq reishei, we don't need to check. Now the question is, why not? I
> can think of a variety of answers:

> 1- Headlessness is a second valid diagnostic tool for knowing that the
> body lost that unnamed quality needed to hold a soul.

> 2- Because we can assume that a headless body isn't breathing, so there
> isn't even piquach nefesh justification for violating Shabbos to check
> for breathing.

> 3- Because when Chazal speak of breathing, they don't bother telling
> you it needs to be breathing instigated by the brain stem since the
> technology for artificial breathing wouldn't exist for another 1,500
> years. But that was really what was meant -- a body in which the moach
> isn't telling the reichayim to breathe can't house a soul. And so we have
> a gemara pointing to breathing, and another talking about a lack of moach.

CM raises a hypothetical:

What if we have a case of psik reisha that is breathing and whose heart
is beating -- would all agree that this person is indeed dead?

So for our hypothetical, we have a skilled medical team standing by at
the guillotine for the execution of a prisoner, who immediately and
before any serious loss of blood is allowed to happen attach the now
open vascular system and trachea at the neck to a heart-lung machine
specially designed for this purpose and treat the open wound to prevent
infection. The now headless person is on "life support" and the body from
the neck down survives the ravages of "death" and decay and continues
its metabolic processes -- I assume this is possible and not too far
beyond our current technology, though I am not really sure (can anyone
with a medical degree venture an opinion if just basic tissue metabolism
can actually continue under these conditions -- simple tissue and cells
clearly can do this in a petri dish so why not our hypothetical?). I
imagine we would also have to feed him intravenously etc.

Would anyone still consider this person (body?) alive, or would all
agree he is dead? Did Chazal mean even this case too?

Kol tuv
Chaim Manaster