Re: When does an (M,R) system cease to be alive?

["Tim Gwinn" <***>]

Hi Jeff et al,

So, then, is metabolism all that is necessary in order to say that an
organism is alive? In an ameoba (for example) that has no heart, is the
cessation of metabolism when life deemed to have ceased? It seems right.

What, then, is this apparent distinction between "being alive" and "life"?

Well, I just went back to section 1B ("Why the Problem is Hard") in "Life
Itself". There he states that the question "what is life?" is really a "why"
question in disguise, and "that we are really asking, in physical terms, why
a specific material system is an organism, and not something else."

Using this statement suggests rewording as follows:
"Why life?":
- We are really asking, in physical terms, why a specific material system is
an organism, and not something else.
"Why alive?":
- We are really asking, in physical terms, why a specific material system is
alive, and not dead.

So, then, the questions are notably distinct, and as a result, it now seems
to make sense that the answers will be different. It also seems obvious that
the first question ("why life?") must include, as part of its answer, an
answer to the second question ("why alive?") as well.

But doesn't that also imply that the question "why life?" is about more than
just being alive? What does that "more" consist of? It must be something
other than just being closed to efficient causation, since Rosen apparently
backed off of  "closed to efficient causation" as a sufficient condition.
So, what else must it include?

This intrigues me since we now have a different kind question than usual.
Rather than "why an organism instead of not an organism?", we now are asking
"Why is being an organism different than, and more than, being alive?"

To me, what initially jumps to mind is 'persistence': the idea that an
organism includes the notion of an innate ability to persist.This goes
beyond an ability to be alive for a few more seconds or hours. But what is
it that persists? Persistence implies stability: in order to identify a
system as being the 'same' system over time means that some thing(s)
identifiable about that system remain stable. Is it the functional
organization that is what is stable and persists? Or, is persistence not
even a crucial aspect?

Regards,
Tim


> -----Original Message-----
> From: ROSEN Forum [mailto:*** Behalf Of Jeff
> Pridaux
> Sent: Tuesday, October 07, 2003 5:39 PM
> To: ***
> Subject: Re: When does an (M,R) system cease to be alive?
>
>
> These is a very interesting thread...
>
>
> One may make the "provocative" simplifying assertions that "metabolism" is
> what proteins do...
>
> Repair is the manufacture of more proteins by RNA
>
> Replication is the manufacture of more RNA... (by special proteins)
>
> If one were to suddenly get a disease that prevented replication in the
> above sense, then the person would no longer be "closed to
> efficient cause"
> but would by most people's definition still be alive until the persons
> metabolism stopped.  Assume metabolism is sufficiently stopped when the
> heart stops...
>
> I agree that "life" and "being alive" are two different notions.