what is alive?

Kevin W L Croft kcroft at server.blo.su.oz.au
Sun Sep 22 17:39:22 EST 1996


Steve McGrew wrote:
>         Wouldn't it make sense to consider "living" to be a matter of degree?
> For example, a dried lotus seed or a frozen spore *must* be considered to be
> alive to some degree, since it has the capacity for doing all the things
> living things do.  A person in a coma is less alive than one who is engaged in
> a lively conversation.  A virus is perhaps less alive than a eukaryotic
> organism, which in turn may be less alive than a dog.  And, a cancer cell is
> certainly alive, but perhaps to a lesser degree than the organism whose stem
> cells it arose from.
>         Certainly we could cook up a definition for "life" that would provide
> a basis for calculating the "degree of aliveness" of a system, so that each
> animal, plant, virus, autonomous robot and river system can be allocated its
> own aliveness.

Your post seems to conflate "being alive" with "being active".  I'm
ready to accept that we can distinguish between levels of activity among
different creatures, and even for the same creature at different times. 
However, this doesn't mean that there is more or less life in the
comparisons.

I maintain, as I have argued elsewhere, that life is an all-or-none
phenomenon.

If you can, as you say, "cook up a definition for "life" that would
provide
a basis for calculating the "degree of aliveness" of a system" without
merely characterising different levels of activity, I would be very
interested in seeing it.

Regards,

Kevin Croft

Kevin W L Croft
Graduate Student
Unit for the History and Philosophy of Science
The University of Sydney
Australia

kcroft at server.blo.su.oz.au



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