Re: [asa] scientific fact vs. ideology?

From: David Campbell <>
Date: Wed Mar 18 2009 - 15:19:22 EDT

> The "certain level of ...mental function" that I (& others) have suggested
> is anything above zero.  I.e., I would be happy to say that once the brain,
> or any neural structure, begins to form, the embryo should be considered a
> person.  It seems to me that with this criterion there is no question about
> the personhood of those with Alzheimers, the comatose, &c.  Part of the
> rationale for this is the parallel with the criterion of brain death at the
> end of life - which means whole brain death, not coma, vegetative state, &c.

That is certainly a coherent and reasonably precise criterion
(determining exact line between zero and some is likely to be
difficult, and "any neural structure begins to form" would need to be
defined as to whether it includes the point at which a cell is
definitely destined to form neurons versus the point at which a cell
first shows any sign of neuronal features). However, "life begins
with neural activity" seems no less arbitrary than "life begins at

Some things that might be of interest philosophically, though not
directly applicable to human development, come from consideration of
other animals. Sponges do not have any neurons at any point, though
they have some capabilities for slow motion, internal communication,
etc. They easily reproduce asexually by fragmentation, so the concept
of an "individual" is somewhat blurry.

Looking at more advanced animals, the vast majority have cell fates
set from the start of embryonic development. There are no twins
formed the way human twins are (some can asexually multiply embryos,
though). From the very first cell division, the exact part of the
embryo that will become neurons is fixed. Thus, the scenario would be
somewhat different if arthropods or mollusks were considering the same

Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"
To unsubscribe, send a message to with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Wed Mar 18 15:20:04 2009

This archive was generated by hypermail 2.1.8 : Wed Mar 18 2009 - 15:20:04 EDT