I've been following this thread with great interest and was contemplating it over lunch. It occurred to me that regarding the notion of potentiality and personhood, perhaps a different distinction would be more helpful. The point of contention seems to be that anything that has the potential to be a person should be protected from destruction, but as demonstrated by this thread, this notion can become controversial when you try to define both the term "potential" (does a cell,  or a sperm, etc. constitute potential?), and the term "person" (is it cognizance, a heart beat, etc.?). It seems to me that some of this debate could be alleviated if you introduced a third "category" if you will, or intermediary step - the term "human".
you shouldn't have had to deal with that.
delineated or circumscribed as some seem to suggest.
Christians, I'm mostly focused on issues of integrity.
should take a somewhat different tack on this subject.
those things that we want to protect at almost any cost.
am proposing it as a better way to think about personhood.
5.  I see nearly all arguments for "personhood"
my symposium talk at the ASA meeting in 2006.
I don't suggest that my position is beyond cavail.
get it; frankly, it's lame.
something a whole lot better than "manipulation"
by the body. Ah, but that leads us to the fertilized ovum.
adequacy of the conception definition of personhood .
others) cause me to lean in the direction voiced by Burgy.
researchers are not insensitive to the ethical concerns. Dr.
flawed way such that they cannot develop into a viable baby.
embryonic stem cell research (and vice versa!).
analysis is not by any means obvious.
-- a position with which I'm quite sympathetic.
"does a frozen embryo have personhood -- a soul?"