Introduction 
13 
may also have contributed to this tendency to reify “the em- 
bryo” in its early stages (though such reification has likely al- 
ways played a role in embryology.) The ex vivo existence of 
nascent human life is genuinely puzzling and may invite ter- 
minology that can be distorting.* 
If the term “the embryo" risks conveying the false notion 
that embryos are distinct kinds of beings or things, the term 
“spare embryo” risks making a difficult moral question seem 
easier than it is. The term is frequently used to describe those 
embryos, produced (each with reproductive intent, but in ex- 
cess of what is needed) in assisted-reproduction clinics, that 
are not transferred to a woman in attempts to initiate a preg- 
nancy. No longer needed to produce a child, they are usually 
frozen and stored for possible later use, should the first efforts 
fail. But the “spareness” of a “spare embryo” is not a property 
of a particular embryo itself; it bespeaks rather our attitude 
toward it, now that it may no longer be needed to serve the 
purpose for which it was initially brought into being. Calling 
something “spare,” or only “extra,” invites the thought that 
nothing much is lost should it disappear, because one already 
has more than enough: one has “embryos to spare.” It also ab- 
stracts from the distinct genetic individuality of each embryo 
and invites the view that embryos are, like commercial prod- 
ucts, simply interchangeable — an outlook that may affect the 
further judgment of any embryo's moral standing. To be sure, 
most of these unused embryos will die or be destroyed. To be 
sure, if these unused embryos are otherwise destined for de- 
struction, a case can be made — and debated — ^that their un- 
avoidable loss should be redeemed by putting them to use be- 
forehand. But the moral question regarding their possible use 
and destruction should not be decided — here, as elsewhere — 
* The Council is well aware of the fact that the debate about abortion shad- 
ows all these discussions about "embryos." Yet in all of our work to date, on 
cloning and stem cell research, we have called attention to the fact that we 
face a rather different moral situation when we are dealing with embryos in 
the laboratory, in the absence of concerns for a pregnant woman’s life and 
future. Accordingly, we explore the ethical issues of embryo research by ad- 
dressing what we know (and how we know) about ex vivo human embryos, 
separate from any issues that enter when the interests of pregnant women 
are engaged. 
PRE -PUBLICATION VERSION 
