Monitoring Stem Cell Research 
75 
human embryology. Nearly all participants in the dispute make 
some reference to biological findings, whether to claim that 
they teach us about an embryo’s essential continuity with and 
similarity to human beings at other stages of life, or to argue 
that they reveal profound and morally meaningful discontinui- 
ties between embryos and live-bom persons. 
While we examine these differing contentions, it is cmcial 
to remember — as several commentators in recent years have 
noted — ^that the biological findings, however relevant, are not 
themselves necessarily decisive morally.^^ 'They may serve bet- 
ter to challenge moral positions founded on erroneous assump- 
tions than to ground some positive moral affirmation or conclu- 
sion. For example, a recognition of biological continuity might 
in some measure undermine the argument that embryo de- 
stmction is permissible when certain biological markers or 
states of development are absent. But it would not by itself 
show indisputably that embryos are to be treated as simply 
inviolable. Meanwhile, recognizing the biological significance 
of some particular point, marker, characteristic, or capacity 
would not, in itself, imply some decisive moral significance. A 
description of early embryonic development is necessary 
though not sufficient to an understanding of the nature and 
worth of an early embryo.’^® It is not sufficient because any 
purely biological description requires some interpretation of its 
anthropological and moral significance before it can function 
as a guide to action."^® 
With these provisions in mind, we offer the following brief 
review of developments in the debate over the moral standing 
of human embryos in the past several years.* 
A. Continuity and Discontinuity 
Many participants in the debate take the question of the 
biological continuity or discontinuity between nascent and 
later human life to be crucially significant. Some argue that the 
fundamental organismal continuity from the moment of fertili- 
zation imtil natural death means that no lines can be drawn 
between embryos and adults. Others argue, on the contrary. 
* Readers may find it helpful to consult the notes on Early Human Develop- 
ment (Appendix A). 
PRE -PUBLICATION VERSION 
