Introduction 
5 
senting only a few genetic backgrounds, have been made. 
Thus there is continuing scientific interest in developing new 
embryonic stem cell lines, and the existence of large numbers 
of stored cryopreserved embryos in assisted-reproduction clin- 
ics provides a potential source for such additional derivations. 
Complicating the debate has been the study of another group 
of stem cells, commonly called "adult stem cells,” derived not 
from embryos but from the many different tissues in the bodies 
of adults or children — sources exempt from the moral debate 
about obtaining ES and EG cells. For this reason, we often 
hear arguments about the relative scientific merits and thera- 
peutic potential of embryonic and adult stem cells, argiiments 
in which the moral positions of the competing advocates might 
sometimes influence their assessments of the scientific facts. 
Further complicating the situation are the large commercial 
interests already invested in stem cell research and the com- 
petition this creates in research and development not only in 
the United States but throughout the world. The seemingly 
small decision about the funding of stem cell research may 
have very large implications. 
n. BROADER ETHICAL ISSUES 
While most of the public controversy has focused on the is- 
sue of embryo use and destruction, other ethical and policy 
issues have also attracted attention.* Although entangled with 
the issue of embryos, the question of the significance and use 
of federal funds is itself a contested issue: Should moral con- 
siderations be used to decide what sort of research may or 
may not be funded? What is the symbolic and moral-political 
significance of providing national approval, in the form of ac- 
tive support, for practices that many Americans regard as ab- 
horrent or objectionable? Conversely, what is the symbolic and 
moral-political significance of refusing to support potentially 
life-saving scientific investigations that many Americans re- 
gard as morally obligatory? 
« 
Introduced here, these issues and the discussions they have produced will 
be reviewed in Chapter 3. 
PRE -PUBLICATION VERSION 
