Whoever would have predicted even three months ago that stem-cell research would occupy the presidential mind and roil congressional heavy thinkers? But here it is, much like abortion (about which more later).
What can one say about it? A lot.
Stem cells are blastocysts, or cell clusters, that may be programmable to develop into various specific cells and tissues - and so to repair the afflicted. Science has a lot still to learn about the full extent of stem cells' beneficial use.
Researchers harvest stem cells from several sources - principally (1) from frozen petri-dish embryos no longer needed because the donors are on their way to parenthood; (2) from petri-dish embryos grown only for the cultivation of stem cells, and then destroyed; (3) from aborted fetuses; and apparently (4) from umbilical cords and other forms of adult tissue.
The debate goes generally to No. 2 above. A Virginia company is in precisely that business - essentially the same company that two decades ago gave the planet the first in-vitro, or test-tube, baby. A Massachusetts company, in the words of one news account, "is trying to use cloning technology to create human embryos that would yield [stem] cells, which in turn might give rise to tissues that were a perfect match for patients," thereby diminishing to near zero the rejection of implanted tissue.
Bioethicists are having a field day.
Says the University of Wisconsin's Alta Charo, "These two techniques involve embryos that would not have been lost. So they put, quite squarely, the question of how we balance our interest in protecting people who are already born and our interests in protecting embryonic life." The University of Chicago's Leon Kass notes adults may provide stem cells equally as promising as stem cells provided by embryos.
Both men suggest a central question in the developing stem-cell debate: What is the best, most prudent source of stem cells? (Indeed, a National Institutes of Health Report requested by President Bush, advises: "During the next several years, it will be important to compare embryonic stem cells and adult stem cells in terms of their ability to proliferate, differentiate, survive, and function after transplant, and avoid immune rejection.") Related questions arise the moment the mind begins to wander....
Is it ethically OK to draw stem cells from embryos created solely for research, as opposed to stem cells from leftover embryos or aborted fetuses? Are petri-dish embryos, created for whatever reason, human life? Conversely, is the destruction of petri-dish embryos the destruction of realized, inchoate, or potential human life? Is human cloning OK? (Ian Wilmot, the Scottish cloner of Dolly the sheep, offers an emphatic no.)
Should federal money fund research on stem cells drawn from petri-dish embryos? Does the 5-year-old congressional ban on federal funding of embryo research already apply to research on embryo cells? What about the 1993 law imposing ethical restrictions on fetal tissue research?
And, most crucially, when does life begin?
Which brings us to abortion.
Absolutists on one side say it begins at conception. The same people tend to say all research on embryos is wrong because petri-dish embryos constitute human life. Absolutists on the other side say life begins at birth. The same people tend to say all embryo and fetal research are fine because life does not begin until successful birth - as one would expect from individuals who support even partial-birth abortion, the killing of a fetus before it totally exits the birth canal.
Science could hugely help us answer lofty questions about abortion and stem-cell research if it would come to some agreement as to when life begins. At conception? At heartbeat? At brain wave? At quickening? At birth? The answer, whatever it is, would make issues like abortion and stem-cell research a piece of cake.
Until science provides that definitive answer - which it may never do - science and the nation, even the larger global community, must proceed cautiously.
Some clichés come to mind. One is federal money means federal control. That is largely true, and it means that in funding stem-cell research the federal government can greatly restrict it, for whatever good that will do. Yet who, including government, can stop science - or control it or restrict it?
Another is the truth, wherever it may lead. But the pursuit of scientific truth has led here and elsewhere to the atomic bomb and biochemical weapons. What if The Truth ultimately is that life begins at conception: Do we then continue with tossing petri-dish embryos into the trash? And of course, the Soviets' Pavlov and the Nazis' Mengele, and their epigoni, have done some of the most grisly things, and on government subsidy, the world has ever seen.
For good or ill, science will roll on. Whether it rolls in the proper (in this case, proper bioethical) direction will depend on our own ethical prescriptions and our own humaneness - and most prominently on the humaneness of the scientific community itself.