Once again, the US Senate will be debating embryonic stem cell research. It will consider two bills this week: one which is nearly the same as a bill vetoed by President Bush last year which will expand and encourage this research. The other is a compromise measure which will foster research on "dead" human embryos or on cells extracted from living embryos without destroying them. It also will support the creation of a stem cell bank for cells extracted from amniotic fluid and placentas.

The looming debate was the occasion for some thoughtful commentary from both sides of the debate. Harvard professor Michael Sandel, a supporter of destructive embryo research, points out in the Boston Globe that President Bush's position is inconsistent. If he really does believe that embryos are human persons, surely he ought to seek to ban it completely, not merely deny it federal funding.

And in National Review an opponent, Yuval Levin, of the Ethics and Public Policy Center, zeroes in on an inconsistency in the first bill, which was passed last year by the House of Representatives. However, its supporters have now added provisions for funding alternatives such as reprogramming adult cells and deriving stem cells from amniotic fluid. These methods have shown great promise in recent months, probably more than embryonic stem cells. So what is the point of federal funding research for destructive methods "just at the moment when ethical alternatives may be emerging", he asks.