Paul Greenberg

Within weeks of this groundbreaking discovery, scientists at the Whitehead Institute in Cambridge, Mass., announced that they'd used these new, reprogrammed cells to cure sickle-cell anemia - in mice, anyway.

But such developments aren't likely to have much effect on those determined to experiment on human embryos. Scientific achievement, fame and fortune, the chance to make good by doing good, or just the urge to satisfy human curiosity, will continue to spur the race to the top of this particularly greasy pole.

Those who oppose cloning human embryos in order to destroy them for purposes of scientific research will still be called anti-science, or be accused of being callous to the plight of patients who might be cured by the results of such research. But, to quote James Thomson, a leading researcher in the field, "If human embryonic stem cell research does not make you at least a little uncomfortable, you have not thought about it enough."

Some of the same arguments once used against experimentation with embryonic stem cells - for example, that it might result in deformations - are now being rolled out against the new, artificially created ones.

To quote a group of distinguished stem cell researchers, including the Japanese scientist who helped produce this new kind of stem cell, "We hold that research into all avenues of human stem-cell research must proceed together."

The debate over the uses and abuses of embryonic stem cells will doubtless get even more involved, but it's not about to conclude. For every Thou Shalt Not, there will always be those who, like the serpent, whisper: Thou Shalt!

Like stem cells, maybe that's part of human nature, too.

Paul Greenberg

Pulitzer Prize-winning Paul Greenberg, one of the most respected and honored commentators in America, is the editorial page editor of the Arkansas Democrat-Gazette.