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In order to provide Fox News Web site users with a better understanding of the ethical and moral debate surrounding stem-cell research, the editors and research department at the Fox News Channel prepared the following primer.

The Case Against Stem Cell Research

Opponents of research on embryonic cells, including many religious and anti-abortion groups, contend that embryos are human beings with the same rights — and thus entitled to the same protections against abuse — as anyone else. They believe life starts at the moment of conception, when a sperm fertilizes an egg, since a distinct organism has come into being. Thus the destruction of an embryo is the destruction of a human life.

Anti-abortion groups also oppose research on stem cells derived from aborted fetuses. They reject the argument that since abortion is already legal and women will have them, that stem cells should be used from aborted fetuses because they would otherwise go to waste.

Pope John Paul II has offered one argument designed to address just these sorts of questions when he wrote:

"Experience is already showing how a tragic coarsening of consciences accompanies the assault on innocent human life in the womb, leading to accommodation and acquiescence in the face of other related evils, such as euthanasia, infanticide, and most recently, proposals for the creation for research purposes of human embryos, destined to destruction in the process. A free and virtuous society, which America aspires to be, must reject practices that devalue and violate human life at any stage from conception until natural death."

But other critics of stem cell research support research on aborted fetuses, since those fetuses are already dead, yet oppose the destruction of embryos, because they consider the embryos to be alive — or at least have the potential to become a human being.

Some groups that do not oppose abortion are uneasy about the prospect of studying tissues derived from aborted fetuses or discarded embryos. For example, the United Methodist church supports abortions rights, but opposes the research industry's demand for embryos.

Many ethicists and scientists also oppose embryonic research. In a July 1999 statement, 100 bioethicists, scientists and legal scholars said they objected to embryonic stem cell research on the grounds that such research is both unethical and unnecessary.

Some of these critics argue that recent research showing that adult stem cells may be more versatile than previously thought, say scientists may soon be able to derive stem cells from adults.

Those who are opposed to this research also believe that their tax dollars should not go to supporting the research regardless of whether or not the research is permitted.

The Case for Stem Cell Research

Most critics of the embryo research ban contend that week-old blastocysts are not human beings, and that destroying those embryos does not constitute killing. At one week, embryos are merely a cluster of cells and not deserving of the protections afforded to others, they say. When conceived naturally, a blastocyst has not been implanted in the uterus by that time. Most scientists argue that an embryo is not a person until it is at least two weeks old, when it develops a so-called primitive streak, the first evidence of a nervous system.

A number of religious groups support embryonic stem cell research, and many Protestant sects and most Islamic and Jewish theologians also do not consider a young embryo to be a human being.

Some critics of an embryo research ban point out that funding is already permitted for research on more advanced, aborted fetuses. Advocates of embryo research say that the potential medical benefits of the research outweigh moral concerns about the embryo.

They worry that a ban might cut off scientific opportunities "to those most qualified to make dramatic advances towards using stem cells for the treatment of disease," according to one group in favor of the research.

Further, supporters of the research argue that federal involvement would increase the pool of talented scientists who could study the cells, and thus accelerate the pace of the research.

Lifting the ban on research would also, they say, allow the government to gain better oversight of embryonic research; studies conducted with federal funds are subjected to rigorous peer review and ethical oversight, while private research need not follow such standards. Thus the oversight could lead to restricting research that lawmakers find objectionable, such as studies that attempt to create human clones, for example, although many supporters of stem cell research also favor cloning research.

Federal funding advocates say stem cell research will continue with or without government funding, and say that the government should regulate that research — especially since they believe information about advances in stem cell research should flow freely into the public domain.