Many well-intentioned pro-lifers have inadvertently adopted flawed or incomplete arguments while trying to defend the noblest of causes: the plight of the vulnerable and the unborn. In the debate over stem cells, for example, a common argument runs like this:

Human embryonic stem cell research is wrong because we are witnessing new medical treatments for sick patients exclusively with adult, not embryonic stem cells. Every disease that has been successfully treated thus far with stem cells has relied on adult stem cells, while embryonic stem cells haven’t produced any cures yet. Adult stem cells work, while embryonic don’t, and it’s basically a waste of resources to pursue something that is not working. Therefore scientists should stop beating their drums about human embryonic stem cells since all the real-life treatments for patients are occurring exclusively with adult stem cells.

This argument, often employed by those of a pro-life persuasion, is flawed on a number of counts.

First, it seems to presume that the only yardstick for determining embryonic stem cell “success” will be in terms of benefits to patients who are struggling with various ailments and diseases. Yet researchers themselves would argue that there are many other reasons to pursue embryonic stem cell research. For example, such research is sure to be valuable for gaining further insight into the cellular mechanisms underlying the development of an organism and is already providing important clues about how an animal builds itself up from a single starting cell called the zygote. Scientific research using non-human (e.g. mouse, rat, or monkey) embryonic stem cells can address these kinds of questions in a responsible way and clearly deserves to be funded and promoted. Such non-human embryonic stem cell research is, in fact, a praiseworthy and ethically uncontentious kind of scientific investigation.

Second, the argument that adult stem cells are helping sick patients while embryonic are not -- and thus the adult stem cells are “more ethical” -- seems to reduce the stem cell ethics debate to a discussion about what works best, or what is most effective. In fact, however, the ethical concerns have very little to do with scientific efficiency and everything to do with the fact that researchers violate and destroy young humans (who are still embryos) in order to acquire their stem cells.

Furthermore, it may be strictly a matter of time before the embryonic stem cells begin providing cures for human patients. At any point in the future, we could be greeted by a front page news story announcing a dramatic “success,” perhaps an embryonic stem cell transplant allowing childhood diabetics to give up their insulin injections or paralyzed patients to walk. That “success,” however, would not change the ethical objections to embryo destruction or make an evil act a morally acceptable one -- though it might increase the temptation for some to cross the objective ethical line.

To put it more simply: even if it were possible to cure all diseases known to mankind by harvesting (and therefore killing) a single human embryo, it would never become ethical to do so. We cannot choose evil that good might come, nor can we ever afford to pay the steep ethical price of ignoring the sacrosanct humanity of the embryo, that tiny creature that each of us once was ourselves. Treating a fellow human being, albeit a very small one, as a means rather than an end, violates his or her most basic human rights.

In fact, the direct killing of other humans, whether young and embryonic or old and in their dotage, is properly referred to as an intrinsic evil, meaning it is in every instance wrong, and ought never be chosen as a human act. Intrinsic evils do not admit of any legitimate exceptions. Once we concretely recognize the immoral character of an action prohibited by an exceptionless norm, the only ethically acceptable act is to follow the requirements of the moral law and turn away from the action which it forbids.

Bioethicist Paul Ramsey put it well in suggesting that any man of serious conscience, when discussing ethics, will have to conclude that, “there may be some things that men should never do. The good things that men do can be made complete only by the things they refuse to do.”

Refusing to destroy human embryos as a scientist does not imply any opposition to science itself, but only to unethical science, which, like unethical investment practices or unethical medicine, is invariably harmful to society. Good science is necessarily ethical science; it cannot ever be reduced merely to “efficient” science, that which might work or “solve my problems” at the expense of others. In arguing for ethical science, those of us working to safeguard human life would do well to examine our premises carefully, so as to avoid weak or questionable assumptions that could undermine the thrust of our arguments.

Rev. Tadeusz Pacholczyk, Ph.D. earned his doctorate in neuroscience from Yale and did post-doctoral work at Harvard. He is a priest of the diocese of Fall River, MA, and serves as the Director of Education at The National Catholic Bioethics Center in Philadelphia. See www.ncbcenter.org