What Does It Mean to Be Human? Bioethicist Laurie Zoloth argues that life is a complex process that unfolds temporally, physically and spiritually, and that the prospect for medical cures can be balanced against the destruction of an embryo.

What Does It Mean to Be Human?

Of all the mysteries that surprise and delight us, surely the process by which a human being is created is the most ordinary and the most mesmerizing. In the last three decades, this process has also raised ethical questions that have defined and divided Americans: When does human life begin? What does it mean to be human?

Our answers to these questions shape the debate over the use of human embryonic stem cells to understand and hopefully to cure human diseases. If life begins at the instant of conception, then any act to end that life would be wrongful killing. But if human life is a contingent matter, a slow and complex process that unfolds temporally, physically and spiritually -- as I believe -- then it is possible to speak of times and manners and reasons why other moral appeals may matter more.

About the Author

Laurie Zoloth is a professor of medical ethics and humanities and of religion at Northwestern University. She is the past president of the American Society for Bioethics and Humanities.

We are more than our DNA maps, for we are our love, our chance for duty. Careful use of the human blastocyst may be seen as a basic human duty in the face of significant suffering. These are the reasons why people of the deepest faith all over the globe support and defend stem cell research.

For the Other Side

For most of human history, pregnancy was understood as prelude. Life was understood to begin in stages, the most important one being the birth itself, when a person becomes fully human, accepting the blessing of human family and community and attaining moral status for the Greek philosophers such as Aristotle.

For the writers of the first texts and laws of Western religions -- Christian, Jewish and Muslim -- pregnancy became actual when it was tangible, visible or palpable to the outside world. For them, the soul -- God's participation in human beings -- needed a form.

It was only after microscopes could reveal egg and sperm that such a concept as "life begins at conception" could alter theological and legal traditions, and in part, this is why the Vatican changed its idea about when life began. Prior to the mid-1800s, the Roman Catholic tradition, like Jewish and Muslim law, followed the science of Aristotle -- that the first 40 days after conception was "formless" or "like water." Catholic canon law changed to reflect this new policy and the new science in 1917.

We know now that much has to occur for fertilization to take place. The egg must be released, it must accept the sperm, the cell wall and the nuclear wall have to be breached, the DNA correctly assembled. Even more has to occur before we can claim a woman is pregnant: The fertilized egg -- a blastocyst -- must maneuver the fallopian tube, get to the womb and be implanted. Only then can a pregnancy test confirm the event.

All along the way to birth, there are critical biological events, a universe of chance and contingency. That is why we greet each child as a miracle. That is also why we question the fate of the hundreds of thousands of human blastocysts created to treat infertility and then left in labs around the world.

Beyond the question of life's biological beginning, we need also to decide when our moral obligations to others begin -- in this case, to others who suffer and whose own lives are at stake.

As a society, in our treatment of infertility, we have already made the decision that it is just and right to treat serious disease by researching and then creating human blastocysts. We allow physicians to experiment on human sperm and human eggs to find the best way to make blastocysts, to make far more than the couple will be able to use, to implant them knowing that only one or two can be carried to term.

We have been making blastocysts in the lab for more than two decades, knowing that most will be destroyed routinely. At stake is whether we can use blastocysts made in this way to treat other diseases, like diabetes, Parkinson's or spinal cord injury by using them to make stem cells.

We have our duties toward all of life, to be certain. We have duties toward the uncertain microscopic world, duties toward the blastocysts we create. But we have duties as well toward the millions of patients who might be cured by regenerative medicine, just as we did toward infertile women.

It is the strong belief in many religious and philosophic traditions that the ethical appeal for healing the suffering neighbor is far more important than the appeal for the blastocyst.