I had the dubious distinction of graduating from high school in 1973, the year Roe v. Wade and Doe v. Bolton where handed down by the Supreme Court, giving the U.S. the most permissive abortion policy in the Western world. I remember well the question everyone was asking at that time: “When does human life begin?” 

Justice Harry Blackmun famously wrote in the court’s majority opinion, “We need not resolve the difficult question of when life begins. When those trained in the respective disciplines of medicine, philosophy, and theology are unable to arrive at any consensus, the judiciary, at this point in the development of man’s knowledge, is not in a position to speculate as to the answer” (p 159). For decades, the abortion debated hinged on the answer to that question. 

Today, no matter what their view on the legality of abortion, every informed and honest person agrees that an individual human life begins at conception. The science is settled. When half the chromosomes from a woman’s egg line fuse with the other half from a man’s sperm, a new, genetically unique human being comes into existence. To be exact, at least one genetically unique human being comes into existence, because twinning is still possible at that point.  So, human life begins at conception.

We’ve known the science for a long time, but the implications have become clearer over time. For instance, the debates in the early 2000s over human embryonic stem cells actually helped to clarify the debate about abortion. For a long time, the debate about abortion was ostensibly as much about a woman’s body as about the destruction of an embryo or fetus. Abortion was justified, and still is by many, on the basis of a woman’s right to control what happens in her body. The fetus is in her body, so the woman has a right to have it removed, even if doing so results in the death of the fetus—or so the argument goes. 

With the human embryonic stem cell debate, the woman’s body was removed from the equation. The light was shown like a laser on the living human embryo. Human eggs and sperm were retrieved from donors, fertilized in a petri dish, and coaxed to develop in vitro (literally, in glass). The debate about human embryonic stem cell research was never about “when human life begins.” Everyone knew that the eggs were from a human female, the sperm from a human male, and the result was living human embryos. Dead embryos would not work for research purposes. And the scientist doing the research did not want dog embryos, cat embryos, or even mouse embryos. They wanted human embryos, and that’s what they got. Living. Human. Embryos.

The question of personhood

How, then, can someone who believes that human life begins at conception justify abortion or even human embryonic stem cell research? Because the question has been reframed. Of course the embryos are clearly human, and of course these tiny humans are clearly alive, but they are not persons. The argument shifts then. Yes, persons have a right to life—a right not to be unnecessarily harmed—but, the argument goes, human embryos are not yet persons. Only persons have a right to life. 

When does personhood begin?  That is the question now. Or to put it another way, are embryos persons? Are fetuses persons? For that matter, are newborns persons?  

In a seminal essay on abortion, reprinted in nearly every introductory anthology on ethics, philosopher Judith Jarvis Thomson posed a hypothetical. Suppose, she said, you awakened one morning to find that someone had surgically connected your kidneys to a world-class concert violinist in order to preserve the ailing violinist’s life. This will mean that you might be confined to a bed for nine days, nine months, or nine years, depending on how long he lives. Thomson asked, “Are you morally obligated to maintain the connection?” 

She then embarks on a very interesting, if convoluted, journey to try to demonstrate that you only have a very minimal obligation to sustain the life of the violinist if doing so does not cause great inconvenience to you. Even though she is willing to grant for the sake of the argument that a fetus is a person, at the end of the essay she reveals her own view of the moral status of the unborn human being. “At this place, however, it should be remembered that we have only been pretending throughout that the fetus is a human being from the moment of conception. A very early abortion is surely not the killing of a person, and so is not dealt with by anything I have said here.” Case closed. Fetuses are not persons, according to Thomson. So, is no harm done in killing “it”? No, to be accurate, the fetus is a him or her. Even our language signals that fetuses are gendered persons. 

What is personhood? Or, better, who is a human person? Human persons (in contrast to divine and angelic persons) are individual members of the species Homo sapiens. Rocks are not persons, plants are not persons, and animals are not persons, despite efforts to grant great apes, dolphins, and other animals personhood status. In theological terms, a human is someone made in God’s image and likeness (Gen. 1:27). 

In Genesis 9:1-7, God makes a distinction between animals and humans, giving Noah and his family permission to kill the animals for food, but prohibiting the unjust killing of another human being because humans alone are made in God’s own image. The image of God, the imago Dei, is the basis of human exceptionalism. Although there are various theories about just what constitutes the image of God in humanity, it’s clear from Scripture that human beings alone are made in God’s image.

Human beings—imagers of God—are persons from conception. This is clear in passages like Psalm 139:13-16 (HCSB):

For it was You who created my inward parts;
You knit me together in my mother’s womb.
I will praise You
because I have been remarkably and wonderfully made.
Your works are wonderful,
and I know this very well.
My bones were not hidden from You
when I was made in secret,
when I was formed in the depths of the earth.
Your eyes saw me when I was formless;
all my days were written in Your book and planned
before a single one of them began.

David, the psalmist, acknowledges God’s intricate handiwork in the womb. He also realizes that God knew him as a person before he was born. The real questions today, then, are who counts as persons, and what are our obligations to persons? If every member of the species Homo sapiens is a person, then we have certain obligations not to unnecessarily harm other human beings. The unjust taking of the life of an unborn human being is a harm. Therefore, abortion is wrong because it is the destruction of a human person.