Disclaimer: I am neither a scientist nor a doctor. In this post I will lean heavily on those who are experts in those fields and do my best to represent them accurately.
Those who advocate for the position that abortion is murder from conception will often argue that earlier Christian positions differentiating between formed and unformed or animate and inanimate fetuses did so on the basis of faulty scientific understanding. “Now,” they argue, “the science of biology has answered the question beyond doubt: the unborn child is a living human being.” As you might have expected, in this post we’ll explore the reasons why that particular claim is an overstatement.
First, it is absolutely true that pre-modern Christians discussing abortion and related topics had faulty understandings of science. It is also true that many of these pre-modern Christians based their beliefs about abortion, life, and personhood on their erroneous understandings of embryology. This, however, is true of all premodern Christians, not just those who differentiated between formed and unformed or animate and inanimate fetuses. For example, Tertullian, who, as we saw in a previous post argued that abortion was murder from conception did so because he believed that, crudely speaking, the human soul was present in the semen of the male.
Second, it is also absolutely true that advances in scientific and medical knowledge have caused scientists and medical professionals to reconsider their positions abortion. For example, it was doctors in the mid-twentieth century who led the charge to regulate abortion when they came to understand that the previously prevailing notion of “quickening” was not, as had been assumed, a unique developmental milestone.
But does science answer the question “beyond all doubt” that human life begins at conception? Well, as it turns out, that depends on a lot of things, not least of which is who you ask and what you mean by “human life.” To begin to look for an answer, I’d like to turn first to Scott Gilbert, the developmental biologist we met in an earlier post. Widely regarded as an expert in the field, he has delivered lectures on the topic to audiences as diverse as the Vatican and Planned Parenthood. His textbooks on developmental biology are regarded by many as the gold standard in the field. It may also be worth noting that his wife is an OB/GYN. Gilbert has, at various times, directly addressed the question of when human life and/or personhood begins. In 2007 Gilbert presented an essay at a conference at the Vatican addressing that very topic. In the essay, he seeks to address what he believes to be a “syllabus of errors” in regard to popular scientific arguments made by the traditional pro-life crowd, arguments “that are often being told about embryos…that are widely accepted, but which science knows to be false.” Gilbert acknowledges that some of these errors have even “been supported, until recently, by eminent scientists and are repeated in introductory biology textbooks.” The essay is highly technical, but I will attempt to summarize his “syallbus of errors” here.
The first “error” Gilbert addresses is the idea that “the instructions for development and heredity are all in the fertilized egg.” He explains that scientists have come to understand that the environment is far more influential in gene expression than it was once believed. He also explains that in popular discourse, DNA has taken on an almost transcendent quality, functioning as “the secular analogue of the soul.” He notes the way pro-life organizations often appeal to the an embryo’s unique DNA as the basis for their assertion that that a fertilized egg is full human person. He explains that “while such a view might have been considered within the realm of scientific debate…in the 1970’s, this view of ‘genetic determinism’ is now known to be erroneous.”
The second error in Gilbert’s syllabus is the belief that “the embryo is safe within the womb.” Gilbert explains that there is a popular assumption that “under normal circumstances” a fertilized egg will always develop normally and predictably, leading to the birth of a baby. I’ll address this in greater length below when I discuss the problem of “pregnancy wastage,” but Gilbert demonstrates that, even apart from intentional abortions, the vast majority of fertilized eggs do not survive pregnancy.
Third, Gilbert debunks the claim that “there is a moment of fertilization where the passive egg receives the active sperm.” Popular among pro-lifers is the idea that “life begins at the ‘moment of conception.’” Gilbert explains that there is actually no such “moment.” Instead, he explains, fertilization is “a lengthy process that can take days to complete.”
The final “error” that Gilbert seeks to “disprove” is the notion that “there is a consensus among scientists as to when life begins.” Contrary to popular claims otherwise, he argues, “Actually, one of the few statements that can be made without any hesitation is that there is no consensus among scientists about when an individual human life begins.” He explains,
There are least four stages of development that different scientists have claimed as the point where personhood begins, including: (1) fertilization (the acquisition of a novel genome); (2) gastrulation (the acquisition of an individual physical identity); (3) electroencephalogram (EEG) activation (the acquisition of the human-specific…brain-wave pattern); and (4) the time of or surrounding birth (the acquisition of independent breathing and viability outside the mother’s body).
He then goes on to explain each viewpoint with references to scientists who have advocated for those positions.
There are, of course, developmental biologists who disagree with Gilbert, but, that’s actually the point. The “science” is not settled, and neither are the implications. The notion that “the science of biology has answered the question beyond doubt: the unborn child is a living human being” is, at best, a significant overstatement.
I’d like to turn now for just a moment to Jonathan Dudley, author of the book Broken Words: The Abuse of Science and Faith in American Politics, who was quoted earlier in an earlier post. Dudley is in a unique position to speak to this issue from multiple angles. Dudley grew up as an evangelical Christian, obtained a Bachelor’s degree in Biology from an evangelical university, a Masters in Religion from Yale Divinity School, and a Doctorate in Medicine from Johns Hopkins. After considering many of the very same historical and scientific arguments that we’ve seen here, he concludes that “science may illuminate human development, but it can’t answer the metaphysical question of when personhood begins.”
The Problem of “Pregancy Wastage”
One of the reasons some scientists and medical professionals have trouble with the idea of personhood beginning at fertilization is the prevalence of what has been called “pregnancy wastage.” Admittedly a crude term, “pregnancy wastage” refers to the spontaneous, natural abortion of an embryo fetus, also known as “miscarriage.” While the statistics vary, scientists tend to agree that anywhere from 50 to 75 percent of all pregnancies end in spontaneous, natural abortions. Some embryos/fetuses survive only hours, others days, others weeks, and others months, but at some point, for a host of reasons, the majority of them are spontaneously (not intentionally) aborted by the mother’s body.
As scientists, bioethicists, and others have noted, a 50 to 75 percent mortality rate in any other scenario would be regarded as a public health crisis of massive proportions. To put it in perspective, the Ebola virus has an average 50 percent mortality rate for those infected. Because of that, governments and health organizations the world over have invested and continue to invest vast amounts of resources toward treatment, prevention, and research. If the “pro-life” camp believes that every fertilized embryo is morally equivalent to a human being, you would think that they would be the loudest champions of research into natural embryo loss prevention. As Michael Sandel, Professor of Government at Harvard University observed,
If the embryo loss that accompanies natural procreation were the moral equivalent of infant death, then pregnancy would have to be regarded as a public health crisis of epidemic proportions; alleviating natural embryo loss would be a more urgent moral cause than abortion, in vitro fertilization, and stem-cell research combined.
This, of course, does not settle the argument of personhood – honest scientists admit that’s not a question science can answer – but it does highlight the ambiguity of the issue and perhaps the inconsistency of those claim to belief that life begins “at conception.”
Abortion and Medical Professionals
As I’m sure you’ve already predicted, the community of medical professionals is also divided over the issue of abortion. To illustrate the complexity, consider the fact that it was doctors who led the charge to regulate abortion in the mid-nineteenth century and then that it was doctors again who, in the twentieth century, protested abortion regulations as overly restrictive.
The American Medical Association, initially the champion of restricting abortions, now allows physicians to perform abortions “in accordance with good medical practice and under circumstances that do not violate the law.” The association also, according to one AMA spokesperson, “seeks to limit government interference in the practice of medicine and oppose government regulation of medicine that is unsupported by scientific evidence.” The American College of Obstetricians and Gynecologists, a professional organization with 58,000 members, asserts in its official opinions that “safe, legal abortion is a necessary component of women’s health care.” These are the very same people that we trust to care for our own bodies and the bodies of the ones we love, and deliver our babies.
Of course, not every member either medical organization agrees with the official stance of their professional organization. There are “pro-life” doctors and there are “pro-choice” doctors and there are doctors who hold positions somewhere outside of those binary positions. The point is, these organizations and doctors that we trust implicitly with so many other aspects of our healthcare recognize that abortion is ethically, scientifically, and medically complex.
In conclusion, there is no consensus in either the scientific or the medical community that abortion is murder. The very fact that such a diversity of opinions exists among these professionals should give us all pause when we hear the claim that “science proves” that human personhood begins at conception. As we’ll see in the next installment in this series, abortion is just as complex an issue legally as it is theologically, scientifically, and medically.
 Scott Gilbert, “When ‘Personhood’ Begins in the Embryo: Avoiding a Syllabus of Errors,” available at http://11e.devbio.com/ch/01/wt/0101/STOQ.Embryo.paper.pdf
 Dudley, Broken Words.
 Michael Sandel, “Embryo Ethics — the Moral Logic of Stem-Cell Research,” New England Journal of Medicine 351, no. 3 (July 15, 2004): 208
 American Medical Association, “Code of Medical Ethics Opinion 4.2.7,” https://www.ama-assn.org/delivering-care/ethics/abortion
 Quoted in “The surprising history of abortion in the United States” by Jessica Ravitz, https://www.cnn.com/2016/06/23/health/abortion-history-in-united-states/index.html
 The American College of Obstetricians and Gynecologists, “Committee Opinion #613,” Nov. 2014, reaffirmed in 2017, https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Health-Care-for-Underserved-Women/Increasing-Access-to-Abortion?IsMobileSet=false