There is a simple beauty to the standard pro-life argument against abortion. A transcendent entity (usually the Christian God) proclaims a universal (applies across the temporal as well as the spatial universe) ethic to a privileged group (humans) in order to protect a vulnerable subset of that group (pre-birth humans) from the instant of their creation (conception) until the instant of their transition (birth). Similar ethics apply after birth, of course, but the focus here is prior to that point.
There’s really very little to argue with, here. If you accept the premises, the conclusions follow smoothly, and the clear demarcations at conception and birth allow for very little ambiguity in interpretation. The only tricky issues given this ethical stance are social; what puts a woman in a position where an abortion is desirable? What support systems (economic, social, psychology, etc) are present for her to carry the baby to term? What happens to the children born thus?
Unfortunately, the premises are not without their problems, and changing just one premise slightly can throw the entire stable belief system out of whack. And the picture given above isn’t just a little off; most of the premises are ill-founded or mere assertions. It’s unlikely that there is a transcendent entity, although that’s fundamentally unprovable - to insist otherwise is an assertion either without evidence or in many cases, in spite of evidence to the contrary. With or without such an entity, the existence of a universal law (whether a literal divine mandate such as shari’ia or something more like utilitarianism) has thus far proven elusive to the most competent philosophers. If such a universal ethic exists, it’s not universally agreed upon, which makes its implementation and enforcement a problem of history and politics more than ontology.
Presenting humans as privileged animals panders to our feelings of self-importance, but most evidence points to humans as being different in degree, rather than kind. This is most stark when comparing the foetal human to other animals. This confounds the later questions, as well; a foetal human is less sentient than an adult chimpanzee, so if the human difference is defined as “sentience”, then certain nonhumans will rank as more sentient than certain humans. Similarly, if the fact of life itself is not sufficient to determine the ethic, then the clean boundary that conception presents is replaced by a more hazy boundary defined by sentience, capacity for sensation, sapience, degree of dependence, and any number of other facts - all of which are terribly difficult to identify, harder to define, and next-to-impossible to agree upon.
As an aside, much of the rhetoric on the pro-life side uses “innocence” as a qualifying factor - confusingly, as the doctrine of original sin seems to negate this possibility, but perhaps it serves the purpose of minimizing the cognitive dissonance involved in simultaneously supporting drone strikes and capital punishment.
Given all these problems with the common pro-life prior assumptions, many who self-describe as pro-choice respond by artificially narrowing the complexity of the problem. This simplistic examination opens itself up to attack, and deservedly so. Human life is still assumed to be exceptional, but “human” is defined as beginning at some point between conception and birth (or in rare cases, after birth). The implication is that we need have no moral concern for the nonhuman.
Additionally, there is a disavowal of the actual action; even when a pro-choice activist acknowledges an ethical divide (up to the third trimester abortion is okay, but not afterwards) the far side of the divide is described as problematic but rarely as murder or manslaughter (or whatever the relevant legal distinction is). After all, it’s impolitic, seen as catering to their political opponents.
“When is it clearly not okay to terminate a gestating human life?” is a question that those who are willing to consider beyond mere assertion will likely disagree on forever. Nevertheless, I think there are inroads where consensus may be formed generally, if not on the specifics.
For one thing, most people agree that less abortion is better, particularly late-stage abortion. At the one extreme, very few people (thankfully) will say that infanticide is not immoral, and agreement on which point it ceases to be immoral grows as you trace the process backward through the third trimester, to the second, to the first. When you reach the point just prior to conception, the only folks remaining on the immoral side of the fence are those who oppose all forms of birth control, “seed-spilling” and the like. So while you may never be able to please everyone, there are opportunities for a broad consensus on keeping the abortions that happen as near conception as possible, and emphasizing pre-conception preventative measures.
What causes a gestating human to “achieve personhood” in the moral or legal sense varies; some say its tied to the capacity to feel pain, others to sentience or even sapience, others to to the capacity to have desires and intentions. Perhaps it’s an emergent property of dozens of factors, any one of which may be absent but when a critical mass arises the personhood becomes recognizable. In that last case, it becomes impossible to make a clear distinction except at the extremities.
This inscrutability should inspire a conservative response; if it’s not clear whether you are dealing with the possibility of ending the life of a person (however defined), or not, the default should be to avoid actions that would endanger that person. When this person’s further growth endangers the person carrying them (the mother), the party best equipped to answer the dilemma would be the mother herself.
There are a few interesting implications, here. The first is that if the divide is no longer conception but “personhood”, the unexceptional nature of humanity means that the same ethical imperative occurs regarding the killing of other species who meet the same standard. It is here that animal rights activists and pro-life activists should find common cause, and indeed some already recognize this, as shown in this essay by Andy Alexis-Baker, who is exploring a posthuman Christian ethic for life:
We must see the incarnation is not that the Son became human, but that the Son became flesh: that is, God became a creature. That is the widest horizon within which to see the incarnation.
Additionally, since the clarity increases the nearer to conception we get, the emphasis on action should be similarly weighted, with access to educational resources, means of prevention, early-information and early action encouraged and made available as trivally and at as low a cost as socially possible. Even more broadly, it behooves society to examine the broader causal factors of problematic or undesired pregnancies, and address these at their roots, be they cultural attitudes, familial instability, economic insecurity or what have you.
That brings up the second major ethical dilemma that is too often elided in these discussions, which is the relationship between the individual and society. In the starkest variant of the narrative that all abortion is murder, society has a clear role: to protect the potential victims, and to prosecute the guilty. In the more illegible narratives, collective actions become less clear as well. For myself, it makes sense to have laws that restrict abortions to a certain stage of pregnancy, with exceptions only made for medical emergencies; the gap between conception and the legally-mandated bound ought to be policed with the aforementioned means of education, prevention and cultural support for the women involved - encouraging them through the pregancy and providing medical and fiscal support to encourage this, offering adoptive parents when necessary, discouraging abortions as the pregnancy progresses, and whatever else makes sense. In prosecuting cases of the laws against late-stage abortion, care should be made to focus on making the consequences strong disincentives rather than punishments.
Some of the most clearheaded writing on the subject has been by Alonzo Fyfe (creator of the moral system of desirism), who wrote the ethics of abortion and infanticide at his blog several years ago (part 1, 2).
More generally, John Michael Greer writes of ethics:
Test every choice against the requirements of whole systems, the necessity of flow, the inevitability of balance, the reality of limits, the nature of cause and effect, the relationship among the planes, and the process of evolution, and you will find that any decision that makes sense when measured against these standards will be both the ethical choice and the effective one.
Finally, David Sessions kindly emailed me a PDF of Kristin Dombek’s phenomenal piece on “The Two Cultures of Life” in n+1. It’s a story of growing up as an anti-abortion activist, converting to an animal rights activist, and comparing the cases of Scott Roeder and David San Deigo. I’ve posted some excerpts here, and you can purchase the digital version of issue 10 at the n+1 shop.