The idea of when personhood begins and ought to be respected is a sort of Zeno’s Paradox —like how many hairs it takes on someone’s face before they have a beard.
We have a commonly understood idea we all agree on, but defining the exact moment where something crosses over is always absurd and any given number of people will have different, contradictory, even self-varying opinions on where they draw the line.
If you say that someone with 3,017 chin hairs is still beardless but 3,018 has a beard, that’s ridiculous. But it’s also ridiculous to say that the first hair on someone’s chin is what makes them bearded if you want that concept to have any utility and align with anyone’s intended meaning.
The standard that life begins at birth is arbitrary and ridiculous. But it’s also clear, much more clear than basically any other dividing line we have because it’s a physical, spatial delineation.
On an ethical level, how is it worse to kill a 10-day-old infant than terminate a 35-week old fetus, especially if the infant was born two months prematurely? And the answer is that by any rational, objective measure it isn’t worse, but legally we need some point of division and birth feels much less arbitrary than some number of hours or days outside the womb.
It sounds obscene, but if you support abortion at any point inside a woman, why should it not still be ethical to allow parents to euthanize newborns outside the womb, especially if the infant has realized their worst fears of a congenital illness, an illness likely to cause great suffering?
Again, the slope is slippery here on what counts as a valid justification. An infant born with anencephaly, sure. But Harlequin-type ichthyosis? A handful of people have survived into adulthood, but many more have died after a lifetime of agony and none without the advantage of enormous medical resources. Down Syndrome? ALS?
We need laws to seem like they are absolute and make sense even when under close scrutiny they don’t because laws are products of consensus and we all have to assent to them for society to function.
That’s why most people who would be horrified at an abortion at any stage of pregnancy, or even reject contraception outright—much less a late-stage abortion and infant euthanasia—have no problem eating a pig that was horrifically mistreated its entire life and brutally slaughtered, despite that pig having a far far greater capacity for experiencing suffering and actually being much more abused than a hypothetical ‘end-of-life’ procedure would entail for an infant, fetus, or zygote.
The pig isn’t human, so we can easily define it as non-human, not deserving our concern or respect, much more easily than if we tried to create a rational ethical standard that included capacity for suffering and pain, because then we have to get into the business of counting hairs. The distinction between a pig’s suffering and a human’s is the difference between a fetus in the womb and a baby outside it. It’s clear and obvious even if the basis for that distinction is not, like in the above images of a pig’s fetal development.
If humans have something unique about us that isn’t found in other animals or extinct hominids, I’m not aware of any examples or empirical evidence pointing to that. Art, song, tool use, creativity, language, consciousness, empathy, domestication, agriculture—we can find parallels in other primates, corvids, cephalopods, cetaceans, or ants. There isn’t anything uniquely notable or precious here.
The question is where is it most useful to draw a line on where it’s acceptable and unacceptable for someone to end a potential life they created without the government’s consent being required, and I think there’s a defensible position for anything from 28 weeks up to still-hospitalized post-birth. Any earlier and you run into common spontaneous abortions/miscarriages and undiagnosed congenital defects; any later and there’s no way to differentiate from malicious infanticide.
But the most obvious, inarguable (still completely arbitrary!) dividing line is birth itself, and we use it because it does more good than harm to respect women’s autonomy all the way up to this point, even if it includes some mythical sociopaths who suddenly change their mind in the 40th week and spitefully wish to see their healthy fetus terminated as close to birth as possible.
Even supposing some number of the 1.3 percent of abortions that occur after 21 weeks actually involve such people, that has to be weighed against the women who wish to give birth to a healthy baby but would have to risk their lives without any such guarantee, or fetuses that are guaranteed not to survive beyond a few hours of intense suffering and natural death, or sexual assault victims—including children—who couldn’t get access to care before that.
There is a trade-off to these things. Early on, the restrictions you put on a fully realized human life greatly negatively affects it and still does relatively little harm to potential lives and a societal appreciation for life. Later, that changes. Zygotes don’t register on the scale of concern while born-infants immediately start to tilt trade-offs toward them and general social attitudes.
You’re always counting hairs. It doesn’t resolve the conflict to approach it that way, but like most disagreements including gun rights, public security, taxation, and civil liberties, there is a range of broad consensus, and the problem is law has to say this many hairs makes a beard and any fewer doesn’t. Absolutism treats which hair as sacrosanct, instead of recognizing that it’s a difficult problem with mutually exclusive positives and negatives.