A key point in debates about abortion restrictions is this question over when, legally-speaking, life begins. Some anti-abortion activists may suggest that after this point, abortion should no longer be legal. Many prominent anti-abortion voices have asserted life begins at conception, and argued it's backed by the science.
But there isn’t that kind of consensus scientifically or theologically. Scientific advancement has only made the question way more complicated, and a number of experts in religious ethics have pointed out there's as much disagreement and change as ever, even within a single religion. Just ask Margaret Kamitsuka, who’s been researching and teaching religious studies and gender for over 20 years.
"So the question of when life begins has always meant different things in different cultures and times," Kamitsuka said. "So it begins when the fetus gets its soul — everyone agreed on that, but there was no agreement about the timing. And that's where the issue is."
So let’s take a look at some of the theories for when life begins — some backed by science and some by faith. Because as the country braces for a wave of legal battles over abortion restrictions, it’s worth questioning some of these assumptions we’re going to keep hearing about what’s really “irrefutable” here.
First, let’s roll back the clock, all the way back to the end of medieval Europe. Back then, personhood was believed to start with “the quickening,” which was the first time a pregnant person felt a baby kick. That's usually around a little over four months into the pregnancy. Legal texts and midwife manuals pointed to that motion as a sign of personhood. Even the Catholic Church at this time didn't recognize abortion before the quickening as murder.
"So the only passage in the Bible that talks about a fetus in in any detail is in the Book of Exodus Chapter 21," Kamitsuka said. "If the fetus dies, then the perpetrator pays a fine. If the woman also dies as a result of the injury, then the penalty is for homicide. So the early church knew, of course, of this passage and accepted the principle that there is a difference in legal status between a non-viable fetus and a pregnant woman."
But over the 19th and 20th centuries, scientific advancement taught us more about embryonic development, and the debate began to shift. It wouldn’t be until as late as 1869 before the Catholic Church permanently declared all abortion to be a sin, which is its official stance today.
Does that sound like a consensus? Well, not so fast.
Contrary to popular belief, new research didn't actually bring us an "irrefutable” answer. Instead, the question got much more complicated. Part of that is because we now know many stages of development that have been argued to be “when life begins.”
In biology, first, of course, there is conception and fertilization. Some Christians point to certain Bible passages that imply this is when ensoulment happens. One can also point out that the embryo now has full genetic material, but it’s hard to say if that’s biological proof of life. Most cells in our body also have that, and those aren’t considered a separate life.
Two weeks later, we get to gastrulation. Now the embryo is biologically unique, so it can’t become twins or triplets. One could also argue this is the start of an “individual.”
At about six weeks, an ultrasound can detect a “flutter” of electrical impulses in the area that eventually controls a heartbeat. This is why proponents of abortion bans after six weeks call those laws “heartbeat bills.” But, as many in the medical community have noted, the name can be misleading since the heart isn’t yet fully formed.
Ask a neuroscientist when life begins, and they could point to about six months in, when we can start to see brainwave patterns. When we lose these brainwaves, a person is declared legally dead in the U.S. and many other countries, so some could argue brainwaves signal when a fetus starts being a person.
Around this time, the fetus can become viable outside the womb. That’s another legal milestone. In Roe v. Wade, the Supreme Court found the Constitution doesn’t let states ban abortions before this point. Keep in mind the point of viability is flexible, since it depends on what sort of clinical resources are available and how medicine has advanced.
Now, of course, roughly 40 weeks in, is the birth itself. The Jewish faith, along with some Christians, see this first breath as the beginning of life, and will point to other passages in the Bible to support this.
You can see why we just don’t have “biological proof” or even “religious consensus” when it comes to when life begins.
"The Roman Catholic Church does not specify when life begins," Kamitsuka said. "They say there's a presumption it's possible, and therefore we should never have it do an abortion, a direct abortion. But the Roman Catholic Church understands that even modern science cannot answer that question."
As our understanding of these issues has changed over time, so too have our laws around abortion and our feelings toward them.
Take the invention of the ultrasound, which was widely adopted in U.S. hospitals in the 1970s. Without the ultrasound, we wouldn’t even know about that little “flutter” that’s become the basis for the many so-called heartbeat bills we’ve seen get passed through state legislatures in the last three years.
The question of when life begins is always at the heart of these political battles, so it’s important to understand why that answer is so impossible to agree on. There seems to be only one thing that’s actually certain: the answer, as with life itself, is never so simple.