The Supreme Court will weigh just how easy it should be to obtain an abortion on Wednesday when they hear Whole Woman’s Health v. Hellerstedt, the most significant abortion case since 1992.

The question at the center of the case is not whether abortion is morally right or wrong, per se. It’s whether Texas has the right to place certain restrictions on abortion—specifically whether it can require abortion clinics to meet the same standards as a surgical centers and to only employ doctors who have hospital admitting privileges within 30 miles of the clinic. If these rules are allowed to go into effect, there would only be 10 abortion clinics left in Texas, a state that’s larger than the country of France. Already, about half the state’s 40 abortion providers have closed their doors.

Advocates of the restrictions say they help make abortion safer for women. But last year when I interviewed the lobbyists who helped write the rules, a group called the Americans United for Life, they suggested they would support limiting access to abortion because it is, at its core, a terrible practice.

The modern abortion debate can feel like trench warfare, with diametrically opposed camps and very few defectors. Surprisingly, though, even the history of abortion is contentious. It’s widely known that there was a legal crackdown on abortion in the U.S. in the 19th century, and clandestine abortions persisted until the practice was legalized with Roe v. Wade in 1973. But scholars don’t agree on whether, before the 1800s, abortion was relatively common and legally accepted, or whether it was considered a grave crime, when it happened at all.

This is no idle academic spat. English common law provides the basis for much of the legal precedent in the U.S. (and elsewhere in the former British empire.) More importantly, in his majority opinion in Roe v. Wade, Justice Harry Blackmun cited the historic acceptability of abortion. It is “doubtful that abortion was ever firmly established as a common law crime,” he wrote.

Carla Spivack, a scholar of the law and English literature at the Oklahoma City University School of Law, argues that dating back to the 14th century in England, many sources suggest abortion was not considered illegal before the point of “quickening,” or when the woman was able to feel the child move in her womb. This usually occurred at about four months, or 16 weeks of gestation. Even after quickening, abortion was typically judged a misdemeanor at most. Women who wanted to terminate their pregnancies used various herbs and tinctures, and the effects of these potions were well-known among midwives.

Meanwhile, a Villanova University law professor named Joseph Dellapenna claims the truth is just the opposite in almost every way. He says abortion was consistently criminalized in England since roughly 1200. According to him, prosecutions for abortion have been happening for centuries, usually out of concern for the unborn child. He’s laid out his thinking in a book and in several briefs in high-profile Supreme Court cases on abortion.

In a rebuttal to Dellapenna published in the William and Mary Journal of Women and the Law in 2007, Spivack argues that when abortion was prosecuted, it was mainly done as a way of either cracking down on illicit sex or punishing a man who injured a pregnant woman. (Dellapenna says many abortion attempts were, in fact, prosecuted as witchcraft.) Authorities at the time were more concerned about prostitutes and vagrancy than they were abortion, Spivack writes, and the state had little say in what happened between married couples. For example, in the aftermath of one abortion in 1742 in Connecticut, as explained by the historian Cornelia Hughes Dayton, there seemed to be just as much concern over the fornication that took place as there was about the destroyed fetus.

“This is why [Dellapenna] hates me,” Spivack said, perhaps only half-jokingly.

According to Spivack, the Anglo-Saxons, the people who inhabited Great Britain from the 5th century, believed that the soul entered the body during quickening. “The baby moves, and it displays an ability to be animated,” she said. “They thought that was what having a soul meant.”

And of course, medical thinking at the time was a bit more ... imaginative. Bodies were thought to be ruled by humors, and Spivack argues that some miscarriages were considered a normal type of purging, not unlike bleeding. Midwifery manuals from the 17th century speculate that before quickening, it’s impossible to know whether the fetus is even human. “[M]onsters of all sorts [can] be formed in the womb,” wrote one such midwife. In addition to human children, women could also become pregnant with “false Moles,” or non-sentient lumps of flesh and veins. Quickening was the only way to know for sure if you were pregnant—and what with.

As further evidence, Spivack points to recipes for concoctions, made from things like ergot and savin, that would “bring down the flowers,” a euphemism for restoring menstruation. Sometimes, women would take the herbs if they were missing periods because of nutritional or other health issues. Other times, though, it was meant to cause a miscarriage.

Dellapenna argues, meanwhile, that herb-based abortions were tantamount to suicide. They worked by poisoning the fetus, but took down the mother, too. “Women are not fools!” he said. “They said, ‘I’ll wait till the baby is born.’” Thus infanticide, helped along by complicit midwives, became a much more endemic problem, in his view.

(Spivack says that to the extent infanticide happened, it was mainly a phenomenon among single women. One centuries-old law stated that a woman found alone with a dead baby should be presumed to have killed it.)

Leslie Reagan, a professor of history and women’s issues at the University of Illinois, takes Spivack’s side. Her book, When Abortion Was a Crime, came out in 1997. In a review for The Atlantic at the time, Katha Pollitt wrote that it dispels the notion that “widespread use of abortion [is] a modern innovation, the consequence of some aspect of contemporary life of which [opponents] disapprove (feminism, promiscuity, consumerism, Godlessness, permissiveness, individualism).”

Reagan says many women would dose themselves with abortifacients but stop once they reached quickening. In the 18th century, “there was even a term for it, ‘taking the trade,’” Reagan said in an interview. “Peddlers would go from town to town selling various herbs and powders that would induce a miscarriage.”

In England, abortion became criminalized in the early 1800s, and U.S. laws quickly followed. Again, according to Dellapenna, policymakers at the time were concerned about child murder.

Reagan and others, meanwhile, believe criminalization was driven by fears that wealthy, white women were having too many abortions, therefore depriving the country of badly needed people. During this time, Reagan said, “abortion” was chosen to represent any terminated pregnancy—even those before quickening.

The fear at the time was, “women are not doing their duty, and if they don't bear the fruit of their loins, who is going to settle the great vast prairies?” she said.

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So why does it matter what the Anglo-Saxons thought about fetuses? Any number of things from the past—witch-hunts, slavery—are thankfully no longer part of legal thinking. Why should we care about the history of abortion?

Spivack acknowledges that looking to the Anglo-Saxons might be digging too deep. But our modern theories of right and wrong come from many sources, and a big one is English common law. “The people who wrote about the law in 17th, 18th, 19th centuries—Matthew Hale, William Blackstone—we read them today,” she said. “If they say this, we have to take it seriously.”

For his part, Dellapenna acknowledges that if the Supreme Court justices take his view that abortion has not historically been smiled upon, and in turn leave abortion restrictions up to the states, abortion would be all but unattainable in some parts of the country.

“This would discriminate against poor women. This would be a problem,” he said. But the practical consequences are beyond his purview. “I’m just the guy who’s after the truth of the matter.”