No matter what side you're on in the Great American Abortion Debate, you'll find this article of interest. I discovered it this week in UU World, the Unitarian Universalist monthly magazine. It traces the history of religious practices around abortion, including the Catholic Church's radical change in 1917, driven by Pope Pius IX who said that centuries of previous Popes had gotten things wrong.
It's a fascinating read in terms of abortion rights, but it is also a cautionary tale about the enormous dangers of religious influence in public policy.
For most of the history of the Catholic Church, one did not become a human being or a person until well after conception. Saint Augustine in the fourth century adopted the Aristotelian belief that the human soul didn’t enter the fetus until forty to ninety days after conception. In roughly the same era Saint Jerome emphasized human shape: “The seed gradually takes shape in the uterus, and it [abortion] does not count as killing until the individual elements have acquired their external appearance and their limbs.” The Apostolic Constitutions of the late fourth century allowed abortion if it was done both before the human soul entered and before the fetus was of human shape. Saint Thomas Aquinas of the thirteenth century followed Augustine in not considering the abortion of a non-ensouled fetus to be murder. Pope Innocent III, earlier in the same century as Aquinas, emphasized that the soul enters the body at the time of quickening—when a prospective mother first feels movement of the fetus. When Pope Gregory XIV affirmed the quickening test for ensoulment in 1591, he set the time for it as 116 days into pregnancy, or the sixteenth week. The great reversal came with Pope Pius IX in 1869. He assumed ensoulment at conception, and by 1917 church canon law had been revised, dropping the prior distinction it had upheld between “animated” and “inanimated” fetuses. Pius’s position has been maintained by the Roman Catholic Church ever since.
By this reasoning, you'd have to conclude that god was asleep at the switch for more than a thousand years. Who knew.