While it is true that most professional philosophers do not find abortion morally problematic, as I argued previously, what about Christian theologians? I really don’t know or care much about the views of theologians, but certainly many Christians think they must oppose abortion on religious grounds. But must they? The answer is no for a number of reasons.
First, it is generally hard to find specific moral guidance in religious scriptures. They were written long ago, survived as oral traditions, have been translated multiple times, and are open to multiple interpretations. (Anyone who has ever translated from one language to another knows that literal translations are impossible.) Moreover, church traditions are ambiguous on many moral issues.
The key idea of the conservative view is that the fetus is a person with full moral rights from “moment” of conception. (There actually is no “moment” of conception, but that’s a different issue.) Most philosophers deny fetal personhood because the necessary or sufficient conditions of personhood are notoriously difficult to ascertain and, at any rate, the fetus does not satisfy many of the proposed criteria for personhood. The impartial view, backed by contemporary biology, is that a fetus is, at most, a potential person. But even if we allow for the sake of argument that the conservative view is the Christian view, this must be supported by either church tradition or church scriptures. But is it?
It is well-known that it is difficult to derive a prohibition of abortion from Christian scriptures, since the issue does not arise in there. There are a few Biblical passages quoted by conservatives to support the anti-abortion position, the most well-known is in Jeremiah “Before I formed you in the womb I knew you, and before you were born I consecrated you.” But, as anyone who has examined this passage knows, the sanctity of fetal life is not being discussed here. Rather Jeremiah is asserting his authority as a prophet. (This is a classic example of seeking support in holy books for a position you already hold.)
Many other Biblical passages point to the more liberal view of abortion. Three times in the Bible (Genesis 38:24; Leviticus 21:9; Deuteronomy 22:20–21) the death penalty is recommended for women who have sex out-of-wedlock even though killing the women would kill their fetuses. (I don’t think death is recommended for men who engage in this behavior, probably because they wrote the book.) Furthermore, in Exodus 21, God prescribes death as the penalty for murder, whereas the penalty for causing a woman to miscarry is a fine. In the Old Testament the fetus does not seem to have personhood status. Thus there is no strong scriptural tradition in Christianity against abortion.
There also is no strong church tradition against abortion. The idea that the fetus is a person from the moment of conception is quite new in church tradition. St. Thomas Aquinas, the preeminent thinker in Catholicism, held that embryo didn’t acquire a soul into several weeks into gestation—after the embryo had a human form. This position was officially accepted by the church at the Council of Vienne in 1312.
However, in the 17th century, scientists peering through primitive microscopes at fertilized eggs thought they saw tiny, perfectly formed people—what they called a “homunculus,” or little man. Now if humans had a human shape from the moment of conception then it follows, from Aquinas’ reasoning, that it has a soul from that time. This mistaken view of embryological development led to the Church changing its stand on abortion.
Of course we now know there is no homunculus. We know that embryos start out as a cluster of cells, and human form comes later. But when the biological error was corrected, the church did not revert to its earlier moral position. Instead it held to the position it holds to this day, that the soul enters the embryo from conception, even though this view is based on a false view of the biological facts.
The point of all this is not that the contemporary church’s position is wrong. For all I know, it may be right. My point is that the anti-abortion position follows no more from church tradition than it does from scripture. What happens when people suppose that religion demands a moral view is that they have a certain views and then look to scripture or tradition to support the view they already hold. People’s moral convictions are not usually derived from their religion so much as superimposed on it. All of this suggests that morality shouldn’t be based on religion, but on reason and conscience. As Plato argued long ago in the Euthyphro, things can’t be right just because the gods command them, the gods must command them because they’re right. And if that’s the case then the gods have some reason for their commands, reasons that are intelligible to rational beings.
Thus we are led back to philosophical ethics. In the case of abortion, rational arguments either support the anti-abortion position or they do not. The vast majority of professional philosophers find those arguments seriously lacking. I agree. The arguments for the pro-life position are seriously deficient, while the opposing arguments are philosophically robust. On that basis I concluded years ago that abortion was almost never morally problematic.