Tuesday, October 17, 2006

Recap: When does an embryo have a soul? - by Elissa McCormack

Saint Thomas Aquinas believed in what today is called “delayed hominization,” i.e., that the embryo has first a vegetative soul, then a sensitive soul, and it is only later that the embryo actually has a human soul. There are also two definitions of Thomas’s soul that we have to keep in mind: first, the soul is the substantial form of the body (so a human soul is what makes a human to be a human), and second, a soul could not be united to a body unless the potency of the body were disposed by its present form to be actualized by the human soul (there has to be a sufficient amount of organization to support the soul). However, Thomas’s theory is based on outdated biology, so we need to look at what his theory would look like when it is informed by a modern understanding of biology.

During the process of fertilization, the embryo receives its genetic structure, unique from that of the mother or the father, and then cell division begins. However, according to Thomas’s idea of the soul, we cannot say that the embryo has a human soul at this point because there are no structures in place to support the higher functions of the human soul, i.e., the intellect and the will. In fact, the brain is the last organ to develop and continues to develop until two years after the birth of the child.

Another problem with saying that the embryo has a soul at this point is the issue of twinning. Although with the genetic code the embryo is set to develop into a human being, at this early point in the pregnancy any cell that divides from the other cells has all the genetic material to develop into an entirely new human! Since an individual human soul cannot divide, the idea of an individual human being splitting into two human beings is kind of hard to take. Additionally, one-third to one-half of all fertilized eggs do not survive to implant. If the embryo is given a soul by God at the “moment” of conception, what happens to all these souls?

The interesting thing about implantation (ten to fourteen days after conception) is that this is the point when the possibility of twinning is removed and then the nervous system and the heart first begin to develop. I think that if we are using Saint Thomas’s idea of the soul, this is the point when God would infuse the embryo with a human soul. There is also no longer any chance of this “human” splitting into more than one human through twinning. Additionally, since the cells that make up the nervous system and the heart are beginning to differentiate themselves, this is also the first moment in the pregnancy that you can argue that the embryo has even the beginnings of the structures necessary to support the rational functions of the human soul.

What does this mean for the teaching of the Catholic Church? Not much actually. Since implantation is really the first moment that a woman can know that she is pregnant, the teaching on abortion would not change. Additionally the teaching on the morning-after pill would not change because, properly speaking, that pill is classified as emergency contraception and so would be covered under the Church’s teaching on contraception. The only teaching that might have to change (and I welcome comments on this issue because I am not as informed about it) is that on stem-cell research. The question as I see it is: what is the moral status of the artificially fertilized eggs that are never intended for implantation? If the human soul is connected to implantation, these eggs would not have moral human personhood.

However, since science cannot teach us morality, in this issue we need to turn to the certainty we get from faith and the teachings of the Church. Both John Paul II’s Evangelium Vitae and the Congregation for the Doctrine of the Faith’s Declaration on Procured Abortion teach that since we do not know when the embryo receives a human soul, it is better to respect the life of the embryo than it is to risk the sin of murder.

5 comments:

Anonymous said...

For the curious, here is the easiest place to find Thomas' thought on the subject: Ia qq. 118 and 119.

Also, here's an interesting argument for immediate hominization from Thomistic principles.

The crucial distinction this article makes is that the "matter proportioned to the form" need not be in fully formed organs, but may be in the unique genetic code formed in the fertilization of the ovum. I'm not sure how this jives with Thomas' progression from vegitative to sensitive to rational soul. (Does Thomas see these as three distinct souls? Or does he see them as the progressive actualization of a single, unique soul?)

Anyway, thanks Elissa for your talk!

Anonymous said...

At your talk, you mentioned that Catholic teaching did not state that abortion was "murder" until relatively recently in history.

I think this question is murkier than that. (I'm referring solely to the question of how the terminology has been used historically -- not to anything else.)

We need to distinguish between three different things:

1. The spontaneous delivery/expulsion of an embryo or fetus before viability (a.k.a. miscarriage).

2. The deliberate expulsion of a live embryo or fetus before viability.

3. The deliberate killing of an embryo or fetus while it is in the womb.

Traditionally, the word "abortion" included 1 and 2, but not 3. The term "deliberate abortion" referred to 2 and nothing else. Indeed, this terminology persisted in canon law until May 23, 1988, when the Code Commission published an authoritative interpretation of canon 1398 (which imposes latae sententiae excommunication on "a person who procures a completed abortion") stating that abortion, in this context, includes not only induced expulsion of the fetus, but also the deliberate killing of the fetus while still within the womb.

However, common language had already been using the term "abortion" to include 2 and 3 for many years; the 1917 Catholic Encyclopedia uses it in this wider sense.

So it can be difficult to determine exactly what "abortion" means in a very old quotation.

With this caveat, I will point out that there is indeed a significant tradition behind calling abortion "murder":

* St. Hippolytus of Rome (d. 235) wrote that the heretic Callistus told Christian women that they were permitted to live with lower-class (slave) men without marriage, and to avoid scandal they could "take drugs to render themselves sterile, and to bind themselves tightly so as to expel what was being conceived". Hippolytus wrote that in this way Callistus was "teaching adultery and murder at the same time."

* St. Basil the Great, in his Letter to Amphilochus (374 AD): "A woman who has deliberately destroyed a fetus must pay the penalty for murder" (188:2). And "Those also who give drugs causing abortions are murderers themselves, as well as those who receive the poison which kills the fetus." (180:8)

* Among the "laxist" propositions condemned by the Holy Office in 1679 was the following: "It seems probable that every fetus still in the womb does not have a rational soul and begins to possess it only at birth, with the result that 'homicide' is not committed in any abortion." [... in nullo abortu homicidium committi].

Anyway, that's all I know.... not much of an expert in this.

Anonymous said...

One more quote from St. Basil's letter. This has nothing to do w/ abortion, but I found it in my three-volume Faith of the Early Fathers while looking for the other quotes:

"A man who, in a fit of temper, used an axe on his wife is a murderer." (188:8)

I once heard that this isn't the law in Texas! Maybe they could learn from the early Church Fathers....

Anonymous said...

In response to Br. Robert, Thomas sees the progression as three distinct souls: one is corrupted before the other can take its place. The argument against genetic code being sufficient for "matter proportioned to the form" that I found most convincing was the problem of twinning: the matter is not proportionate to the form when there is still a possibility of having two or more individuals come out of that matter.

In response to Larry, you're partly right. There was a distinction made in the Church between early and late abortions and the idea was that an early abortion was still a sin, but not the equivalent to murder (see Jean Porter, "Is the Embryo a Person?" in Commonweal). But this follows the idea of delayed hominization: if the embryo does not have a rational soul yet then it cannot be a human person and the termination of its life could not be murder; if later the embryo developed enough to receive the rational soul, then the termination of its life would be considered murder. As for theologians throughout history, the following groups/theologians all support delayed hominization: Augustine, Jerome, Anselm, Peter Lombard, Hugh of St. Victor, Aquinas, Council of Trent, Pope Gregory XIV, and is reflected in the teachings on the baptism of an aborted fetus at least as late as 1713.

Anonymous said...

Oh, and I don't know about Texas. You'll have to ask Colleen.