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Our Identity Remains the Same Throughout Our Entire Life

I have been heavily involved in the pro-life movement for about five years now. I have done outreach with a number of pro-life groups, and as I have engaged people in conversation I find there are two things many people have in common.

The first is that many people have difficulty in thinking abstractly. This makes it much easier to justify killing the unborn while decrying a tragedy like the Holocaust. In the Holocaust, the victims were out in the open, undeniable. In abortion, the victims are hidden inside the mother’s womb; the killing is done in private abortion clinics, away from the public eye. Many of the people I talk to haven’t done much philosophical reflection about the moral status of the human embryo/fetus nor about the moral permissibility of abortion. Often the more ridiculous arguments are knee-jerk reactions, and the person I am talking to can be willing to abandon that line of reasoning once I ask enough probing questions.

The second thing I have noticed is found among people who consider themselves “personally pro-life” but don’t want to “force their views” on someone else. While they may say that they believe the unborn organism is a human being, they don’t really believe it. If they did, rather than saying “I would never kill my child, but I can’t tell someone else not to do it,” they would find abortion just as appalling as those of us involved in trying to end it. They would take steps to protect those innocent children who are being legally and mercilessly slaughtered in abortion clinics, just as Oskar Schindler and Corrie ten Boom acted to protect Jews during the Holocaust. They would agree with us that the practice of abortion needs to come to an end, regardless of the fact that we have to tell people they are wrong.

The purpose of this essay is to explain why the unborn should be seen as full human beings from fertilization. On top of that, I plan to explain not just why they are human beings, but why you were you at that early stage in your development. That wasn’t some abstract thing we called a human organism growing and developing inside your mother’s uterus. That was literally you, just as much as you are you now, the person reading this essay.

It is outside the scope of this essay to cover the scientific arguments that we are biologically human from fertilization. Instead, this essay will focus on the philosophical side of the issue: the fact that we are identical to ourselves through all stages of our development.

Personal Identity with the Embryo

As we know from the science of embryology, the unborn, from fertilization, are biological members of the human species. Pro-choice people assert that there’s no clear line to be drawn between non-personhood and personhood, but they’re wrong. The clear line is at fertilization, before which you had two non-human entities, the spermatozoon and the ovum, and after which you have a new human individual. This implication is unacceptable to the pro-choice advocate. However, it makes perfect sense to draw the line there and it doesn’t make any sense to draw the line anywhere else. From the point of fertilization, the mother’s and father’s DNA have combined to form the unique DNA of a new human individual, and everything that individual will develop and become is written in their genetic code. I have brown hair and blue eyes now because that zygote had the genes for brown hair and blue eyes. The gene for gender is even present, so although I did not yet have visible sex organs I was already a male at that point. It makes perfect sense to say I was that zygote in my mother’s womb. It doesn’t make any sense (and it is not true) to say I merely came from that zygote.

Pro-choice people tend to view the unborn human organism as a shell in which the human person comes into existence sometime later, inhabiting the human organism. Commonly the pro-choice advocate will point to your brain as what grounds your personal identity. But this has at least two major problems.

If your identity (or personhood) is seen as simply being a collection of memories, thoughts, emotions, and so on (in other words, the collection of your mental states), then you are literally a new person from one moment to the next. If I am just the collection of my mental states, then I cannot be the same person now as I will be tomorrow when I have collected new memories. Besides, there must be something doing the experiencing; otherwise, what, exactly, is it that is collecting those memories and experiences? This is putting the cart before the horse. Apart from being counterintuitive—after all, I have memories of my childhood, and I can honestly say that it was my childhood, not the childhood of a previous occupant of the physical organism I now inhabit—it would make our criminal justice system inherently unjust. It would be unjust to put me in prison for a crime I did not commit, and if I am literally a different person now than before I committed the crime, I could not justly be punished for it.

Another problem with this idea is that it establishes a counterintuitive form of dualism. Edwin C. Hui, in his book At the Beginning of Life: Dilemmas in Theological Bioethics, argues that this dualism results in the view that the physical organism can exist independently of the psychological entity, and it’s the psychological entity that should be given ontological significance. In other words, this view holds that the psychological entity is the one with intrinsic value—the one whose existence is important—not the physical organism. This view contradicts normal human experience, however.

The sensations that our body experiences need the body to be a subject of experiences, to experience these sensations, and the psychological component is necessary to comprehend the sensations so they can be understood as meaningful. Since the body and psychological components are both necessary for our experiences, then both are necessary for the “I,” the person who is the subject of experiences. Since the body is a necessary component to the person, one cannot hold that the body comes to be at one time while the person comes to be at another time.

Alexander Pruss, in his essay “I Was Once a Fetus: An Identity-Based Argument against Abortion,” takes this argument further. I am either identical to the embryo that was in my mother’s womb or I am not. If I am not, then what happened to the biological organism I “came from”? There are only two possibilities: either the embryo I “came from” is alive or it is dead.

If the embryo is dead, then what happened to it? When did it cease to exist? If it was literally a part of the woman’s body, then it could have ceased to exist when it was removed from the mother’s body. But this is highly implausible. The embryo has a different genetic code than any part of the mother’s body. Additionally, the fetus is not controlled by the woman via the umbilical cord. The fetus takes in nutrients from the umbilical cord, but the cord, itself, does not direct the embryo’s development. The embryo directs her own development from within herself. The embryo does not work toward the good of the mother’s body in the way that the rest of her body does: that is, as a unified whole with each part fulfilling a certain function to keep the woman’s body functioning properly. The fetus remains a wholly separate entity from the mother. In no way can the embryo be said to be a part of its mother’s body.

Another possibility is that the embryo could have died when the person came to inhabit the body—that is, when the body gained consciousness and self-awareness—but this also seems false. The embryo from the very beginning is a self-directed organism, developing itself from within. This means that the embryo would have ceased to exist when it gained the ability to be conscious or self-aware, but this is absurd because entities don’t die when they gain an ability the development of which is rooted in the entity’s developmental program or plan. So the embryo can’t be dead.

If the embryo can’t be dead, that means it is still alive. After all, every biological part of the embryo developed into me. Since the embryo developed into me, it has become all of my body. I can’t separate out one part and say “that is the embryo.” So while the embryo exists, I also exist. This means that I cannot be an organism because there cannot be two organisms that have the same body. So if I am an organism, I am the embryo. But if I am not the embryo, then I am not an organism. This would also mean that I am not a rational animal, and this is an absurd consequence because human beings are rational animals. If we are rational animals, then we are organisms.

There are other problems with the view that the embryo is alive but I am not the embryo. This would mean that persons do not have sexual intercourse, their bodies do. It would also mean that rape is merely a property crime, not a crime against a person. Additionally, it would entail that two numerically different entities occupy the same place at the same time, which violates a plausible law of physics.

So it seems pretty clear that not only is the embryo that was in my mother’s womb still alive, but that I am identical to the embryo that was in my mother’s womb. If the embryo is still alive but I am not identical to it, this leads to many absurdities.

I do not look much like the zygote that I once was, but then again I don’t look much like the toddler that I once was, either. Nevertheless, the zygote does look like every human being does at that stage in their development. Further, if merely looking human is what makes us human, then someone like Joseph Merrick, commonly known as the Elephant Man, wouldn’t have been human.

I also function in a substantially different way than the toddler I once was, as well as the zygote I once was. This is because human beings are substances, which are entities that maintain their identities through change. When I was a toddler, I was much smaller. I could not engage in rational thought, nor had I yet gone through puberty. I also do not remember what it was like to be a toddler. But I remained the same “me” throughout all of the changes. All of these changes were changes that were in my nature, in my programming, to undergo.

Artifacts vs. Substances

The world we live in contains many different things consisting of different levels of order and degrees of unity. A heap is a collection of items with no structure to it. It only has unity insofar as it consists of items that are spatially close together. A pile of metal is an example of a heap. The metal can be made into something else with unified order, such as a car. But the pile of metal, itself, is merely a heap because none of the parts are unified. This is why the argument that the unborn is just a “clump of cells” is completely misguided. A clump of cells (such as a group of skin cells) is merely a heap, a weak unity with no order. But since the unborn entity from fertilization has numerous cells that divide, working in tandem to become more biologically complex, all of the cells are working together in a unified whole toward the good of the organism.

Then there are artifacts and substances. William Lane Craig and J.P. Moreland, in their book Philosophical Foundations for a Christian Worldview, list several differences between artifacts and substances.

Artifacts represent the next level of unity. Whereas a heap only has a weak kind of unity, artifacts have a stronger kind of unity because all of their parts are unified toward a particular function. An artifact finds its identity in its parts, and it is an object that becomes different if you swap out its parts. An artifact doesn’t really exist until it is completed (a clock without its hands is not really a clock at all, but a human being who loses his hands in an accident doesn’t cease to be a human). Since an artifact is constructed with a purpose extrinsic to itself, its parts bear no intrinsic direction to the good of the whole.

A substance is the highest type of unity there is. Substances are entities that maintain their identities through change. All living things are substances. A substance exists ontologically prior to its parts, which is just a fancy way of saying that a substance exists before its parts develop. A substance is not artificially constructed, like an artifact, but is conceived and develops naturally. Substances, unlike artifacts, have an internal unity where all of their parts are intrinsically directed to the good of the whole.

To illustrate this concept, think of a car. If you have a classic automobile, say a Mustang, and it is exactly the same as you bought it, except that you had replaced the seats, you have a different car than the one you bought and it will lose value. A collector of classic cars won’t pay as much for it, if they buy it at all, because it’s not the same car that you originally bought.

We can take it a step further. Suppose I have a classic Mustang in my yard that I’ve really taken care of over the years. My neighbor has a Mustang, too, but his is beat up and generally in poor condition. He wants my Mustang, but instead of just stealing it outright, he dismantles it piece by piece and replaces it with the parts from his car. A few weeks down the road I now have a beat up Mustang in my yard, and he has a nice, “like new” Mustang in his yard. I walk across the street to ask what the meaning of this is and he argues that the car in my yard is, in fact, my car. But this cannot be. The one in my yard can’t be the original. My car is the nice one that is in my neighbor’s yard.

This is where many people tend to misunderstand human development. Richard Stith is a philosopher who argued that pro-choice people tend to view human development like construction of a car. A car’s purpose is to be able to drive and carry passengers around. If a car doesn’t drive, then it’s really only a car in name only. And certainly no one would say I have a car when you put the first two pieces of metal together.

Human development is very different from constructing a car. Rather, human development is like a Polaroid picture. You take the picture and it begins as a brownish-grey smudge, but it will soon develop into the picture. The picture was there the whole time, you just couldn’t see it because it was not given time to develop. Whereas the metal will not develop itself into the car but requires an outside builder to do it, the unborn child from fertilization develops herself from within into a more mature version of herself.

This is why the objection that the unborn are only “potential persons” is also misguided. This confuses two different types of potentiality: passive potentiality and active potentiality.

Passive potentiality is the potential something has to become something else, such as a heap of metal having the potential to become a car. Things with this kind of potentiality don’t have it within themselves to become another thing, and they lose their identity when they do. The heap of metal becomes the car when it is constructed; it is no longer a heap of metal. It doesn’t become a car until an outside builder makes it a car.

Active potentiality is the potential something has within itself, and as this potential comes from within itself, this change is identity-preserving. The unborn, from fertilization, have the active potential for rational thought, for speech, for hearing, and so on. They just need time to develop the right hardware to be able to engage in those activities. The unborn may not currently be self-aware because they haven’t developed their brain enough to do so, but consciousness and self-awareness only have to do with our awareness of existing through time, not with our actually existing through time. So while the unborn have the active potential to develop, they are actual persons, not potential persons, because being a person is about the kind of thing you are, not the kind of thing you can presently do.

So as we see, this is why we are identical to the embryo that was in our mother’s womb. Not only were we living members of the human species as we are now, but all of the changes we underwent were within our own programming. So we retained our identity through the whole process. This not only has implications in the abortion debate but also in the embryonic stem cell research debate. Experimenting on human beings is wrong, and since the unborn, even in the first few days of life, are full-fledged human beings, ethics demands that we oppose killing embryos for their stem cells, as well as opposing the creation of embryos for no other reason than harvesting their stem cells.

If we want to be people of virtuous character, we have no choice but to stand against unethical procedures such as abortion and embryonic stem cell research. There is ample reason to believe that not only are the unborn full-fledged human beings, but they are deserving of the same respect that older human beings are deserving of. If we truly believe in treating all humans equally, justice demands no less.

My thought on human personhood has been greatly influenced by a number of thinkers, such as Aristotle, Boethius, Thomas Aquinas, Frank Beckwith, J.P. Moreland, William Lane Craig, and Patrick Lee. For more on the Substance View, and why it should be viewed as the correct account of human identity, see (for example) Body and Soul: Human Nature & the Crisis in Ethics by J.P. Moreland and Scott B. Rae and Defending Life: A Moral and Legal Case against Abortion Choice by Frank Beckwith, among others.

Works Cited

1. I realize there were other people groups captured, tortured, and killed during the Holocaust. I’m using the Jews to represent all the groups of people since they were the largest.

2. This is an uncontroversial fact of science. Embryologists consistently agree that human life begins at fertilization. Pro-choice philosophers even agree with this basic fact, making a distinction between the biological human (human in the genetic sense) and the human person (human in the moral sense). Since pro-choice and pro-life embryologists agree with this basic fact of biology, I don’t see why we should dispute this point.

3. I owe J.P. Moreland for the observations in this paragraph. For more on why we are not the same thing as our brains, see J. P. Moreland, “Naturalism and the Crisis of the Soul,” Southeastern Baptist Theological Seminary, accessed July 18, 2015,

4. Edwin C. Hui, At the Beginning of Life: Dilemmas in Theological Bioethics (Downers Grove, IL: InterVarsity Press , 2002), 71-72.

5. The article is dated November 25, 2001. Alexander R. Pruss, “I Was Once a Fetus: An Identity-Based Argument against Abortion,” Alexander R. Pruss website, accessed July 18, 2015,

6. I am using the term “embryo” here to denote all stages of unborn human life. I decided to use embryo because 1) it includes the zygote (which is considered part of the embryonic stage) and 2) if I was identical with the embryo in the womb, then I was certainly identical to the fetus, which is a later stage of development.

7. The observation in this paragraph comes from Stephen Napier. The rest of this section comes from the aforementioned essay by Alexander Pruss, unless otherwise noted.

8. The observations in this paragraph also come from Stephen Napier.

9. The information in this section is drawn from William Lane Craig and J. P. Moreland, Philosophical Foundations for a Christian Worldview (Downers Grove, IL: InterVarsity Press Academic, 2003), 220-221, unless otherwise noted.

10. Ibid.

11. This is a point made in Timothy Hsiao, “A Defense of the Perverted Faculty Argument against Homosexual Sex,” The Heythrop Journal (early view): n. 5, doi: 10.1111/heyj.12134.

12. This is an example I heard on the Please Convince Me podcast by J. Warner Wallace. It’s essentially a modern update of the Ship of Theseus thought experiment postulated by ancient philosopher Plutarch.

13. See Richard Stith, “Does Making Babies Make Sense? Why So Many People Find It Difficult to See Humanity in a Developing Foetus,” Mercatornet, accessed July 18, 2015,


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