Human life begins at conception

I saw somebody’s new Facebook page the other day, with a picture of a small child touching a pregnant woman’s belly. The text overlaid on the image said, “Science proves that human life begins at conception.” Hey, if you keep repeating something often enough, it eventually becomes “true,” right? And you probably know a bunch of good answers to this one, like I do. But I think I’m going to try something different this time. I’m going to agree that, yes, human life does begin at conception.

In a way, it’s true. When the two gametes fuse, that’s the beginning of an important phase in the human life cycle. Of course, it’s not a “beginning of human life” in the sense that something not alive magically becomes alive, or something non-human magically becomes human. Rather, it’s a step in the construction process that will ultimately produce a new person. Two living, human gametes combine to construct the physical basis upon which all future processes will operate.

Obviously, this isn’t the only beginning in the human life cycle. The process of meiosis is also the beginning of human life—it’s the beginning of the existence of the gametes which went into that conception. So meiosis is also the beginning of human life, as is sexual intercourse, which brings the gametes together. Granted, there are any number of points along the process from meiosis to birth where the reproductive chain of events can be interrupted, leaving “the beginning of human life” without an actual human at the end. But these are all still beginnings nevertheless, and every new person did have these beginnings, even prior to conception.

There are many beginnings after conception as well. For example, the very earliest growth of the embryo happens inside a glycoprotein shell called the zona pellucida which limits the size of the embryo such that each cell division has to produce smaller cells so they can all fit. When that shell breaks, that’s another beginning of human life. Still another is implantation, when the embryo establishes the symbiotic relationship that will allow it to continue to grow and without which it will never reach maturity.

The beginning of differentiation transforms the embryo from a mere mass of cells into something beginning to resemble the human body. This, too, is the beginning of human life, since without this differentiation, the embryo isn’t going to develop into anything we would call a person. Many of the spontaneous, natural abortions that happen during pregnancy happen at this point, since the differentiation process tends to expose any significant abnormalities in the developing embryo.

And the beginnings continue. The development of a heart muscle could be called the beginning of human life, although some might prefer to wait until the very first actual heartbeats, since a beating heart is the traditional sign of life. Another beginning is the development of the central nervous system, which happens fairly late in the gestational process. It won’t be a fully-operational system in the womb, due to low blood oxygen levels, but the basic infrastructure gets built, and it’s an essential prerequisite for the things that make us persons, so the beginning of this system can accurately called the beginning of human life.

That leaves birth itself. It’s tempting to call birth “the beginning of human life,” but it might be more accurate to call it the end of the beginning. At birth, a human life has been produced, and the process of beginnings has had a successful completion. There will be more beginnings after birth, but they won’t be the beginning of the person themselves, only beginning of parts of the person’s life. Birth is where the beginnings of human life arrive at their destination, and deliver the end result.

So yes, conception and other key events in pre-natal development are all the beginnings of human life. But the beginning of a journey is not the journey. Science proves that conception, like every other identifiable stage in the human life-cycle, is part of a process of reproduction that takes things that aren’t quite there yet, and brings them closer to the end result. At each step, something that is already living and already human—the human sperm, the human egg, the human zygote, the human embryo, the human fetus—is modified in some way that brings it closer to becoming a real person. Conception is just one of those steps, not the end result.

And here’s the other point that science would like to remind us of: this process is taking place inside the body of a person. If we’re going to appeal to science, then we need to listen to everything that science has to tell us about the process. This is not a process that’s happening in isolation, independently. It’s happening inside the body of a person. And that person has the right to decide whether or not to use her body as a host for such a process. No one has the right to force her to use her body against her will, not even for the sake of sincerely held religious misconceptions about the biological significance of conception.

So if you’re clicking the Like button on that Facebook page, good on you for turning to science for questions the Bible can’t answer. But please, if you’re going to use science, use it right, and don’t just pay it lip service in order to promote the abuse and enslavement of women. Thanks.


  1. themadtapper says

    When you argue with them about the specifics on when those cells become full-fledged humans, you are (whether you mean to or not) conceding that an embryo/fetus’s rights trump the woman’s, and are simply haggling over where the line is drawn for when it happens. The whole “life begins at conception” thing is really just a red herring. It bogs you down in discussions about when life begins and what it means to be a human being and distracts from the real heart of the matter: the right to bodily autonomy.

    Even if you concede that an embryo or zygote has the same rights as a fully grown person, you still have two humans occupying the space and resources and each having a right to their own bodily autonomy. When a pro-lifer wants to argue about when life begins, they’ve already assumed that the proto-human’s rights trump all else. Bodily autonomy is the real issue that needs to be settled. It’s also an issue the pro-lifers have no good answers for, which is why they avoid it like the plague and try to shift the conversation to the topic of personhood.

    Maybe the woman doesn’t want to share that space and resources, or give up her own health and safety. Should she be forced to? Should the government have the power to compel people to sacrifice bodily autonomy for the life of someone else? Would you want the government coming in and compelling you to give up a kidney or even something more vital so someone else can live? The pro-life answer is always, without fail, going to be that the woman waived her rights as soon as she engaged in filthy sex like the dirty sinful slut she is. See, she chose to risk pregnancy, so she doesn’t get to complain about her rights anymore.

    The obvious reply to that is, “What about those who did not chose? In other words, rape victims.” This promptly sends a pro-lifer into incoherent rage because it yanks the rug out from under them and forces them back into discussing bodily autonomy. They don’t want to do that. So they rage about pro-choicers “distracting” or “emotionally manipulating” by bringing up the topic of rape. Ultimately, crying foul on the topic of rape and shifting the discussion to personhood are both attempts to avoid the topic of bodily autonomy, which is the truly pertinent matter when discussing abortion rights. Don’t play the game with them. Even if you think you have science on your side, you lose by even engaging them on that battlefield because they’ve defined the battlefield in a way that already gives them the advantage.

  2. governmentman says

    themadtapper, I feel like you’re using rhetoric to obscure another important point about the limits of the bodily autonomy argument. See Judith Jarvis Thompson’s “A Defense of Abortion” for more detailed examples.

    Basically, the only separation between an infant and a term fetus is its location inside or outside a woman. If we have moral obligations to infants, we should have all the same obligations to term fetuses, decreasing as the relevant fetuses regress closer to embryohood, blastocysthood, and so on.

    Those rights conflict with the rights of the woman inside whom the fetus resides, but most people have the intuition that a fetus in the process of being born has most of the same moral rights as a newborn infant, and if it is just as safe and easy and convenient to deliver it, then it should be delivered. The question is, why should any particular fetus be killed rather than delivered and cared for? The easy answer right now is that we lack the technology to care for insufficiently developed prenatal humans. But in principle if we could incubate blastocysts into humans, should we do that rather than discarding them from a woman who doesn’t want to care for them? If not, then why not?
    If the move is to deny personhood and its concordant rights to fetuses, then why should we not similarly deny them to infants?

    • Deacon Duncan says

      Basically, the only separation between an infant and a term fetus is its location inside or outside a woman.

      That’s not strictly accurate. Birth changes a lot more than just the location of the organism, including the fact that, following birth, the baby begins breathing for the first time. That’s significant, because breathing raises the oxygenation level of the blood high enough to support consciousness, one of the defining attributes of personhood. But more than that, birth also marks the point where it is possible to address the rights of the baby independently of the rights of the mother, such that if the mother does not want the baby, someone else can take it away and care for it without violating the bodily autonomy of the woman. It might be arguable whether or not an infant is fully deserving of full rights as a person the moment it is born, however it does no harm to err on the side of caution in this case. If it were to turn out that we protected an undeveloped organism that did not deserve full protection, at no harm to anyone else, then no real damage has been done. The biological continuity between the fetus and the neonate is no argument for denying protection to the latter, since the morality of such issues is based on more than just narrow, anatomical analysis.

  3. krambc says

    The ‘moment of conception’ is a theological argument about ensoulment; specifically developed in the Catholic dogma for the Immaculate Conception – free of original sin – of Mary as a suitable hostess for the fruit of her womb, Jesus.

    When talking with Anglophone protestants, I prefer to use the biblical argument; life begins at first breath.

    Genesis ch2 v7: “Yahweh God shaped man from the soil of the ground and blew the breath of life into his nostrils, and man became a living being.”

    Job ch33 v4: “God’s was the spirit that made me, Shaddai’s the breath that gave me life.”

    Ezekiel ch37 vs5,6: “The Lord Yahweh says this to these bones: I am now going to make breath enter you, and you will live. I shall put sinews on you, I shall make flesh grow on you, I shall cover you with skin and give you breath, and you will live; and you will know that I am Yahweh.”

    Better yet, just ask why god – who ensouls all humans at conception – promptly calls so many blastocysts home to heaven; easily one-third to one-half of all human conceptions end in spontaneous abortion in the first trimester.

    That makes god the biggest abortion provider ever.

    • Deacon Duncan says

      Indeed. The story of Noah tells us that at one point, God terminated every single pregnancy on earth, along with all the other innocent lives. I like to point out the fact that God is so pro-choice, he refused to interfere with Eve’s right to make a choice that he knew would result, not just in the mortal deaths of all of her offspring and descendants, but that would send most of them to eternal damnation in hell. That’s way more pro-choice than any of us.

  4. brucegee1962 says

    If you really want a “scientific” definition for when a fetus becomes a human, the only one that would make sense is if we were to use the same definition for the beginning of life that we do for its ending: when brain activity becomes detectable. I don’t think anything can be called human if it can’t think.

    However, the “bodily autonomy” argument mentioned above trumps the “definition of human” argument. Even if a fetus could be considered a human being, it still doesn’t automatically get to trump another person’s right to bodily autonomy.

  5. grumpyoldfart says

    “Science proves that human life begins at conception.” Hey, if you keep repeating something often enough, it eventually becomes “true,” right?

    I saw a newspaper cartoon years ago where the Christian lecturer was trying to emotionally blackmail his audience. He drew a single dot on the chalkboard and said, “Here is the zygote at the moment of conception. Let’s call him Timmy…”

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