A brief case against abortion

Most of my friends are aware of my strong views on abortion, but unless they have witnessed me having a conversation about it, they are unlikely to know why I hold the views that I do. So I thought it would be worth me giving a brief outline of what’s wrong with abortion, and why arguments for the ‘pro-choice’ position fail. Much more could be said, but I have a habit of writing blogs too long for people to read, so if you are unsatisfied with anything said here, feel free to ask me about it, rather than assuming that there is nothing else I could add to my case. My first post will lay out the positive case against abortion, while my second post will respond to typical pro-choice arguments.

Against abortion

There are 3 main arguments against abortion which I find persuasive, though it would be wrong to think that they are not closely linked. The first is that the unborn are human beings, and that it is wrong to kill human beings. The second is that it is implausible to suppose that there is a moral difference between newborns and the unborn – and since it is wrong to kill newborns, it is also wrong to kill the unborn. The third is a prudential reason: if we are unsure whether something has a right to life, but we believe that there is a moderate chance that it has a right to life, then it is wrong to kill it. Since there is a moderate chance that the unborn have a right to life, then it is wrong to kill the unborn.

I should add that these arguments are all enough to convince me that even a zygote ought not be killed. So I will frame my argument that way – but they can all apply (even more strongly) to foetuses. So do not reject my arguments simply on the basis that you find the zygote being a human being very unintuitive – think also about foetuses, and whether you ought to at least oppose abortion of the unborn at a late stage.

Argument 1

The first argument is that the foetus is a human being, and that it is wrong to kill human beings.

The first premise seems correct. After all, most of us would agree that we began to exist when we were conceived by our parents, even though we have changed significantly(!) over time. This intuitive position is assumed in most embryology textbooks, which tend to say in no uncertain terms that conception is the beginning of human life. In any case, it seems very difficult to suggest that the unborn entity turns into a completely different person just from a short trip down the birth canal. Both mothers and fathers have a particular responsibility to their children, and this is because it is their union which causes a new human organism to exist. It is intuitive to think that this human organism begins to exist when the gametes from the two parents meet, and it is intuitive to think that we are the same organism as the baby our mothers gave birth to, and that we are the same organism as the baby two days before birth, and so on. If this were not the case, it would be meaningless to talk about our gestation, or our conception. If we can maintain that I am the same person as yesterday, despite the fact that my body has changed location, developed and matured, and despite the fact that I might not currently be conscious (I might be asleep, for example), then there is no reason why we should say that the newborn baby is a different person to the day before, despite changes in location, development, and conscious capacity. So it seems clear that the unborn is a human being. After all, it is the same thing as me, and I am essentially a human organism.

The second premise also seems correct. On the surface of it, it is very obviously true. There doesn’t seem to be much reason to think that murder is wrong unless we hold to a principle at least something like this principle. Of course, there is much debate about why, exactly, killing human beings is wrong. Some say it is because it deprives them of a future, others because life is sacred, others because it frustrates desires. But it seems to me that most plausible accounts of why killing is wrong apply just as much to the unborn as they do to adults. It can’t just be because killing is painful, because some killing is not. It can’t just be because killing causes relatives and friends to suffer, since it would still be wrong to kill someone even if they were hated and outcast from society – indeed, we would typically see this as even worse! It seems like there is something intrinsic to humans that makes them valuable, and gives them a right to life. But this doesn’t seem to be dependent on how loved or treasured they are by fellow humans, or how much pain they feel, or how many good things they’ve achieved or done, or whether they’re conscious (it’s wrong to kill people in comas too). If it were, then it would be more wrong to kill those who are popular, or those whose deaths are more painful, or those who have a more fulfilling conscious life (and less wrong to kill newborns, blind people, mentally disabled people, and so on). But the value of human life doesn’t come in gradations – it’s not the case that some people are more valuable than others, or that some people have more of a right to life than others. Why think that this should change when humans are the other end of the birth canal? The worth and rights of humans do not come from any of these other things, and they does not come in gradations. So all human beings have a right to life, and all humans are equally valuable. This confirms the second premise. It follows that killing the unborn is the immoral killing of a human being – an extremely serious issue.

(Side-remark: of course, some people do think that killing is permissible in certain circumstances, e.g. in war, or in capital punishment. I personally think that killing is never permissible, but even if you disagree, you could easily modify this premise to something like, “it is wrong to kill an innocent human being”. Few would argue that the unborn are not innocent, so this argument seems to work just as well.)

Argument 2

The second argument against abortion is very clearly linked to the first, and it is difficult to separate the two. This argument argues from the failure of pro-abortion advocates to advance a plausible account of when and why, between conception and infancy, the child gains human rights.

Interestingly, this point has even been conceded by some of the foremost pro-abortion ethicists, like Peter Singer and Michael Tooley. The conclusion they draw is that there is nothing intrinsically wrong with killing infants either. If, like most people, you agree that killing infants is seriously immoral, then you ought to apply the same principles to the unborn, since there is no morally significant difference between them.

There are many criteria which people put forward as the criteria by which humans gain rights. But usually these are incredibly arbitrary. Moreover, they usually exclude newborns – but since killing newborns is obviously very immoral, then this suggests that these criteria are false. There are a few criteria which do differentiate between the unborn and newborns, and these are helpfully summarised in what has become popularly known as the SLED test.

SLED stands for “Size, Level of Development, Environment, and Degree of Dependency”. These are supposed to cover the major differences between the unborn and the newborn, and they will suffice for the discussion here. It is clear that size does not determine rights – big people have no more rights than small people. Similarly, it is difficult to suggest that level of development determines rights. Adults have no more rights than newborns – they are an all or nothing affair. Environment should not determine rights: people do not have more or less rights depending on where they are – the birth canal, in particular, cannot plausibly be seen as a physical boundary to the extension of human rights. Degree of dependency also does not determine rights. We rightly care for the outcasts and dependent in our society by providing them with food, education and healthcare. The fact that they are dependent on us does not mean they have less of a right to life. If anything, they need more protection and help than the rest of us. So it seems like none of the main differences between the unborn and the infant are capable of conferring value. The most plausible conclusion to draw from this is that the unborn has all the same rights as the newborn, because of what it is: a human being, with human rights.

Argument 3

The third argument against abortion is prudential, and says that if there is a moderate chance that something is a human being with a right to life, then it is wrong to kill it.

This reason can be best explained with an analogy. Suppose you are in charge of the demolition of a building, and you have a whole team hired to help you do the job. In particular, you hire a group to make sure that no one is in the building at the time of demolition. Now, suppose you are waiting on the final checks and ready to blow the building up. You ask your health and safety officer whether there is anyone in the building, and she replies, “well, I don’t really know. I don’t think so, but I’m not really sure.” Surely it would be clearly wrong for you to proceed without exceptionally strong evidence that there was no one in the building, even if you consider it relatively unlikely that someone is in there. Similarly, in view of the above arguments, and in the absence of strong evidence that the unborn are not humans with rights, it would be clearly wrong to proceed simply on the basis of agnosticism.

There is a danger that calling this a prudential reason implies that it is not wrong, but simply unwise, to support abortion. I hope this implication is not believed: it would be an immoral kind of recklessness and disdain for human life which allowed the demolition of the building still to proceed, and the same is true of abortion. If we really care about human life, we would take the utmost care to ensure that we do not end it. To take it any less seriously is to disregard life and to act immorally.


It follows from these arguments that it is wrong to kill the unborn. Note the gravity of this: if these arguments are correct, abortion is not just trivially wrong, like a white lie. It is not the kind of thing which can easily be counterbalanced by considerations of convenience, autonomy, and so on. In the same way that killing newborns is an extremely serious matter, and that killing newborns cannot be justified by appeal to convenience, health, or women’s choice, so abortion, if my argument is correct, is an extremely serious matter, and one which cannot be justified by these appeals. If my argument is correct, abortion is the killing of a human with the same rights as any other human. And that means it cannot be dismissed as an unimportant issue. If it’s possible that 200,000 human beings with human rights are being killed annually in the UK alone, the claim deserves investigation, and we’d need a very good argument that the unborn are not human beings.

It follows that any argument for abortion based on these other considerations begs the question. It assumes that the unborn does not have this kind of value or these rights. In order for these pro-abortion arguments to work, they first need to establish that the unborn has no rights. Otherwise, convenience and choice are irrelevant – they simply cannot overcome the right to life, just as with newborn babies.

My next blog post will address pro-choice arguments.

One thought on “A brief case against abortion

  1. Hi Calum,

    I notice you’ve strayed somewhat into matters of practical ethics – in which case can I make a suggestion? One thing that really troubles me with the conservative evangelical movement is the disproportionate focus on ‘individual’ morality (i.e. choices we make about highly personal matters), with very little commentary on our corporate obligations (e.g. about social structures – our joint responsibility for things like climate change, warfare, or even local social action). For example, if we Christians ought to oppose abortion, there are surely parts of ways of organising society that ought to be avoided.

    I’d be really interested to hear your thoughts on how you think Christians ought to navigate some of the ethical problems thrown up in these situations in order to redress the balance!

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