Foetal Personhood

This essay discusses when you can abort (kill[A]) a foetus, and the connection or otherwise with whether it is a person.

The criteria defined in UK law for deciding whether a foetus is killable or not are somewhat complex. So, in order to clarify my understanding of the legal position, and perhaps to help anyone who is unsure whether they can legally kill a particular foetus they are physically, parentally or medically connected with, I have drawn up this handy flowchart[B]:

  • [1] This wording is my attempt to summarise the criteria by which the limit on abortions was reduced from 28 to 24 weeks in 1990, and by which further reductions have recently been called for.
  • [2] The outcome of Joanna Jepson's court case was that the Crown Prosecution Service decided not to prosecute two doctors who aborted a foetus with a cleft lip and palate at 28 weeks because they were "acting in good faith".


So what does it mean to be a person? I suggest that personhood has two relevant and important characteristics[C]:

  • Intrinsic. Personhood is defined by what the entity in question is, and not by the state or actions of some third party. That is, one should be able to determine an entity's personhood by examining it in isolation. If a person is a person only because the government says so, you end up with the situation which led to the Holocaust - the Nazis defined Jews, homosexuals and gypsies as non-people and set about eliminating them.
  • Irrevocable. Once someone is given personhood, they keep that status until they die. Nothing can change in the future to make that person no longer a person. If personhood were revocable, perhaps by government fiat or by mental disease, we would all need to be watching our backs, particularly in old age.

Persons are afforded special protection in law which is not extended to other entities such as animals, plants or rocks. For example, when is it legal to kill a person? UK law admits three reasons:

  • as punishment (this right is reserved to the state)
  • in self-defence
  • in defence of others (including as part of a declared war)

In any other situation, you would be punished. Therefore, to say that you can kill something with impunity in circumstances other than those above is to say that it isn't a person.

Abortion law reflects this in that you can kill a foetus at any time for self-defence (i.e. if the life of the mother is in danger), and you can't kill a newly-born baby. However, as we have seen, abortions are also permitted, in some cases up until birth, for a wide variety of other reasons unrelated to the three given above.

So what is the law saying about the question of whether a foetus is a person? Logically, there are three possibilities - always, never and sometimes[D]:

Always A Person

If the foetus is always a person, then we would either need to repeal all the existing abortion control laws and ban abortion except in self-defence, or we must add some more legal justifications for killing to the list above, including having a disability and causing some other person mental or physical distress. To be consistent, we would then need to permit killing other types of people, such as adults, for the same reasons.

As either option is seriously inconsistent with the existing body of legislation, this cannot be the position of UK law on the question.

Never A Person

The second possibility is that the foetus is never a person until it fully emerges from the birth canal. That is to say, personhood is defined by the foetus/baby's location in three-dimensional space. This would make it reasonable to kill it at any time while it was still inside the womb, but it would also mean having a definition of personhood which was not intrinsic. After all, if geographical location may determine personhood, it would be reasonable and consistent if we were to choose to define those inside prison cells in Guantanamo Bay, for example, as not people.

However, it's clear that this is also not the stance of UK law. If it were, abortion laws would not exist, as they would merely be arbitrary restrictions on the entirely reasonable actions of women.

Sometimes A Person

The last possibility is that a foetus is a person some of the time. Given our elimination of the two possibilities above, this remaining logical option must be the position of UK law. This would mean that abortion law is an attempt to define under what circumstances a foetus is a person, thereby preventing it being killed when it is, and allowing it when it isn't. Personhood and killability are legally linked.

But we see that in the chart given above, and therefore in the law it represents, personhood is revocable. That is, it's possible for a particular foetus to be classed as killable, then as not killable, then later as killable again. This could happen if, for example, a follow-up scan is performed at 26 weeks and a previously-unknown disability is discovered.

Additionally, if the law is defining personhood in order to define killability, then it is using many extrinsic criteria. According to the flowchart, the following factors can all affect the position in certain circumstances:

  • The mental health of a mother's already existing children
  • The current state of medical science (which defines the age below which abortion is permitted)
  • The "good faith" of any doctors involved

None of these criteria are intrinsic to the foetus. So a declaration of personhood for one entity can depend on the mental state of one or more other people; and a 23-week-old foetus was not a person in 1989, but an identical foetus today is.


When it comes to people, the law says that you can't kill them except for the reasons listed above. So in the case of foetuses, what is the law saying? Either they are people, and it's allowing the killing of people on grounds like having a cleft palate or disturbing another's mental health, or else it's using one of several very strange definitions of "person". For example, in the "Sometimes A Person" scenario (which seems to be the stance of UK law) the foetus's personhood is neither irrevocable nor intrinsic.

I think that all participants in the abortion debate need to be able to have a defendable answer for the questions: "What makes something a person? Applying that, when (if ever) is a foetus a person?"

[A]: I use the word "kill" throughout this essay because I think it's a reasonable and common word to use for the process of changing something alive to being not alive by deliberate action. I have attempted, as far as is possible, to use non-loaded language - for example, the medical term "foetus" instead of the loaded "unborn child". (Back)

[B]: It's quite possible that I've misunderstood the law, or have not reflected the full complexity of it in this flowchart. My main source was the website of "Abortion Rights", a pro-abortion organisation. If so, I apologise - I've only just started studying the situation. Corrections and improvements are welcome; please email me. (Back)

[C]: I freely admit I am asserting rather than "proving" this. I do so on the basis of the unacceptability of the alternatives, as outlined in the text. However, I would happily hear arguments against these assertions about the nature of personhood. (Back)

[D]: To be complete: it is also possible that the law does not say anything about whether the foetus is a person. Because personhood is positively defined, that reduces to the second option, "Never A Person". It is also possible that the foetus is sometimes a person, and the law does define when it is, but this definition is neither contained in nor reflected by abortion law. Given that abortion law is the primary situation in which this question needs to be answered, this position seems absurd, and so is not considered further. (Back)

Original URL: