What arguments would support a secular pro-life position?



I've been thinking about the pro-life position (by "pro-life" I mean the position that abortion should be illegal. I.e. on par with murder) for awhile, and it is normally presented as a religious position, one that a secular person cannot accept.

However, I have found a number of secular pro-life proponents, including Christopher Hitchens.

So, I've been trying to understand what sort of logic would underlie a secular pro-life position. This is a sketch of my best understanding of a secular pro-life argument:

  1. Human existence is inherently good.
  2. A human exists at the point of conception, i.e. that is when her DNA first began to exist.
  3. Therefore, abortion always destroys a human existence, and is always wrong.

Granting assumptions #1 and #2, is this argument deductively valid? And, is there any logical contradiction in a secular person accepting both #1 and #2 simultaneously? #2, at least, seems to follow from what we know about genetics. #1 may be more controversial, but doesn't seem contrary to secularism. Indeed, #1 is a straightforward way to justify human rights.

Hitchens references:
- This article has a couple good youtube links.
- Also this article in vanity fair has relevant quotes.


Posted 2014-05-01T23:29:54.233

Reputation: 1 231

Your premises are way too vague. Why cant you be more specific from the start? Religion has nothing to do with deductive arguments. Human beings are more than just DNA. Human existence is so vague I have no idea what that even means. The term human being is quite different from zygote and fetus. Are you expressing that a zygote and you or me have much in common? Please list. Are you suggesting a fetus is the same as a human being and not distinct? I dont see your justification for that as written. – Logikal – 2019-01-29T21:52:14.837

Statement #2 is immediately problematic. If you accept that a human being begins with conception, in practicality you wouldn't consider all humans equal, or even close to equal. Would you sacrifice 1000 human zygotes (human beings, according to statement #2) to save one 5 year old child? I think most people would. – obelia – 2014-05-02T04:33:20.050

2That is an excellent point. I'd agree many people would choose that way, but it isn't clear this is due to inherent inequality, or if it is even a proper choice. Additionally, it doesn't seem incorrect to say that all things being equal 1000 zygotes should be preserved and raised even at significant impact to the child's quality of life. – yters – 2014-05-02T04:40:43.027

4@obelia I think that intuition is far from universally shared. It's part of what's at stake here. And it seems to be a troubling balancing method. Should we sacrifice 1000 mentally slow 5-year olds for a 15-year old child genius? – virmaior – 2014-05-02T04:46:05.787

1@virmaior I would answer unhesitatingly "no" to your question. And I do think the preference for a single fully formed person over 1000 cells is near universal when confronted with the realities of the situation and not in the abstract, when you see with your own senses the difference between a fully formed person and a microscopic group of cells that don't look or behave at all like people. – obelia – 2014-05-02T05:44:06.643

What if you were confronted with 1000 minds on a hard disk vs a 5 year old? – yters – 2014-05-02T05:47:57.483

1@obelia, Building on your reponse, the question is what principle informs the intuition you claim we would all share in the moment. And why you imagine there's a difference. Or to word it another way why do you call a 5 year old a fully formed person? Aren't they still in the process of formation? If not, what makes them a person? – virmaior – 2014-05-02T09:57:29.577

2statement #2 can be weakened to "human life may exist from the point of conception" for the position to be reasonable. There is no clear objective point where there is a transition from non-human being to human being, and it is not unreasonable to err on the side of caution. The utilitarian approach leads to other problems such as "how many pensioners would you sacrifice to save one child"? I would also argue that the value of an unborn child does not depend on whether its parents want it. – Dikran Marsupial – 2014-05-02T12:47:11.457

@virmaior - there is no principle, just the animal emotions of having to choose between a breathing, talking 5 year old child and a microscopic group of cells. – obelia – 2014-05-02T16:51:47.777

@yters - "1000 minds on a hard drive" - good question. If I had known one or more of those HD minds I might choose the hard drive. But we need to grow into that question, it's too abstract in today's context. – obelia – 2014-05-02T16:54:16.610

2@obelia Exactly, so your response shows that the instinctual choice does not provide sufficient grounds for a moral norm. Now, you might think there are no moral norms, but that's a different discussion. This discussion takes place within the assumption that there is such a thing as a principled secular moral argument. – yters – 2014-05-02T17:05:14.880

@yters - but if your moral argument is massively overwhelmed by instinct, how useful is that? Isn't it a red flag? I don't know if I'm making the case that there is no moral argument, just that "human zygote = person" is problematic. – obelia – 2014-05-02T18:24:10.103

1@obelia - Not if the instincts are inconsistent, as shown by your differing response to the 1000 zygotes vs 1000 minds. 1000 zygotes is equivalent to 1000 minds on a harddisk. – yters – 2014-05-02T18:41:39.177

@yters - I don't know how you get to 1000 zygotes = 1000 minds on hard disk. An extremely significant difference between human zygotes compared to more developed human organisms is that they don't have minds. Raising zygotes to the level of creatures capable of pain and suffering discounts pain and suffering (etc.) in any moral framework founded on that equivalence. Is that a useful direction? I think not. – obelia – 2014-05-02T20:01:18.513

1000 minds on a hard disk can be turned off and on. This is no different than zygotes developing into fully functional minds. – yters – 2014-05-02T20:26:34.653

You may need to clarify 'pro-life'. It's a political term. In that context, it typically means "make abortion illegal". Few secularists are for that, though many (majority?) are all for figuring out how to reduce them. The secularist argument (IMHO) tends to be more pragmatic: solve the problems that lead to abortion first. (Also keep in mind that the political 'pro-life' platforms also tend to have contradictory logic elsewhere...such as being pro-military and pro-death penalty...which makes the idea of tying it to 'all of human existence' somewhat problematic) – DA. – 2014-05-02T22:22:32.907

I don't grant premise #1, and i'm not sure how anyone else does either. So whether the logic is valid, doesn't make much difference. – cHao – 2014-05-03T05:32:11.910

Your three part answer is insufficient to prove the argument, because it fails to address the issue that without the mother, the zygote, embryo, or fetus would die. Just as refusing to provide a blood transfusion is not murder, refusing to allow a fetus to remain in one's uterus is not murder. At best you can argue that it's breach of contract if you argue that by having sex, the mother agrees to a contract to allow any fetus to use her body for 9 months. – Warren Dew – 2014-05-03T05:34:11.980

The missing premise, clarified in the below answer, is that it is always wrong to destroy something intrinsically valuable. If the fetus is intrinsically valuable, then abortion is always wrong. – yters – 2014-05-04T18:05:18.593

@obelia: Isn't this a bit of a straw-man; has there ever been such a situation where this decision had to be made? – Mozibur Ullah – 2014-05-07T12:20:15.120

@MoziburUllah - it's hypothetical, wouldn't call it a straw man. In the U.S. there have been proposals to legally define personhood at conception. – obelia – 2014-05-07T22:14:40.677

Hitchens isn't pro-life. Hitchens thinks that abortion counts as killing an innocent human being, but he doesn't think that killing an innocent human being should legally prohibited in this instance. – None – 2014-09-17T12:09:21.383

Hitchens accepts the same principle that pro-life is founded on, and the pro-abortion deny - that the unborn have a right to life. – yters – 2014-09-17T13:06:55.657



To make the argument valid, you'd need to say something like:

  1. Human life is intrinsically valuable.
  2. A human life begins at conception.
  3. To destroy anything intrinsically valuable is always wrong.

Since abortion is the destruction of something that counts as "a human life" by (2), then by 1 and 3 it will follow that it is wrong.

Secular arguments against abortion have been around since literally the beginning of the debate. Even religious people make a "secular" argument in the sense that the premises of the arguments don't presuppose the existence of God.


Posted 2014-05-01T23:29:54.233


This answer is inherently wrong, it is an answer by a religious pro-life user to a question made by a religious pro-life user about a matter they don't know about and they are actually aborted from it: secular relations, There is no mention to the mother life, which is not a supposed being, but an uncontroversial being. "To make the argument valid" Haha. "The zygote is a person", who are these people... – John Am – 2017-07-19T18:29:07.650

@John Am This comment makes no sense. Which of these premises is a religious belief? How would the mother's right to life make 1 or 2 false? What you're doing is just the ad hominem fallacy, which you wouldn't tolerate someone to say the same about your own position. If you want to join the conversation, you'll have to bring better game than this. – None – 2017-07-19T18:48:46.127

@shane I don't want to join the "conversation". I put my comment here for reference. For your info "ad hominem" is not always a fallacy. – John Am – 2017-07-19T18:54:23.853

You're comment above is a textbook example of the ad hominem fallacy, viz. denying an argument's conclusion based on the (supposed) characteristics of the person arguing. Ad hominem isn't a fallacy when and only when the character of the person making the argument would actually be germane to evaluating the strength of the premises. That's manifestly not the case here. How would (1) be true when spoken by an atheist, but false if spoken by me? If you think this argument is wrong, then either tell me which premise is false, or tell me which step is invalid. – None – 2017-07-19T19:00:58.803

@shane You reply to a question about pro-life argument from a "secular viewpoint". You justify an erroneous selection of childish arguments. You leave woman's position outside. (full stop) – John Am – 2017-07-19T19:05:59.700

And from a woman's perspective, then, which of the premises is false? What's your evidence? – None – 2017-07-19T19:08:01.663

All are wrong, poorly developed to express the notions – John Am – 2017-07-19T19:13:12.690

Also, to reiterate, I'm not endorsing the argument above. That's a subjective judgment about whether the argument is sound. The original question is whether there are any secular prolife arguments and the factual answer to that question is yes, and I've given an example of such an argument which (I) concludes validly that abortion is wrong, (I) does not rely on any religious premises, and (iii) whose premises are not preposterous on their face. There are lots of respectable pro-choice ways to respond, as you can see in the thread above. Any of (1)-(3) could be and has been denied. – None – 2017-07-19T19:14:48.880

You are not endorsing a "sound argumentation"? Are you an irrationalist? – John Am – 2017-07-19T19:17:02.137

@JohnAm An "argument" consists of a claim that is being proven called the "conclusion" and statements purporting to offer evidence that the conclusion is true called "premises". (1)-(3) are the premises of an argument whose conclusion is that abortion is impermissible. An argument is "valid" if and only if it has the following property: if the premises are true, then the conclusion must be true as well. The validity of an argument is provable, perfectly objectively. But valid arguments can have false conclusions! A valid argument all of whose premises are true is "sound". – None – 2017-07-19T19:27:25.813

I'm saying the argument is valid (and I am provably correct); I am taking no stand here on the more difficult to ascertain question of whether it is sound. There is no general method or algorithm to test for soundness, so evaluating the soundness is inherently subjective. Hence, I don't think such judgments are a good fit for this site. For further reading, cf the Wikipedia entries on "validity" and "soundness". – None – 2017-07-19T19:30:52.230

Ok, well all your premises are wrong, so the conclusion is wrong as well. If the procedure is right then we have a series of nonsensical premises formed in a formula which if the premises had any substance they may appear to have a logical successiveness. But the form of the argumentation is the lesser part of it. Argumentation is about the content not the form. If you treat contemporary ideology with this indifference about the essence of the ideas you propagate I have to tell you that perhaps unconsciously you are becoming an instrument to reactionary causes. – John Am – 2017-07-19T19:38:37.520

And do you have any evidence that the premises are wrong? It's false that it's always wrong to kill a person? Ok which kinds of people do you think it's ok to kill, why, and why do fetuses count? (They aren't guilty of crimes, they aren't combatants in war, etc.) That's your view, which you've clearly spent a long time thinking about, so please explain it all to us, so we can become as wise as you. After all we know you aren't just going to say, "Well that's how I see the world" because then you wouldn't be any more rational than the person who believes the opposite because the Bible says so – None – 2017-07-19T19:44:42.597

Sorry I don't discuss about the Bible, war and soldiers and "pro-life" hypocritic arguments, your favorite choice of subjects apparently. Be well. – John Am – 2017-07-19T20:08:17.673

@shane Even Hitler's life was valuable? No, the premise 1 is BS. It is a life of a good human that is valuable. Then you have to argue that fetus can be classified as a good human. But I guess that will be insanely hard. – rus9384 – 2019-01-29T10:03:50.623

@rus9384, the Pharisees believed that "a good person's life is valuable". But this was refuted because they were hypocrites. – elliot svensson – 2019-01-29T17:00:29.220

@elliotsvensson When you say hypocrites, I guess, you do not mean they truly believed, but only made themselves appear as such. But everyone is a hypocrite, sometimes. I guess. – rus9384 – 2019-01-29T17:21:37.277

You MUST make distinctions between human DNA and HUMAN BEINGS. They are not interchangeable. Human life and human being is also not interchangeable. You must make clear a zygote is not like you and I and is not a human being at that point. You are going to vague and then you attempt to connect dots later. This seems rhetorical in approach and not dedicated to deductive thinking. – Logikal – 2019-01-29T21:45:59.957

1What is a secular reason for premise 1? Additionally, what is the secular response to the claim that personhood does not begin at conception, and it is personhood that makes human life valuable? – yters – 2014-05-02T00:06:56.423

16Secular people can think it's always wrong to kill a person too. They might take that to just be a basic moral fact, for instance. The way to respond to your other point is simply to offer a theory of personhood that turns on some psychological capacities or something. – None – 2014-05-02T03:55:05.520

You are saying personhood begins at conception because a particular psychological capacity begins at conception? If so, that works. – yters – 2014-05-02T03:59:32.133

4The weak point of such an argument is #3, of course - it's better to not destroy anything intrinsically valuable, all other things being equal; but even if we completely avoid the abortion discussion, there are MANY cases where our ethics allow (or even require) destroying something intrinsically valuable if it saves something else [more] intrinsically valuable, or achieves some greater goal/principle. – Peteris – 2014-05-02T07:36:37.477

2@Peteris Agreed. And we don't even have to change the subject: If #3 was indeed an absolute, then medically necessary abortions (to e.g. save the mother's life) would be unethical too. – Voo – 2014-05-02T10:42:52.583

5@yters, I'm not necessarily endorsing any position here, i'm just clarifying some positions that secular folks might hold. People who are attracted to psychological accounts of personhood, usually think that the relevant psychological feature doesn't come until much later in development. Those who think that personhood isn't a basically psychologically phenomenon, but rather one connected to our being certain kinds of biological organisms tend to think that personhood begins early in development, perhaps even at conception. – None – 2014-05-02T12:05:05.037

@yters, A cynic may say that the true purpose of religion is to impose basic morals on the population at large, and thus a non-religious moral person can come to the same conclusions about moral/immoral acts as a religious person. In that sense, many arguments made by religious individuals are essentially (or exactly) the same arguments made by non-religious individuals. – Brian S – 2014-05-02T15:37:31.293

If you're a utilitarian, you don't even need 1 and 3. If life began at conception, then from that moment on any moral decision would have to balance the benefit vs. suffering of the mother and those of the child. So e.g. the mother's suffering would have to be large (great danger to her health, for example) in order to justify the "reduced benefit" to the child. I think even pro-abortion would agree with that, they just wouldn't agree that life begins at conception. – nikie – 2014-05-02T19:03:18.323

@nikie - that's not a pro-life argument, as the mother's life trumps the child's in certain circumstances. A pro-life argument is one that puts both lives at an equal level. – yters – 2014-06-09T23:51:31.700


I think Shane captures the basic structure of the standard secular arguments, but there are a few more that can be offered -- some of which run contrary to the usual political divisions at least in the American sphere.

Regarding your initial formulation, there are a few gaps that I don't really get:

  1. Human existence is inherently good.
  2. A human exists at the point of conception, i.e. that is when her DNA first began to exist.
  3. Therefore, abortion always destroys a human existence, and is always wrong.

Namely, there seems to be something jumbled about what happens in 3.

I would probably formulate this type of argument as follows:

  1. Conception brings into existence a zygote which is a novel human life
  2. We should never take human lives
  3. Therefore abortion as the taking of a human life is wrong.

Formulating in this way, I think, clarifies where the debate really centers in this formulation of an argument. Basically, all the hard parts are in 2 and whether or not we think its true. (You will hear some weird fallacious comparisons between skin cells and zygotes at times, and you will hear some interesting things about implantation [the current medical definition of pregnancy per the AMA] vs fertilization [what most pro-lifers take to be the point where it matters]).

Affirming 2 seems to be the default position. The challenge then would be to deny the prima facie reading of 2 and not wind up with a dangerous view. One method is to replace "lives" with "persons" and suggest that zygotes, embryos, and fetuses are not persons. But then how old does a born child have to be to be a person? Another method is to view human life as a relative good in competition with other goods -- e.g. the environment, personal autonomy, etc. The relative good approach also has some interesting pitfalls. What if a woman is part of dying tribe of people and wants to terminate her pregnancy? Could we then say that the value of diverse human genetics requires her to bring it to term or maybe more so become a baby factory?

But a second completely unrelated line of secular argument can also be offered built around social goods. We could argue that children are a good that belong to the community, and that people have duties to the community and its continued survival. So then those who are able are obligated to participate in community formation through procreation. (It's a socialist argument for babies).

A third line that I've seen advocated both by parts of http://www.secularprolife.org/ and by Matthew Scully who as far as I know is not affiliated with them is that we can link the cause of human suffering to animal suffering and view both as inordinately wrong. In other words, the consistent expansion of the second premise to include at least all mammals regardless of condition.


Posted 2014-05-01T23:29:54.233

Reputation: 23 970

All you know about argumentation is the "Therefore". For your info argumentation is about the arguments. – John Am – 2017-07-19T18:31:15.073

I see a problem with the last one. It is often said that on early stages of fetal development there is no pain. – rus9384 – 2019-01-29T10:32:05.853

@rus9384 I've seen that claim, but with two factors it breaks down. (1) when is "early" and (2) what is "pain". On many of the stricter definitions of pain that would exclude 12 week old fetuses, we would also need to exclude a large number of animals that we usually take to experience pain. / for the early, sure if we go early enough we can say that (I doubt a 128 cell blastocyte experiences anything like anything we call pain), but that's going to really entwine us with the problem of defining "pain". – virmaior – 2019-01-29T13:14:24.897

@virmaior Well, I actually don't think anyone is going to cry or rage when exposed to a scene of an (non-enforced) abortion, as opposed to the scene of war or rape, or etc. That pretty much would exclude that reasoning as being merely a justification and not an actual explanation. – rus9384 – 2019-01-29T13:56:42.710

Actually, I know quite a few people who would. Maybe spend time with people outside your bubble? – virmaior – 2019-01-29T14:39:32.117

Excellent response, thanks! The second line of argument, while it may support some pro-life practices, would not be pro-life in principle. I am looking for a principled secular argument. Your response also confirms what I suspect, that it is no longer very arguable that a unique person comes into existence at the point of conception. – yters – 2014-05-02T02:46:47.963

I do agree the second type of argument would only become strictly pro-life with some further premises I leave out of the sketch, but they can be thoroughly secular in nature. For instance, a mussolini-type racial fascist can believe the Volk needs to reproduce and should not be allowed to abort. / Regarding your last sentence, I'm not sure I follow. Can you expand on what you mean by saying "it is no longer arguable that ..."? – virmaior – 2014-05-02T04:12:07.753

The Volk position like Hitler held is still not truly pro-life, as it favors a certain group of humans. – yters – 2014-05-02T04:15:06.700

In my discussions with people who want abortion legalized, they find it hard to accept that a unique person exists at the point of conception. They find it much easier to accept that a person exists when certain traits develop, such as sensation, cognition, etc. However, if DNA does define these traits, then they exist in a primal manner at the very point of conception. – yters – 2014-05-02T04:16:16.663

1I think it is still very much a point of argument as when we think there's something that deserves a basic right to life at least philosophically. But my sense is that many pro-abortion philosophical arguments start with the conclusion in hand and reject any account that would make abortion unacceptable. So they need ways to claim the zygote is not human life in the relevant sense. So they shift the goal post on what we call life -- but this tends to create odd cases where our intuitions say we shouldn't kill people who are sleeping, etc. but they fail the test as well. – virmaior – 2014-05-02T04:43:07.470

Indeed, I've had this exact conversation with some people. They'll argue abortion is ok because the fetus cannot feel pain, is not self aware, etc. Then I'll ask if it is ok if I kill them when asleep. I've even had one respond with a "Yes!" The lengths people will go to argue for abortion... – yters – 2014-05-02T04:47:53.437

Interesting third point. I've also wondered whether the pro-life position consistently expands to a similar treatment of animals, and what happens when animal life comes in conflict with human life. Or even when it comes in conflict with our way of life, such as our widespread consumption of meat. Is it possible to remain consistently pro-life and a carnivore? – yters – 2014-05-02T05:30:40.857

You can draw some insights from the euthanasia/assisted suicide discussion. It's a bit more straightforward as there is no argument that those people aren't alive; there the whole argument is about if/when/how it's acceptable to take a life, not accepting as an axiom that lives should never be taken. – Peteris – 2014-05-02T07:39:55.913

1@Peteris, I think there are strong parallels, but there are also some interesting differences. Generally euthanasia debates assume the one to die is a person or at least was a person. They can also include questions of the person's wishes and desires (though they can mirror abortion in raising questions about what we desire for them). But there are those who accept the axiom on both sides without qualifications (usually Catholics) followed by those who realize there are times when it is a dangerous line to move. Then there are of course those who have unlimited freedom. – virmaior – 2014-05-02T10:01:18.363

@yters note that the pro-life position isn't necessarily against abortion...just against the idea of it being legal. Subtle difference, but I think it's an important one to clarify your question. I think you are asking "What are secular arguments for the moral objection to abortion"? – DA. – 2014-05-03T02:14:01.643

Yes, that'd be a fair clarification. Along with the fact I'm looking for a principled argument, not a pragmatic one. – yters – 2014-05-03T05:19:39.130


You need an additional premise that destroying something inherently good is always wrong. This can be kind of hard to justify when there are tradeoffs of this sort: destroy X to save Y; destroy Y to save X; do nothing and save neither.

Also, premise 2 is not what most people mean by "human exists". Aside from developmental potential, there is nothing notably different between a two day old human zygote and a two day old mouse zygote (and fish and frogs aren't so different either).

So with the (dubious) premise 4 it would be a valid argument, but the premises would be hard to defend.

Rex Kerr

Posted 2014-05-01T23:29:54.233

Reputation: 15 388

2nd paragraph, "nothing different between a mouse zygote and human zygote": false statement. -1, motion to close. – elliot svensson – 2019-01-28T18:53:18.457

@elliotsvensson - My reply included caveats which you didn't address, and which you edited out of your "quote". This kind of intellectual dishonesty and/or sloppiness is not appropriate in a venue for philosophy. – Rex Kerr – 2019-02-02T22:39:26.063

"Aside from developmental potential, there is nothing notably different between a two day old human zygote and a two day old mouse zygote (and fish and frogs aren't so different either)." False statement, false equivocation, ambiguous and misleading use of the expression "notably different"... -1, motion to close. – elliot svensson – 2019-02-04T14:56:06.900

@elliotsvensson - This comment isn't any more appropriate for the venue than the previous one. One might almost think that you have no idea what you're talking about, and so cannot support your position with any argument or evidence. (Also, you can't give -1 twice, though saying so twice certainly enhances the trollishness of your interactions here.) – Rex Kerr – 2019-02-15T15:08:39.177

@RexKerr, you are using the word "notably" in a misleading way, as if the appearance of a tiny living thing to a person's naked eye has much impact on that thing's true nature... it doesn't. You are dehumanizing people, while I'm only trying to point out a person's flawed argument. – elliot svensson – 2019-02-15T15:11:24.293

@RexKerr, if a mouse were in a woman's uterus instead of a human, I think there would be a big difference. – elliot svensson – 2019-02-15T15:12:31.050

@elliotsvensson - I mean that the key molecular and cell biological events are quite similar, not that they look similar to the naked eye. The critical steps in uterine implantation are similar across mammals; there are some timing and signaling differences, but nothing radically different in kind, just variations on how to coordinate embedding in and growth of the uterine wall. The main difference is immunogenic: a mouse embryo will be attacked by a human's immune system (and vice versa). It's just cells doing common cell-like things, aside from developmental potential, as I said. – Rex Kerr – 2019-02-15T15:22:26.467

@RexKerr, what is your favorite definition for "human"? – elliot svensson – 2019-02-15T15:25:49.493

@elliotsvensson - Depends on the context. If you ask me "is this cell human?" I will look at its genes. If you ask me "does this entity have human rights?" I will look at whether it is functionally human (that is, does it or may it have cognitive and emotional qualities more alike other humans than things to which we do not extend those rights)? – Rex Kerr – 2019-02-15T16:14:34.873

2Good point in your first paragraph. As a response, it is coherent to say that while something is always wrong, it may be the lesser of two evils in certain circumstances. Second paragraph is incorrect, another animal's zygote would not develop into a human if placed in the womb, so they are quite different intrinsically, even if they may appear the same. – yters – 2014-05-02T02:44:09.620

Yes. Visual embryo genesis similarities between vertebrates are misleading. – Java Riser – 2014-05-03T03:29:31.870

1@yters - Good grief, what do you think I mean by "developmental potential"? – Rex Kerr – 2014-05-05T19:40:27.537

@Rex - If you think there are significant intrinsic differences, as I point out, then you contradict yourself saying these differences are not notable. Otherwise, you mean something quite different with the phrase "developmental potential." – yters – 2014-06-09T23:50:18.270

@yters - The point is that the things which make humans specially worth caring about has not yet happened in a two day old human zygote. Potential only gets you so far. – Rex Kerr – 2014-06-11T13:49:30.987

@Rex the point is the difference is not potential, it is actual, i.e. the DNA and other properties of the zygote that differentiate it from other species. Now, if you are saying humans should only be valued based on their usefulness to others, that's an entirely different argument. – yters – 2014-06-11T13:56:51.027

@yters - Typical arguments for the unique sanctity of human life outside of a religious context (as asked for here) rely upon some actual, not potential, capability or experience pertaining to humans. For instance, humans are self-conscious (at least to an extent far surpassing other animals), and pretty much all of Kant's work presupposes a self-conscious actor. A zygote is not self-conscious, so that strategy doesn't work. It can't "suffer" any more than mildew in your bathroom can. You don't ascribe priviledged status to a potato you are about to eat because of its potential. – Rex Kerr – 2014-06-11T15:33:32.897

@yters - So you are left with things like "we have strong feelings for babies because our species would go extinct if we didn't, and we are so clever we know that this ball of barely-undifferentiated cells will become a baby, so we decide to apply the same standards to it"--which is not much of an argument since the same form leads to all sorts of horrific prescriptions (e.g. "we naturally favor opposite-sex attraction so homosexuality is immoral", "we naturally favor our own tribe so war and genocide are okay", etc.). It makes more sense to act as if humans have souls if you believe they do. – Rex Kerr – 2014-06-11T15:40:32.970

@Rex - there are good arguments for a soul outside of a religious context. See Plato and Aristotle. A modern take would be Thomas Nagel. At any rate, now you're onto a different question regarding the secular definition of personhood. Definitely a worthwhile question, and one I'm considering opening since another has expressed interest. Regarding potential, you are confusing the term "potential" with "undeveloped". Potential entails multiple possibilities. A more accurate term to describe the zygote is "undeveloped". – yters – 2014-06-11T22:17:27.863

@yters - I suppose whether one views such arguments as "good" depends on whether one accepts the findings of the scientific revolution. Also, I am not sure what an "undeveloped experience" is, so I think your wording quibble is unhelpful. Call it what you will--it hasn't happened yet, it is not certain to, and one or both of those usually makes a big difference to us. To do otherwise in this case requires a good argument; I am not aware of one which does not look scientifically foolish (or I would have included it in my answer). – Rex Kerr – 2014-06-12T00:15:37.507

@Rex - Well, consciousness will develop provided the normal course of events is not stopped. It's like (though not identical to) someone being asleep and saying it's alright to kill them because they haven't woken up yet, and aren't certain to wake up. Of course, there is an enormous physiological difference between the two cases. However, in both cases there is a biological process in motion that will bring about consciousness at a certain point. Now, before conception this biological process is not in motion, but potentially exists. Hopefully this clarifies my distinction. – yters – 2014-06-12T00:38:47.397

@Rex - I created a question whether there are secular arguments for the soul: http://philosophy.stackexchange.com/questions/14013/is-there-a-modern-secular-argument-for-the-soul

– yters – 2014-06-12T01:02:26.697

@yters - The differences with sleep are pretty important, e.g. you have an actual conscious being (transiently not conscious, but with state stored) vs some cells that will eventually develop into a conscious being if all goes normally. The potato on my plate will also turn into part of a conscious being if all goes normally (e.g. I eat it). Until it's part of me, we don't treat it differently than any other possession of mine (e.g. my fork). – Rex Kerr – 2014-06-12T01:04:47.387

@Rex - Heh, well now I know you aren't being serious if you think a potato is equivalent to a zygote :) – yters – 2014-06-12T01:08:37.313

@yters - Indeed I don't, which is why I reject simple notions of this-will-become-part-of-a-conscious-being as a useful way to ground our treatment of zygotes. "It will happen if you don't mess with it" is insufficient reason to not mess with it. – Rex Kerr – 2014-06-12T01:19:43.543

Let us continue this discussion in chat.

– yters – 2014-06-12T02:15:42.560


I believe there is one additional point that some secular pro-life proponents would argue, namely that there is no intrinsic reason why the mother would have any absolute rights over the life (assuming premise #2) of the foetus. Even if premise #1 does not hold, the new life would have just as much right to request the maternal life to be sacrificed for it's sake as the pro-choice proponents argue that the mater has the right to abort the baby's life, thus creating the following two possible reasonings:

The first:

  1. A human exists at the point of conception, i.e. that is when her DNA first began to exist.
  2. A human wants to live/is intrinsically egoistic.
  3. The wishes of both humans in question are equal, thus taking the wishes of one over the other is 'unethical'.

The second:

  1. A human exists at the point of conception, i.e. that is when her DNA first began to exist.
  2. A human has the right to make it's own choices (which in some way relies on premise #1 from the OP)
  3. A new life can not be asked to make these choices, so it should be protected till the age it can (at which point a secular view still leaves the debate open whether euthanasia/suicide is allowed).

David Mulder

Posted 2014-05-01T23:29:54.233

Reputation: 388

1As for "no intrinsic reason": That thing inside her, "person" or not, has still attached itself to her and is consuming resources that are rightfully hers. If she doesn't want to be pregnant, it is doing so against her will. If any other creature were to do that, it would be called a "parasite" and killed with impunity, because the wishes of the mother are worth more than those of some creature inside her. – cHao – 2014-05-04T01:15:08.893

@cHao: Wait, so let's have the hypothetical case where a man and a 2 year old child are crashed in the jungle. In our juridical system if it is within the capacities of the man in question he would be expected to care for the child, despite it possibly being against the man's will. So indeed, if it would be another creature it would be a parasite, but as we have premise #1 it is not another creature. – David Mulder – 2014-05-04T12:50:27.950

Legally, he is not required to care for the child at all; he is perfectly within his rights to let it die. He's only required not to actively kill it, and even that is only because it is unarguably a person. (And note that if it comes down to his life or the child's, even that prohibition may go out the window.) We tend to expect him to take care of the child...but our expectations are not the law, and for damn good reason. – cHao – 2014-05-04T17:12:07.727

@cHao, actually, he is legally required to [where the child is yours] (which would be the case of a fetus or your own 2yo child crashed in a jungle). There are few if any states or jurisdictions where you are not required to provide care for the physical/medical well-being of a child or other person which you are the guardian of. A fetus or a 2yo is not capable of caring for itself, so the state requires that you do so if it belongs to you.

– user1873 – 2014-05-04T17:27:37.590

2That's why we have laws such as child support. If no one was required to take care of children, the human race wouldn't last too long... – yters – 2014-05-04T17:52:48.323

@user1873: I was assuming the man and child were the only survivors, and were not related. There's not much question about relatives / guardians. – cHao – 2014-05-04T17:53:44.813

@yters: The human race would do just fine without requiring that children be taken care of, because most people are hard-wired to do it anyway. There was no such thing as mandatory child support (or even laws!) until a few thousand years ago at the most, and yet here we are. – cHao – 2014-05-04T18:42:55.457

@cHao, a rather odd assumption, considering that this hypothetical jungle crash was supposed to be analogous to a man's right to make a decision with regard to abortion. I suppose if your argument is that any random man should not have any legal right to decide if any random woman could have an abortion, then they analogy might apply. The child being a parasite to a man after birth is similar to a fetus being a parasite to a woman before birth. To say that a man has no right to decide to abort his fetus, is to deny him a right afforded to a woman. – user1873 – 2014-05-04T18:57:33.443

@user1873: I'm fine with that. The instant a man gets pregnant, he will have the same right to make that decision. For himself, and no one else. – cHao – 2014-05-04T19:29:35.247

1@cHao, I am fine with that philosophically, if you are ok with a man not being required to provide support for his own 2yo in the jungle, or any fetus a woman chooses to keep. – user1873 – 2014-05-04T22:04:06.183

1People aren't robots, and aren't "hardwired" to take care of children. They know they have a moral obligation to do so, and choose accordingly. Some make the right choice, others make the wrong choice and kill and neglect their children. – yters – 2014-05-04T23:06:22.353

Ok, the difference in implementation per country is far bigger than I thought, but what I was talking about was duty to rescue which would at least in a couple of countries of which I know the specific laws also apply to the case I described, however it is true that for example in the US these laws are relatively more "lenient"/specific.

– David Mulder – 2014-05-04T23:07:41.320

@yters: For a great many people, it isn't even a choice. There is an inborn -- ie: hard-wired -- attitude toward children that encourages taking care of them. How else do you think we survived as a species for the hundreds of thousands of years before we developed morality or law? – cHao – 2014-05-05T02:10:37.037

At this point you are bringing in your own psychological theories, and is going off topic. I'd recommend opening a new question. – yters – 2014-05-05T07:40:24.633

@cHao if you do open a companion question on this topic, I'll link it from my question. The question has many interesting corollary issues that I'll be opening new questions. – yters – 2014-05-05T07:47:10.227

@yters: Every mammal species cares for its young to some degree. It's not even theory, it is a known fact. Whether individuals are driven to care for other children is up for debate, but the drive to care for one's own is not. – cHao – 2014-05-05T09:19:48.160


Note: The question posed by the OP above was at one point asking for "secular pro-life arguments", and only later was focused to the analysis of a single of one such argument proposed by the OP. The first part of my response addresses the former question and I will keep it here in that readers may still find it useful. The second part is in response to the currently posed question.

I'm assuming by "secular" argument you simply mean "not based on some religious doctrine but justified through some form of logical reasoning". In that case, in my experience most of the arguments boil down to fetal potential; that you are killing something that has the potential to lead a fulfilling life. Perhaps the most famous to argue this was Don Marquis.

"A Future Like Ours"

Don Marquis argues that abortion, with rare exceptions, is seriously immoral. He bases this conclusion on a theory that he presents and defends about the wrongness of killing. In his view, killing another adult human being is wrong precisely because the victim is deprived of all the value—"activities, projects, experiences, and enjoyments"—of his or her future. Since abortion deprives a typical fetus of a "future like ours," he contends, the moral presumption against abortion is as strong as the presumption against killing another adult human being.

Excerpt taken from Social Ethics: Morality and Social Policy, 7th Edition, by Thomas A. Mappes and Jane S. Zembaty.

Further Supporting arguments for this idea:
Stone, Jim: "Why Potentiality Matters." Canadian Journal of Philosophy, vol. 17, December 1987, pp. 815-830.
Famous Rebuttals:
"A Defense of Abortion" by Judth Jarvis Thomson (Philosophy and Public Affairs, vol. 1, no. 1 (1971), pp. 47-50, 54-66.)
Additional Good reads:
- Majority Opinion in Roe v. Wade by Justice Harry A. Blackmum
- On the Moral and Legal Status of Abortion by Mary Anne Warren

Regarding your proposed argument

It is certainly not a common secular pro-life argument (it's almost identical to the most common non-secular pro-life argument), and the problem lies in that both your premises are not unequivocally true (most secularists would not immediately accept them).

"Human existence is inherently good."
Let's take the first one — good for whom? Good for other animals? I think not. Good for the planet? I think not. Good for humanity? Well that's just a circular argument ("human existence is inherently good for humans to exist"). As we well know, human existence is not inherently good for a lot of things and we do all sorts of harm to each other, to other species, and to this Earth. You might find it difficult to find evidence or convincing reasoning to support your assertion here.

The baser assertion in there is "existence is better than non-existence", and thus and existing thing would be inherently better than a non-existing thing. But this is again just an unsupported assertion. No reason or logic leads someone to that conclusion, it is merely stated as fact. People either accept it or they don't. Seems to me that existence is chaotic, full of pain and suffering and math tests and broken hearts. Sure, there's good too, but non-existence is essentially eternal peace, which doesn't sound so bad...

"A human exists at the point of conception, i.e. that is when her DNA first began to exist"
Your second premise is again difficult to agree with. A human exists whenever a thing meets your particular definition of "human". If you define a "human" as something with it's own DNA, then a blastocyst is human, and that's your prerogative to call it that. The problem with that is that we afford things we define as "humans" rights, and you just gave rights to something with less cells than a corn kernel. Some people might find that a bit ludicrous. There are a lot of good arguments against this line of thought (using the term "human" to describe objects which are very not human-like) so I won't belabor the matter here. Since you read Christopher Hitchens, you should also read his friend Sam Harris, in particular his book Letter to a Christian Nation. It is short, you can read it in an hour, and it talks about this very topic (in addition to other things about religion).


Posted 2014-05-01T23:29:54.233

Reputation: 11 008


Very good question and a really invigorating discussion!! The issue of whether the stages of development from zygote through fetus qualify as "life" or "person" has come up a few times, so I want to contribute to that discussion. I will leave discussion of morality aside.

I have spent years researching and writing about this topic; as a physician, I needed to know with absolute certainty how to define "life" and "person" before I became involved in contraception/prenatal/delivery/postnatal healthcare.  

This is my secular argument that the definitions of "life" and "person" apply to all stages of the human organism's development.

I will use the colloquial term "person." But you can insert "an individual living human" instead of the word "person" at any point, and it will retain full meaning.

There are many situations where the criteria for "life" vs. "non-life" or "person" vs. "non-person" absolutely *must *be defined - at the very least for legality and bioethics purposes. Lacking a clear definition of "life" or "person" results in inconsistencies in discussions on policy and legality.

There is a continuum of possible definitions, many of which would have very different results and implications if selected to define "person." These definitions are necessarily binary; "half-person" or "3/11ths of a person" cannot logically apply.

I need these definitions to be based solidly on logic and scientific evidence.

I refused to accept any definitions the depend on current laws, belief systems, or emotions - these shift and change. The definition of a living member of our species cannot be based upon what is convenient, nor contingent on what we want the answer to be in order to justify how we feel about it.

I am not satisfied with ambiguity when it comes to a definition of human life.


A human organism, like all organisms, passes through stages in its development.

Tracing it backwards from end to beginning:  


  The reason for establishing the zygote as the initial stage of human development is that it is the earliest state in which the organism has its own unique DNA and is capable of independently continuing through the rest of the human development stages (provided there is adequate nutrient media and environment). Regardless of the amount of support, neither an ovum nor a spermatozoon has that capacity individually.

If someone is to define one stage as "person" vs "not-person" (same as for "life" vs "non-life"), then they must define the criteria for the person/non-person distinction. If they are unable to pinpoint the moment in development where that distinction takes place, then they cannot logically define personhood or lack thereof. In that case, either all stages are people, or no stage is a person.

It must be a single moment, for the distinction is binary: person, not a person. Shades of gray like "half-person...3/11ths of a person...17/273rd of a person" make no sense, and therefore do not apply.

For example if we use birth, a process spanning space and time (often lasting hours and a displacement of 12-24 inches), as the criteria for a binary definition, we leave those hours and inches undefined. Any events occurring in that time will also be undefined. That lack of definition causes inconsistencies in discussions on policy and legality. 

Therefore the task is to establish the precise moment of distinction between person/non-person - if there is one.

It is given that an adult, the final human developmental stage, is clearly defined as a person. Then tracing development backwards, what marker is used to determine this abrupt change from 0 to 1?  

Physiologically, when studying the molecular processes throughout the stages of development of zygote through adulthood and senescence, it becomes apparent that all change is gradual.

During embryogenesis changes are most visually striking (as has been mentioned about the early stages looking like other vertebrate embryos). But the developmental processes that began then will end at different times in the life cycle. For example, the growth plates of long bones that begins during embryogenesis won't finally fuse until one's early 20's.

Biochemically, with trillions of chemical reactions going on at different rates in the metabolism of a body comprised of more than 10^27 atoms, with trillions of different DNA transcription and translation processes running at any one instant, is there anything that can be pinpointed as an abrupt change warranting the distinction between being a person and non-person?


The microscopic level is uncertain, so let's take a big step back and look at it macroscopically.  

The common sentiment that birth is the distinguishing factor in defining person/non-person, as we started to discuss, must be examined in detail.


Birth is not a binary state with an on/off toggle switch.

  Tracing backwards from infancy, using the scientific term "organism" to avoid confusion, consider each snapshot in the continuous process of moving from uterus to outside environment:  

  • Organism, fully external, cord severed, placenta delivered (remembering that placenta and cord are fetal tissue), no tissue remaining. ----Nearly everyone would agree that it clearly fits the definition of a neonate.

But if this is the very first moment at which the organism is defined as a "person," then EVERYTHING before that moment must be defined as a non-person.

What about

  • Organism, fully external, cord severed, placenta not delivered. ---Is it a neonate yet? Person or not?
  • Organism, fully external, cord not severed. ---Neonate or fetus? Is it a person yet?
  • Organism, feet still in vaginal canal. ---Are the feet fetus, while the rest of the body is neonate? Is it a 9/10th person?
  • Organism, feet still in cervix, legs in vaginal canal. ---Are the feet fetus? The legs fetus or half-fetus? The upper body neonate? What % of a person is this?
  • Organism, head protruding from dilated cervix. ---Is the head a neonate, the body a fetus? Head of a person with the body of a non-person?
  • Organism, head crowning in dilated cervix. ---Is just the skin on the top of the head a person?

  • Organism, cephalic presentation, station +3, uterus contracting, but cervix not dilated yet ---This is probably clearly a fetus......**But the question remains: *

At what exact moment in the journey between clearly-a-fetus and clearly-a-neonate did it change from non-person to person?  

What about cesarean section?

  Before incision, during incision, after incision but before removing organism, or somewhere in the middle of the motion of removing the organism?

What about the gestational age at delivery?

  A neonate 3 months preterm is born on the same day as a full-term neonate. They have the same birthday, but are at very different developmental stages - 6 months versus 9 months since the zygote stage.

  • Is that preterm neonate still defined as a fetus? It is only at 6 months gestational age, and the full-term neonate was still defined as a fetus at 6 months.
  • Is the preterm neonate a person yet, like the full-tern neonate is? Or does it have to wait 3 months before it becomes a person?    

Why go through this exercise?

This exercise basically asks the question "in the process of that human organism traveling from her uterus, through her vagina, and into the outside environment and severing the cord - when did it become a person?"

This is to illustrate that there is no good boundary. There is a long transition from being 100% in the uterus to 100% out of the vagina; there isn't a toggle switch that flips from unborn to born.

Most of these intermediate options seem ridiculous, but in order to logically say that "birth defines personhood," one of these intermediate stages has to be chosen as the distinction.

This distinction becomes critical in law, because the precise moment of binary change must be clearly defined in order to determine at what point ending the life processes of a human organism qualifies as "killing a person." Intentional infanticide is homicide. Murder. This includes neonaticide - killing within the first 24 hours.

If we leave those hours and inches of birthing undefined, any events occurring in that time will also be undefined. That lack of definition causes inconsistencies in policy and legality. 

Then if we rely on our judicial system to create the life/not-life distinction for us, establishing precedents with each case it reviews, the criteria defining a living member of our species will be dependent on the current views of whomever holds political power at the moment.

An additional note about lacking boundaries: there is much debate in pro-choice circles as to what gestational age limit should be placed on abortions. This "intermediate-options exercise" should be absolutely critical to the success of these discussions - because in order to logically define life or personhood at birth, and also support partial-birth abortion or late-term abortion, one would be required to choose where along the continuum we explored is the absolute "defining moment." But I have rarely seen this discussed.

If we can't precisely define the distinguishing moment of change, we cannot establish solid criteria for life or personhood; therefore, the argument for personhood/non-personhood falls apart.

The only logical binary toggle-switch for the definition of "life" or "person" is the initial stage, when the individual organism first comes into existence - with its own unique DNA and capacity to complete human development. Prior to the formation of a zygote, there are two parental gamete cells with different haploid DNA, both incapable of development independently. That is a distinct biological change.

Rejecting the existence of any other boundary (based upon lack of scientific criteria to establish the distinguishing boundary) may very well be preferable to having a multitude of different ambiguous, poorly defined boundaries.

After having studied embryology, physiology, and aided in numerous vaginal and cesarean deliveries, I can honestly state that none of the intermediate options make sense to me.

A zygote will on its own develop into an adult, as long as nutrients and supportive environment are provided. Remember the placenta and amnion are 100% fetal tissue; the maternal organism supplies nutrients and environment only. An embryo will die without the uterus environment, just as an infant will die without other people taking care of it and feeding it.

Development is true a continuum; there is no moment at which the "life" or "personhood" toggle switch can be defined. Thus the distinction cannot exist.  

Therefore, I consider human life to be a scientific definition:

A human organism is a living organism that develops from a single-celled stage throughout its natural life cycle into adult and senescence, when its life processes cease and it dies.

Living human organism = human life = "person."


Posted 2014-05-01T23:29:54.233

Reputation: 393

1You do realize that this definition would have wide-ranging consequences. Late periods would require forensic examination, to name one, since they could well be negligent homicide. – David Thornley – 2019-01-28T23:37:41.687

@DavidThornley, "would require" is not true. That would be at the district attorney's discretion, and nobody (nobody) would elect a DA to do that. – elliot svensson – 2019-01-29T16:57:15.943

@elliotsvensson In other words, you want a lot of deaths to go uninvestigated, and you have far more faith in DAs than I do. I've seen a lot of cases where DAs went after someone for publicity, or possibly because the DA didn't like the defendant. – David Thornley – 2019-01-30T19:16:27.820

@DavidThornley, there has to be probable cause to initiate an investigation, and the law-enforcement system doesn't peer into such private matters. In many places, they don't even prevent kids from drinking at home, let alone this kind of thing. – elliot svensson – 2019-01-30T20:07:54.637

@elliotsvensson No, an investigation is to find probable cause, and can be started for any reason. The law enforcement system where you are might be sane, but not in the US. – David Thornley – 2019-01-31T03:54:07.900


"[T]hey must define the precise moment at which that person/non-person distinction occurs." (And plenty of almost-repetitions of that.) That's not very philosophical of you. Sorites Paradox. Vagueness.

– None – 2014-05-02T08:34:30.313


Your (quite understandable) desire for clearly demarcated boundaries doesn't imply that the boundaries (if any) are clearly demarcated. This kind of reasoning is called, admittedly somewhat unfriendly (but not meant as such), wishful thinking. If there is a vague boundary, then you'd have to deal with the reality of it somehow. I merely suggest that rejecting a boundary altogether because it might be vague doesn't necessarily follow.

– None – 2014-05-02T10:08:39.157

"adult--adolescent--child--infant--neonate--fetus--embryo--gastrula--blastula--morula--zygote" misses many, many steps. It should read "adult--adolescent--child--infant--neonate--fetus--embryo--gastrula--blastula--morula--zygote--sperm--spermatid--spermatocyte--spermatogonium--germ cell--adult--adolescent--child..." Where do you draw the barrier then? – Patrick Collins – 2014-05-02T10:20:09.393

@DoctorWhom You can ask a question to that extent on this site. If properly phrased as an intellectual conundrum (between 'real' vagueness and a need for clarity), it might be a great question. (Perhaps there already is such a question. I didn't check.) – None – 2014-05-02T10:28:43.047

3To give an example for consideration: as the age of fetal viability continues to decrease with medical technology advances, it may not be all that far off to be having this discussion about a fetus raised entirely to term in an extrauterine environment. Will we then need to change our definition of life to fit that? Should the definition of life change depending on our current progress in technology? – DoctorWhom – 2014-05-02T10:40:01.173

2@DoctorWhom, you might be interested in Robert George and Christopher Tollefsen's book Embryo. It's the best single resource I've seen on the ontology and moral status of the embryo. It's also deeply empirically informed. – None – 2014-05-02T12:51:33.963

2@DoctorWhom note, then, that your argument essentially reduces to: "Life begins at the moment of conception." This is the same bald assertion that everyone else uses, cloaked in less scientific jargon. – Patrick Collins – 2014-05-02T15:44:18.300

I never understand why the assertion is false. The fertilized egg is clearly and independent living organism. It is definitely not the mother, the DNA is completely different. If the fertilized egg were to commit a crime, it would be convicted based on DNA evidence, not its mother. – yters – 2014-05-02T15:54:46.883

1@DoctorWhom, Thanks for this great answer. Also, please link your question when you ask it. I do agree with Watson that your answer is not quite satisfying because you are imposing an external requirement that there be a demarcation point when there may not be one. However, it is great at pointing out the incoherence of making birth a demarcation, and that if there must be such a point it most reasonably begins at conception. – yters – 2014-05-02T15:56:13.870

@yters so if some of my cells mutate and contain DNA different from my own (say, cancer cells) would that make my cancer a human being? – Patrick Collins – 2014-05-02T15:56:56.473

@yters or if I get a skin graft on my hand and then kill someone with the hand having grafted skin, is the donor of the skin to be held responsible? – Patrick Collins – 2014-05-02T15:58:22.243

Does your cancer grow into an adult if you place it in the womb? I really don't understand why these sorts of responses pass as "arguments". And no, you controlled the hand, you are the one responsible for the murder. – yters – 2014-05-02T15:58:58.070

1@yters You said "The fertilized egg is clearly and independent living organism. It is definitely not the mother, the DNA is completely different." My point is that if some of my cells have different DNA, that is not sufficient cause to call them a human being. Hence "having different DNA," which you identified as the sufficient condition for the embryo being a person, cannot be a viable option. Now you seem to be saying "having different DNA in addition to growing in to an adult if placed in the womb" is sufficient, which is equivalent to saying "being a fetus is sufficient." – Patrick Collins – 2014-05-02T16:04:19.767

1That's not a proof of any sort, again, it's just an assertion. Your premises assume the conclusion. – Patrick Collins – 2014-05-02T16:05:16.190

I didn't say that is sufficient to call the cells a human being. I said it is sufficient to distinguish the cells from the mother. The fact that the cells are alive is just a given. I don't know any reputable scientist who'd say these cells are dead. – yters – 2014-05-02T16:07:41.867

1@yters the topic under discussion is whether or not a collection of living cells is a human being -- that's the claim that remains to be shown. Obviously not every collection of cells is a person, or else we would say "tissue samples have a right to life," and we don't. Saying that the embryo has different DNA doesn't show that it is a human being per se. The distinction being made isn't between "living and dead" but "personhood, non-pesonhood" – Patrick Collins – 2014-05-02T16:09:53.427

You claim that "life begins at conception" is just an assertion. The cells are alive, so the question is when they begin to have their own independent life. At the point of conception they can't be the mother's cells because the DNA is unique. Therefore, the cells begin to have their own independent life at the moment of conception. – yters – 2014-05-02T16:12:53.303

Similarly for personhood. We now know the person is defined by the DNA. Therefore, the person comes into existence when the DNA does, i.e. at the moment of conception. – yters – 2014-05-02T16:14:08.263

1@yters if personhood was determined absolutely by DNA, then my skin graft donor would be responsible for my murders and my cancer would be an independent human being. Obviously that isn't the case. – Patrick Collins – 2014-05-02T16:15:43.097

Did the DNA in your skin graft form your brain, like it does in the case of every fertilized egg? – yters – 2014-05-02T16:17:17.370

1@yters So is "different DNA + possibility of eventually forming brain cells" the sufficient condition for personhood? – Patrick Collins – 2014-05-02T16:18:29.747

Nope. Being a fertilized egg is the sufficient condition for personhood. In other words, different DNA + capability of developing into an adult. – yters – 2014-05-02T16:20:18.270


@yters Exactly. This is your premise, and also your conclusion. Consider reading up on petitio principii.

– Patrick Collins – 2014-05-02T16:22:16.017

1I'm not saying that that makes it false by itself, but just that neither DoctorWhom's argument nor your own actually provide any support for it -- they both begin with the assumption "a fertilized egg is the sufficient condition for personhood" and conclude that "every fertilized egg is a person." – Patrick Collins – 2014-05-02T16:29:13.860

4+1 for your nice summary of life beginnings, but it seems like you identified the only binary toggle you could find (conception) and assigned the special significance of "person" to it simply because it is a toggle point. – obelia – 2014-05-02T16:47:55.603

1@obelia, I read his argument more as that if there must be a binary toggle, only conception makes sense. Everyone assumes there must be a binary toggle, so his argument shows that everyone must consequently set the toggle point at conception. – yters – 2014-05-02T16:59:49.157

@PatrickCollins personhood is a different discussion. I'll start another question at some point regarding the secular concept of personhood, and what makes the most sense. I have trouble seeing a coherent alternative to "fertilized egg." – yters – 2014-05-02T17:02:36.240

1Please don't use comments for general discussion! Take it to chat if you want to have a conversation. If you've got an answer, it goes in an answer – Joseph Weissman – 2014-05-02T22:15:48.957

1I think much of the argument could be simplified by saying that if something is X at the end of some time interval, then either it must have become X during that interval, or else it must have been X at the start. Many changes will occur to an egg or an aggregation of cells derived therefrom between the first moment a sperm touches the egg and the time a baby is born. There's some room for argument over exactly which step transforms it into a "human being", though none of the changes that happen late in pregnancy are anywhere near as significant as those which happen earlier. – supercat – 2014-05-05T03:20:01.310


I believe one must discuss the secular pro-life argument form at least two points of view, moral and legal.

Moral argument

1. Human life begins at conception.
2. The destruction of human life is "wrong."
3. Therefore abortion, as the destruction of human life, is "wrong." 

Legal argument

1. Human life begins at conception.
2. The destruction of human life is illegal.
3. therefore abortion, as the destruction of human life, is illegal.

Because we live in an imperfect world/society, the legal argument takes precedence and gives rise to the following argument:

1. In order to continue to exist, a society must enact laws that protect, preserve,
   and benefit its members.
2. Since current members have a limited life span, the laws must not only protect and
   apply to its current members, but also to its **future** members.
3. A future member is created at conception.
4. Therefore society's laws are applicable at the time of conception (of the future

A woman's right over her embryo is not a question of "ownership," but rather a question of "free choice." She can choose not to get pregnant. If she has been forcibly raped, she can choose "the morning after" pill to terminate it. With today's medical advances and medication, there is only one justification to require a medical/doctor abortion, and that is - the life of the mother can be saved only if the pregnancy is terminated. Choosing to conceive, is equivalent to choosing not to abort. You can not have a "do over" because you changed your mind, or it is inconvenient.


Posted 2014-05-01T23:29:54.233

Reputation: 1 686

at last someone mentions legality – Manu de Hanoi – 2019-01-29T16:43:18.720

Your answer is blatantly wrong. Laws can change. Currently the law says Roe vs Wade makes abortion legal. You cannot say legal rights or legal statues over rule objective claims which are MORALS. Morality is and must be UNIVERSAL.That is the answer cannot change ever. So if act x is said to be immoral it is forever OR your first assessment was FALSE that act x is immoral. The same goes the other direction. If act x is moral the value can never ver change. Your use of moral is no different than personal choice. In philosophy this is a no-no. You seem to dislike abortion eventhough it is legal? – Logikal – 2019-01-29T22:07:21.977

@Logikal Note that act x may be different in morality to act x', which very much resembles act x. Shooting someone can be moral or immoral depending on circumstances. – David Thornley – 2019-01-30T19:19:10.467

@David thornley, shooting someone is too vague to make a moral value. Moral values need to be specific when there are specific details in the claim. For instance, shooting and purposely killing a home invader who is unarmed is a legal act but an immoral act. Morality covers all cases of a set of circumstances and it applies all place on the planet. People dont make morals what they are. You cant go from vague to specific and try to prove and justify x. You should be upfront from the start. If you have specific details they must be included. No bringing them up later on someone. – Logikal – 2019-01-30T20:04:02.947

Quite good. One caveat is using a morning after pill contradicts your position, since it kills a fertilized egg. – yters – 2014-09-03T21:04:33.260


I don't see the secular pro-life position as philosophical at all. The filters I will use here are:

  • Pessimism
  • Genetics
  • Novelty

The pessimistic entry point challenges the idea promoted by the Gates Foundation that "every life has equal value", which is optimistic and therefore not rational. (Here rational is used in the sense of Game Theory as the rational strategy as opposed to the superrational strategy.) Clearly every life does not have equal value in the economic sense, and economic factors underlie all mechanisms of life from most simple organisms onward. ("Economic" is used in the broadest sense, not limited to human commerce.) If one were to stop here, there would be no rational basis for a pro-life position. Quite the opposite.

Genetics tells us that diversity is beneficial. This is not philosophical but mathematical, based on analysis of data. Diversity, in the physical/ mathematical sense is "good".

But 6 billion and rising is far in excess of what is needed to maintain a viable level of human genetic diversity. Thus genetic diversity alone is not sufficient.

The benefit of diversity extends deeper in terms of the complexity of the universe, resulting in life, which is a combinatorial process. Here, the system is more than the rules of the system--the rules combined with the elements produce complex and unpredictable outcomes.

Novelty is where every human life has true value, in that each individual has potential. (This is what the Gates Foundation is getting at with their superrational approach.)

The rational strategy is about hedging one's bets to produce expected outcomes. The superrational strategy is about taking risks to in hopes of unexpected ("non--rational") outcomes.

So while the vast majority of humans will never realize their potential in any remarkable way, and the degree of potential may have something to do with genes, one never knows who will be the next Einstein, Heisenberg, Von Neumann, Nash, Kant, etc.

However, this supposes that anything humans do is inherently meaningful, which conflicts with the pessimistic filter. (i.e. actions are meaningful in context, but it goes no deeper than that.)

Reducing it to the most basic form, one might adopt the viewpoint of an automata for which inherent meaning is not a concern. In this conception, that which is is desirable is the greatest possible dataset--the more robust the dataset, the more potentially fruitful the analysis.

Novel data leads to novel insights, and each human life is a novel expression.
Thus all life is valuable as raw data, and human life especially so because of the capacity of the human brain and complexity of the human mind.

Note: The beauty of the pessimistic filter is that, even if overpopulation leads to extinction of the species, an outcome that is not certain, it ultimately doesn't matter. The phenomenal universe as we know it is merely a temporary state between two extremes of entropy.


Posted 2014-05-01T23:29:54.233

Reputation: 413


There is no reasonable secular opinion that opposes all killing outside absolute pacifism, with an obligation to make everyone else pacifist. That is so ideologically embedded that it is really a religious position that may have alternative secular support. If you support any army, you are not actually pro-life, you are just anti-abortion. (And, given how armies are generally constituted, you are more pro-women's lives than pro-men's.)

There is definitely a position based on promoting personal responsibility that suggests that abortion should not necessarily be legal, but that it is surely still not equivalent to murder. If an unwed father is, by default, responsible for his child, if it is born, a mother could equally well automatically owe something to her child.

As most societies sit now, she is not obligated to keep and raise the child. We have provisions like adoption agencies, orphanages, and foster care that make it so that she now has the option to not keep the child. This is truly necessary, as we understand the burden placed on a child by being raised by a parent who cannot cope with it, or who blames it for ruining her life.

So in lieu of having to raise it, she could have to bear it, and the father could still be bound to contribute to the child's maintenance to the degree he is able if it becomes a ward of the state. Her share of this obligation is paid in suffering, and the difficulty she might have separating from the child. And hopefully the investment forced upon either of them might motivate them to keep the child and take on greater responsibility, which would be good for the society as a whole.

This would be a reasonable secular argument for not legalizing abortion. But it would call for far better commitment to the maintenance of the institutions we have that care for children without families. And it would only really justify a punishment for "withholding gestation" as severe as the punishment for withholding child-support.

If your child is separated from you and as a consequence starves and dies, it should not, perhaps matter whether what deprivation causes the starvation is distance from your blood-flow or your money. There may be some degree of relatively deep negligence present but in neither case has there been a murder.

It would also make the man's obligation not subject to the woman's choice, but to his child's luck.


Posted 2014-05-01T23:29:54.233



Granting assumptions #1 and #2 ... #2, at least, seems to follow from what we know about genetics.

I don't think you can 'grant' assumptions #1 and #2.

Granting those assumptions would beg the question.

I don't think that #2 "follows from genetics". You are claiming,

"A human exists at the point of conception, i.e. that is when her DNA first began to exist."

It's debatable what "a human" is, but the humans I've seen all, I don't know, have a head.

So, for example, "No head, therefore not a human!" How's that for logic?

Humans typically have other attributes too:

  • A body
  • Breath
  • Feelings
  • A mother
  • An education
  • Intelligence
  • Language

In fact, these are the kinds of attributes which IMO they need to have, in order to even semi-justify your #1 premise which was, "Human existence is inherently good."

Without or before these things, it's arguably neither "good" nor "human".

Defining a pre-birth fetus or pre-implementation zygote as a "human being" is artificial (perhaps unnatural).

You could perhaps as well define a chocolate bar as human, because the chocolate bar is going to become human after it is eaten!

Defining "human life" as "starting at conception" is if anything a religious argument. Some sources e.g. this rant suggest that even that argument is merely a recent political invention, and that it used to be believed that the soul entered the body at birth (with the first breath).

Furthermore you said, "secular pro-life proponents, including Christopher Hitchens". Did you read his Vanity Fair article which you referenced in the OP? It says,

By rightly expanding our definition of what is alive and what is human, we have also accepted that there may be a conflict of rights between a potential human and an actual one.

IOW according to him a zygote is a "potential" human, not an "actual" one.

I wondered why he said, "rightly expanding". Re-reading the article I can only assume that's the talk about "viability" and "trimesters", IOW perhaps he's claiming that a fetus becomes an actual human after it's developed old enough to be "viable".

He also says, in the article you referenced,

Having once written a mildly “pro-life” essay, I now find (etc.) I resent this crude, uninvited annexation. The decision I took was mine and taken for myself alone.

IOW he says that he is not a "proponent". He's also not rabidly "pro-life": e.g. he said that his mother had abortions without being, in his opinion, murderess.

The top of page 2 says that science has shown that a human can be created by cloning a skin cell (implying that zygotes are analogous to skin cells).


Posted 2014-05-01T23:29:54.233

Reputation: 611

There are many, many humans who don't have all those characteristics. You may not want them to be alive, but that does not mean it isn't good they are alive, nor that they wish they were dead. While Hitchens does not accept the full pro-life position, he clearly ascribes some right to life to the unborn. – yters – 2014-09-17T13:05:30.957

1"Hitchens ... ascribes some right to life to the unborn" -- I infer from the article you referenced that perhaps he ascribes that 'right' at approximately the time when it becomes viable (and thus has both the 'existence' and the 'ability', without which it is difficult to have a 'right'). His doesn't seem to be some kind of pro-life, anti-contraception position. – ChrisW – 2014-09-17T13:25:52.050

@yters Your first sentence seems to be arguing: "You shouldn't want to murder a disabled human; zygotes are equally unable; therefore zygotes are human; therefore you shouldn't want to prevent any zygote from coming to term and being born." – ChrisW – 2014-09-17T13:28:19.810


The answer would depend on the specific moral commitments of a given secular value system. Assuming secular humanism, which (at least in most versions) places a primary value on the experience of being human, the argument would be that abortion damages, weakens, or in some other way acts in opposition to the value we place on human life.

Note that this argument does not necessarily rely on how you categorize a fetus. It could be that abortion damages us as human beings even if fetuses are not human beings. For example, many non-religious people would say that abuse of animals damages our humanity, even though they are not themselves human. Others might say that the destruction of human artifacts, such as books and works of art, damages our collective humanity, although they are not even alive.

Admittedly this argument is incomplete as it stands. It's more of a sketch of an argument than a defensible position. But it would not be hard to expand it into a real argument, depending on what you think is capable of damaging our humanity. It also relies on the idea that our human qualities are valuable, but again, that's a common assumption in secular humanism.

Chris Sunami supports Monica

Posted 2014-05-01T23:29:54.233

Reputation: 23 641


Where are you guys claiming all these secular pro-life people were with these arguments when Savita Halappanavar died?

She was a human organism right? Where were all the secular pro-life people outraged at the loss of her intrinsically valuable life?

Here's a hint folks...if you mare making moral arguments that vary not one whit whether the fetus is in a stainless steel incubator, or a living, breathing, feeling, thinking human...well, if you don't point the disturbing nature of that moral equivalence, it makes it look like you hold it as a premise too. Is that what all of you intend?

Or, to put it another way, everyone's laying out of the necessary premises is clearly missing one, the premise that the pregnant women has no moral standing worth considering, despite being just as much a human organism as the fetus. That one's not supported, and that's the problem with the stance.


Posted 2014-05-01T23:29:54.233

Reputation: 133

3According to the doctors they did not think her life was in danger. That issue is due to a misdiagnosis. If she'd had an abortion yet her baby could have survived, the same needless loss of life would have occurred. – yters – 2014-05-02T05:26:16.333

3The same needless loss of life? Hardly. The fetus would be dead either way, but the mother would still be here if the abortion were allowed. Why do pro-lifers so easily forget that the mother has a life worth considering? – cHao – 2014-05-04T17:46:48.627

1You misunderstand my statement. If the mother's life was not actually in danger, as the doctors thought, yet they carried out an abortion, then there would be a needless loss of life. We can't argue they should have taken an action based on information they didn't know. – yters – 2014-05-04T17:59:05.007

1The mother was pregnant. That means her life was in danger. The fetus was doomed. The doctors sat by and watched, rather than SAFELY end the pregnancy, because they cared more about keeping their hands clean that saving a woman's life. – swbarnes2 – 2014-05-05T00:25:00.557

3@yters: In fact, we can. The entire question is whether that action should be an option even if they aren't sure her life is in danger. A woman is dead because a bunch of cultists saw fit to make laws about what she can do with her own body, and threatened anyone who could have saved her. For a doctor living under laws like that, if there's doubt (and there almost always is), it's safer for him to let her die than to risk going to prison because someone second-guessed his diagnosis. – cHao – 2014-05-06T00:31:37.780