This is still circular logic. What makes one collection of cells and protoplasm a member of the human species? It is not merely the presence of a particular set of genes/chromosomes - there must be something else.

It is an animal. Severed limbs are not animals. Gametes are not animals. Those are parts of animals. Being a human animal is all that is required to be a member of the human species. The theory of identity at work is “animalism”.

You are saying (or at least it appears that way) that a zygote is a human being because it turns into a human being. But unless you can give some definition/explanation of how to identify a human being this reasoning is circular and vacuous. And as you said elsewhere

I’m saying that a zygote is the earliest stages of a human being’s life. It doesn’t turn into something else. We can identify him as a human being simply because he has human parents. On top of that there is zero evidence that it is some other species, alien, or life form.

Does your reasoning rely on some distinction between “person” & “human being”?

I don’t distinguish the two, personally.

Your normative is teleprompters, celebrities, and slick marketing. Let’s hope it goes the way of the dodo bird.

And it is a living thing.

It isn’t. It does not have any means of reproducing, is not predisposed to functioning on its own, has no metabolism, etc. etc. etc. Given the diversity of life, "organism" is a tricky word to pin down, but an organ doesn't have a single quality of an organism.

If twin A is the same individual as the zygote and if twin B is the same individual as the zygote then twin A is the same individual as twin B.

Twin A is not the same individual as twin B.

Therefore twin A is not the same individual as the zygote and/or twin B is not the same individual as the zygote.

If twin A was the same individual as the zygote and if twin B was the same individual as the zygote then twin A was the same individual as twin B.

Twin A was the same individual as twin B.

Therefore twin A was the same individual as the zygote and/or twin B was the same individual as the zygote.

A placenta is a living thing.

A placenta is an organ of a living thing.

The zygote grew into them, but they are not the same thing, as proven by the fact that each twin is not the same thing as the other.

As it stands you're saying that A is the same individual as C, that B is the same individual as C, but that A is not the same individual as B. That's a contradiction.

They were the same thing at an earlier stage in their development. It is no contradiction if C splits into A and B.

This is such an ambiguous question. Glass used to be sand, but sand isn't glass. Butterflies used to be caterpillars, but caterpillars aren't butterflies. My house used to be a pile of bricks, but that pile of bricks wasn't my house.

Your reasoning that "A used to be B, therefore A and B are the same individual" is fallacious. Identity doesn't work that way.

A used to be A, is my reasoning. It’s a continuum. A doesn’t switch identities at some arbitrary point. You’re the one positing B.

What do you think a living organism is?

Basically any living thing.

Yes, but importantly each twin is not the same individual as the other and so they cannot both be the same individual as the zygote. Therefore either just one of them is the same individual as the zygote (special pleading) or neither is.

The fact that they can "trace their history and existence" to the zygote does not entail that they and the zygote are the same individual.

Sure it does. The facts indicate that they were both the same zygote.

A eukaryotic cell containing 24 distinct chromosomes.

And no human being was every a eukaryotic cell containing 24 distinct chromosomes?

A placenta isn't a living organism. It's an organ. But yes, an individual zygote can split into two individuals. It's why identical twins are identical, or mirror images of each other. In any case, both can trace their history and existence to the one zygote.

Will you state that no human being was ever a zygote? The zygote is just the brief beginnings of a process that does not end until death. The zygote is alive, belongs to the human species, and is an organism. Therefor it is a human being. If not, then what is it?

Uh oh, here's another one:

I’d say that the embryo and the placenta are each their own thing, albeit connected by the umbilical cord. I wouldn’t consider any of these three things to individually be “the human”, and nor would I consider all three of them to collectively be “the human”.

But we can even drop consideration of “the human” here and just consider the embryo. A zygote develops into a blastocyst, and then some of its cells develop into a placenta and some into an embryo.

To say that the placenta is part of the embryo rather than that the embryo is part of the placenta is special pleading.

These arguments are becoming increasingly convoluted. I'm having trouble understanding them.

Both human zygotes and human embryos are phases or stages of a human being's life. They are not their own entities, but the same entity as it continues to grow over time. All adults were teenagers. All teenagers were infants. All infants were neonates. All neonates were fetuses. All fetuses were zygotes. There is just no way around it.

I appreciate the explainer and I apologize for the confusion.

But you're speaking as if placentas, hearts, and lungs were disembodied, as if zygotes develop into them. Placentas, hearts, and lungs, as intimated, are parts of human beings.

I understand your assertion, I just don't follow your reasoning. "All placentas and hearts and lungs were zygotes," therefor, "That a human was zygote does not entail that a zygote is a human".

I've read it again carefully and I don't follow it.

Your reasoning is "Parts of X were A, therefor A isn't X." Flawed doesn't even begin to explain it.

Placentas and hearts were zygotes? I don't follow. The fact zygotes develop human organs seems to me to suggest that they are human, not something else.

All human being were zygotes. That is irrefutable.

I’m sure you can figure that out. But if you go watch one, or look in the mirror, you’ll notice they’re not placentas and hearts.

To be fair it is typical American political pandering. Kamala headquarters noticed they are failing with that demographic, historically so, so their propaganda reflects it. Trump does it with women, the working class, etc.

What does it mean to be a member of the human species?

It means you’re a certain kind of animal, a great ape, and a member of the last extant species of man.

https://en.m.wikipedia.org/wiki/Human

Kamala introduces racist policies, forgivable loans so long as you have a certain skin-color. Media silent.

I'm curious if you'd take issue with hundreds of thousands of Europeans migrating to another continent en masse, perhaps entering countries illegally, and availing themselves of the cultures and systems built by the native populations. After all diversity is a good thing, and perhaps they could use a little.

I ask because the immigration question always seems to flow one way. But it is my belief that there is a fine line between mass migration, colonialism, and gentrification. Mexico city, for example, has been met with an influx of "digital nomads" from the United States, leading to a rise in housing costs for the native populations. Recall the Boer migrations throughout Africa, with the displacement of the original peoples and the bloody wars that resulted. In modern times we have Israeli settlers expanding into Palestine. Diversity is so good that original populations can no longer afford to live there, or worse, are met with violence.

All in all, displacement of the original population is one of the key issues, but whenever someone broaches the topic he is often belittled and dismissed for feeling that way.

Sexist too. What about black women?

She doesn’t need to buy their votes.

ABC fact checks the Kamala campaigns lies about Trump’s most recent town hall.

Kamala introduces racist policies, forgivable loans so long as you have a certain skin-color. Media silent.

Edit: Sorry, wrong thread.

Do you have an aversion to the term zygote?

Not if it classifies a stage of human development. But when it’s posited as a different being, certainly.

Now you are. Morality is strictly to do with how we treat one another. A Zygote is not a 'one another'. This is probably the only intuition of Banno's I think needs no defense. This just, as noted, leads to some hefty bullet-biting.

But it is genetically distinct from the mother. If it’s not another, what is it? An organ? A parasite?

At what point the zygote becomes a 'person', or variably 'baby', 'a human' etc... etc... These are the 'facts' on which most people's positions rely(i have excluded those absolutist positions that are doctrinaire rather than reasoned) and they aren't stable or lets say 'complete' enough to objectively inform us of anything within that grey area as to why we would place the flag 'there'. Yes, we know a lot about zygotes and their development, but which way-point would you choose? It sounds like for you it's conception. Others might be implantation, heartbeat, viability, pain reception among others. But none of these are hard-and-fast in terms of telling us when a 'person' comes into being (or, when that might be morally relevant). I can only really understand taking conception to be the salient point if one is to be, lets say, overly cautious, because of the above indeterminacies. If you're not copping to that, I'm unsure how to make sense of it. But this doesn't seem to me a moral question, anyway. It's similar to saying "well, I can't figure out the precise moral facts, so I'll give it a wide berth". I can't see a real problem in that, other than tryig to make others assent (which you're not doing, so that's fine).

A zygote is a very brief stage of development of an individual human organism, and it will be the same particular entity, a human being, from fertilization onward.

We wouldn't know, or care. That's not a moral consideration.

I wasn’t aware that one needed to know and care if he was being treated morally.

None of this is the case, and the quote you responded to points each out. There is no incoherence. There's just potentially uncomfortable bullet biting.
THe 'vagueness' of the terms doesn't exist. The facts are vague. The terms refer to them. This is no point at which a zygote 'becomes a person'. It does not exist. It occurs somewhere in the grey area and any position has to choose an arbitrary point here if that's what the view is based on.
(though, its very, very much worth noting that 'arbitrary' is not apt here. There are reasons which very much restrict what's acceptable on most views except absolutists ones (i.e killing an infant is also fine, or there is no form of contraception which is acceptable).

What facts are vague? I ask because we actually know a lot about zygotes.

Well, ethics is about what we do. And I'm off to an art exhibit and lunch with friends.

Not something that can be done with a zygote.

Every single one of you were zygotes. Luckily no one treated you with such disregard.

As I mentioned in an earlier post, there is no single point, much like with the Sorites paradox. It's acceptable when it's a zygote or blastocyst or embryo, not acceptable when it's due to be delivered in a day, and in between there's a large grey and ambiguous area as it develops more and more into a human like us.

The only thing grey and ambiguous about it is the position. The vagueness of the terms used to describe it and the arbitrariness of the acceptable time to kill indicate this. This is because the position lends itself to incoherence. I do not think an incoherent belief should be used to justify killing a human being.

There is much more to an organism than its genetic makeup. There are very real, significant, and obvious biological differences between myself and a zygote. Your decision to only consider an organism's genetic makeup is not less arbitrary than my decision to also consider these other important aspects of an organism's being. But I do think that your claim that only an organism's genetic makeup has moral relevance is an absurd one.

The biological difference between you as a zygote and you as an adult was that you were in a different stage of your development. You never once deviated from being this particular human, you still occupy the same location in space and time, no matter what nouns you use to identify the state of your development.

I never once claimed an organism’s genetic makeup has moral relevance. I’ve mentioned many times that I’m speaking about members of the species homo sapiens. I believe members of the species homo sapiens have moral relevance. I’ve never considered the genetic makeup only; I thought it was clear that I was speaking of the entire human organism, because I’ve said as much.

Yes, I’m using the language in the hope that you know what they mean. I’m not sharing with you meaning, or anything weird like that. If we could share meaning, or the words conveyed meaning, you’d understand what I meant even if you didn’t understand the language.

No, you apply your own understanding and meaning to the words. You can do this because you acquired language in your formative years, not because I passed you some meaning with this text.

As long as you understand that a human fetus would develop those complex cognitive functions—indeed was in the process of development—had you not killed it, had you not deprived it of the opportunity. Flies do not.

That’s why the abortionist is treading in murky moral waters. At what stage in that development is killing her acceptable? Do all the complex cognitive functions need to be developed at the same time, or does one or the other function take precedence? It’s all too arbitrary for my tastes, so I personally need a solid unit of value, and its existence suffices enough for me.

So why does anything with our genetic makeup deserve to live?

There is nothing else with our genetic makeup. There is only one extant species of human beings.

None of the things I mentioned are genetically similar to human beings in any way.

Yet these words need shared meaning between individuals for this to be achieved. It need not be ectoplasm, but it needs an inter-subjectivity whereby the words mean roughly similar things. Thus, uniqueness itself is something one must understand to understand others are unique. But then, there is a sameness already built into the language meaning.

And thus, what is this shared "space"? Well, it isn't location, as you say. But there is a sort of type of consciousness that humans share.

"Shared meaning", "consciousness", "inter-subjectivity", "uniqueness", "sameness"—all of these words lack any referent in time and space, despite what the grammar suggests. As such, there is nothing of the sort. Their existence can be seriously questioned, and should they be used as indications of worth and value, the discovery of their non-existence risks leading one to nihilism.

So what distinguishes a human organism with human DNA and a non-human organism with human DNA, and why is the distinction the measure of whether or not it is wrong to kill it?

Which non-human organisms with human DNA are you talking about?

And to be a member of the species homo sapiens is to have the appropriate ("human") DNA? So when you say that it is wrong to kill a foetus because it is human you are simply saying that it is wrong to kill a foetus because it has human DNA.

I fail to see how you get from "the foetus has human DNA" to "therefore it is wrong to kill a foetus".

Many things have human DNA, like sperm or a pool of saliva. Human beings have more than DNA.

Yes. As related to my reply to Hanover above, what a human is depends on how we use the word "human", and how we use the word "human" is a contingent fact about the English language, open to change. If we use the word "human" to refer to anything with human DNA then embryos are human. If we use the word "human" only to refer to sufficiently developed organisms with human DNA then embryos are not human. It is a mistake to commit to some kind of essentialist view of being human such that we can be wrong in (not) using the word "human" to refer to embryos.

And whether or not it is morally acceptable to kill an embryo does not depend on whether or not it is conventional in the English language for the word "human" to refer also to embryos.

We need to look to more concrete facts. These concrete facts are biological, neurological, and psychological. Simply having human DNA is not sufficient biological grounds to entail that the thing "deserves" to live. Whereas being able to think and feel and so on is sufficient biological, neurological, and psychological grounds.

I use the term "human being" in the sense that it is a member of species homo sapiens, whether it is developed or not. A fetus is not of some other species. If a human lifecycle begins at conception, then we are speaking of human life and no other. This is an existentialist and "animalist" view rather than an essentialist view.

The essentialist view would be the personhood one. One is a person so long as she has the essential psychological traits. It implies that persons were never embryos, never in a coma, and other absurdities.

A "sufficiently developed" member of the species homo sapien is no definition of human being that I've ever heard.

Yes, it is always wrong to kill an innocent human being; that’s what such a principle entails. But contrary to your assumption, I wouldn’t think that you believe it is never wrong to kill an innocent human being. You’ve clearly stated otherwise: it is fine to kill an innocent human being if he doesn’t have thoughts and feelings, or isn’t a person.

The differences are, as far as I can tell, you place moral value on what human beings can do, while I place moral value on what a human being is. Is that fair?

I don’t think anything should be outlawed.

What are these "same reasons"?

Because I would say that it is wrong to kill other humans because it is wrong to kill humans with thoughts and feelings and wants. Embryos and (early stage) foetuses don't have thoughts or feelings or wants. They are more like the brain dead living on life support.

It deprives her of life, a future, and the world of her presence. It devalues life, it inflicts unnecessary harm…but mostly it’s unjust. She innocent. She doesn’t deserve to be killed.

Having more or less thoughts and feelings doesn’t make anyone more or less deserving of life or death. So in my mind any such distinction only serves to comfort the killer, not the one who is having his life snuffed out. That’s why the whole ordeal is a purely selfish one.

a) "X is a human" means "X has human DNA"
b) It is never acceptable to kill a human
c) Therefore, it is never acceptable to kill something with human DNA

That’s not my argument, nor have I ever heard it before. Here it is: it is wrong to kill an innocent human being. A fetus is an innocent human being. Therefore, it is wrong to kill a fetus. Which premise would you disagree with?

The biggest and most relevant difference is that a baby is no longer being carried in the womb of its mother, and so for the most part the mother's bodily rights are no longer an issue.

Another significant difference is that the thalamocortical connections that are required for consciousness do not develop until ~26 weeks of pregnancy.

What if the mother wants the child. Does the zygote then deserve a chance at life and become worthy of protection, or is it still disposable?

You've asserted that it is wrong to kill anything with human DNA (except in self-defence, etc.). You haven't justified this.

Yes, it is wrong to intentionally kill a fetus for the same reasons it is wrong to kill any other human being. You can disagree with the premise that a fetus is a human being, or that it is not wrong to kill human beings, but it’s difficult to reasonably do so.