Scientists may have found a way to eliminate chromosome linked to Down syndrome

The difference is "clear" to you because you are reasoning backwards from a desired conclusion. You want to claim that the zygote is a person and the unfertilized egg is not, so of course the merger of DNA is the "clear" boundary between entities to you.

But this boundary just doesn't work very well. To begin with you ignored the "child with deadly mutation" challenge I presented: the only way the child reaches adulthood is if we modify its genes, which you seem to imply makes it a different entity.

And if we dig a bit deeper, the criterion by which you disqualify the unfertilized egg from being considered human also disqualifies the fertilized egg. It too is an entity which can meld with other entities to form a single entity (chimerism, as we discussed), and it can even do the opposite: identical twins start as one zygote that splits at a later point in its development.

I'm not sure even adult humans would qualify for being human in your worldview, come to think of it. Some people have had their brain halves separated during their lifetime, and this seems to lead to two separate persons locked in one body, at least in some cases (https://en.wikipedia.org/wiki/Split-brain).

At this point, you can start overfitting your definition to draw an absurdly jagged boundary exactly around these counterexamples, but at that point I'd appreciate if you just admit that personhood starting at fertilization is just an axiom for you and everything else follows from it.

> What you're saying seems to be that it's ok for the state to mandate citizens protect the state, but not ok for the state to mandate citizens protect the people in the state.

That is very much not what I am saying, but I wasn't very explicit about the point I was making, so I shall clarify.

Two people can disagree about what they think the law should say, but one thing that all decent people would agree on, is that the law should be consistent. We want it to apply evenly to all, without strange exceptions. We don't want any laws that say "everyone is free, except people born in May, they have to do slave labor in the mines."

I was not making an argument about what the law should be, I was arguing that abortion laws make the law inconsistent, as there is no other case where the state violates the bodily autonomy of one person to force them to care for another. For example, if we are in a remote area and I get badly injured, and you are the only person with a compatible blood type nearby, the state can't force you to donate your blood to me.

My point was that it's inconsistent to say that the state can violate one person's bodily autonomy to keep another alive specifically in the case of pregnancy. If you want to make this consistent, you need to allow the state to do this in all cases, implying among other things forced blood transfusions and forced kidney donations. Perhaps you agree that the state should be able to force people to donate blood or a kidney, and in that case your opinion is consistent.

I wasn't expressing agreement or disagreement with the draft. I was stating that it is irrelevant as a counterexample. That's because the justification for the draft rests on a moral principle that's distinct from the one that justifies abortion laws (ie "citizens' bodily autonomy can be violated to defend the state" vs "citizens' bodily autonomy can be violated to save any individual's life"). Again, I deliberately offer no opinion on whether the draft is justified; for my purposes it's enough to show that it is not relevant as a counterexample.

I'm not making up this boundary. This is the scientific definition of an organism.

>To begin with you ignored the "child with deadly mutation" challenge I presented:

The deadly mutation would be the "problem [that] has happened or will happen to the entity." So it doesn't contradict my previous definition. Regardless of whether the deadly mutation could be fixed by gene modification or not, the child is still a person.

>if we modify its genes, which you seem to imply makes it a different entity.

I don't think I said that.

>And if we dig a bit deeper, the criterion by which you disqualify the unfertilized egg from being considered human also disqualifies the fertilized egg. It too is an entity which can meld with other entities to form a single entity (chimerism, as we discussed), and it can even do the opposite: identical twins start as one zygote that splits at a later point in its development.

I'm not sure either of those contradict my previous definition. The chimerism can be considered a problem that will happen. Regarding identical twins, we could argue whether "grow into an adult human" covers "grow into 2 adult humans" or not.

We can modify the definition slightly to avoid these ambiguities: "Any living entity that is either an adult human, or will/would grow into an adult human as long as no problem has happened or will happen to the entity and the typical development process proceeds."

>I'm not sure even adult humans would qualify for being human in your worldview, come to think of it. Some people have had their brain halves separated during their lifetime, and this seems to lead to two separate persons locked in one body, at least in some cases (https://en.wikipedia.org/wiki/Split-brain).

I'm not sure how that situation in any way would lead to a strange interaction with my definition (old or new definitions). My definition would classify that person as a person.

>but at that point I'd appreciate if you just admit that personhood starting at fertilization is just an axiom for you and everything else follows from it.

The axiom for me is that there's no such thing as a partial person. From that axiom, the only logical conclusion I can see is that personhood begins at fertilization.

>as there is no other case where the state violates the bodily autonomy of one person to force them to care for another.

What about child neglect laws? Those restrict the parents' autonomy.

>For example, if we are in a remote area and I get badly injured, and you are the only person with a compatible blood type nearby, the state can't force you to donate your blood to me.

Generally the state's laws forbid one person from taking actions that would violate the rights of another person. For example, if I'm dying and need a kidney, it's not legal for me to forcefully take a kidney from someone else, even if that's the only way to preserve my bodily rights (avoiding death).

I think that is consistent to the state making it not legal for a mother to kill a fetus (assuming the state views the fetus as a person), even if that's the only way for the mother to preserve her bodily rights.

That's a good point. However, none of the examples of situations where the definition is debatable apply to humans. The page lists viruses, colonial organisms, zooids, and collaboration organisms. I think for humans (which I think is the most widely studied organism), scientists can clearly define what is an organism and what isn't.

I think if you were to survey biologists, the vast majority (95%+) would agree with me on all the cases ("is this specific thing a human organism") you listed.

>"entity" (which is an absolutely load-bearing concept in your definition which, again, you leave undefined)

Ok. Let's define it as "a cell or group of cells that are joined together and acting together".

>You argued that an unfertilized egg cannot be considered a person because it is "clearly" a different entity from the fertilized egg.

I said "I think there's a clear biological difference between an entity receiving nutrition, and 2 entities, each with half of a set of DNA, coming together to make a single entity with a full set of DNA."

My point was that there's a clear difference between receiving nutrition and 2 entities with half a set of DNA coming together. My point wasn't that the unfertilized egg and fertilized egg are clearly different entities (as you've pointed out, that's not exactly clear, and depends on the definition entity).

My definition doesn't hinge on the unfertilized egg and fertilized egg being different entities. An unfertilized egg won't typically grow into an adult human. A fertilized egg will typically grow into an adult human.

>At some point in the distant past, our ancestors were non-human (and, possibly but not necessarily at the same time, not persons). The logical conclusion from your axiom is that there was, at some point, a hard boundary where an entirely nonperson animal gave birth to a "full person" human (and that first human then presumably had to reproduce through bestiality, unless through some amazing fortune another full 100% human being was born and fertile during their fertile years).

That's a good point. One thing though is that our actions today can't impact people in the past. So from an ethics point of view, we don't need to worry about the past, only the present and future. And as you say, we don't 100% know what happened in the past.

With the partial people view, someone might conclude today a person with a certain genetic disorder is similar to an ape, and thus a partial person, and thus doesn't need rights. By saying "no partial people today", we avoid that problem.

>If you believe that it is, your opinion is consistent. If it's not, then you must at least permit abortion in the case of rape, even if the fetus is a person.

I would say the way to resolve this is by defining what is the standard care that each person deserves.

If someone needs an exotic treatment that costs $1B/day to survive each day, and a hospital has the treatment in stock, is the hospital obligated to provide it to someone who can't pay? I would say no. It's within the hospital's rights to not give the person the treatment, or cease treatment if already provided in previous days.

However, is it within the hospital's rights to cease providing the person food and water against the person's will? (Let's avoid the euthanasia discussion and say the person is fully responsive but is quadriplegic.) I would say no. Food and water are standard care, and cannot be denied.

Food and water are standard care. The $1B treatment isn't.

2 people being attached permanently for the purpose of blood processing of a failed kidney isn't standard care.

A mother's womb is standard care for a fetus.

(Another thing to consider is what direct action is taken. In a D&E abortion, the fetus is cut into pieces with a scissors, which is the cause of death. So in the specific case of a D&E abortion, there's a second clear difference from the blood treatment case, in that it's a direct physical attack on the fetus that kills the fetus. E.g. in the kidney failure case, would it be ok to cut the person into pieces with a chainsaw? No, even if the person already is going to die of kidney failure. Other types of abortion are not as direct though, so this argument can't be as clearly used to condemn all types of abortion.)