That begs the question. What defines being a "person" other than being alive and being human? Fetuses are clearly both, so you have to add a third restriction. Finding one that works is challenging. It can't be self-awareness because then babies aren't people. Viability outside the womb is a dividing line that will soon be obsoleted by technology.

The long-term justification for abortion will likely have to be rooted in ideas of justifiable homicide (self defense, collateral death during war, etc).

> The long-term justification for abortion will likely have to be rooted in ideas of justifiable homicide

Not at all. Don't define an unborn fetus as a person.

You staged the setup with a question, then only included qualifications that inherently would also include an unborn fetus: alive and human. I say we must include having been born as a requirement to be a person.

The definition of a person no longer includes the unborn. An unborn fetus is an unborn fetus, it is not a person until it is born. There, I just solved your pre-arranged problem.

My question wasn't rhetorical, it was an invitation to offer additional requirements for being a person on top of that the two I presented and think about the merits of those requirements.

Making the third criteria be "being born" works to exclude fetuses, but scientifically it's completely arbitrary. There is pretty much zero developmental difference between a fetus about to be born and a newborn baby. So what's the logic of defining one as a person with a right to life and the other not as a person, other than legal convenience? Frankly I think it's just the byproduct of cognitive dissonance: we want abortion to be okay, but we want killing newborns to be not okay, but the scientific fact is that both are just potential but not actualized sentient self-aware humans.

You sound a bit like one of the engineers you sometimes argue with here. The kind of engineer that wants some area of law to be a black and white rules based system where everything is decided based on a perfectly clean application of logic.

But you know that's not how society works. And it's not how the law works either. There are tremendous grey areas in which rules try to balance competing interests in a way that ends up being, more or less, fair. This balance is based on ideas of messy humans and the culture we've built up over thousands of years. It's not cognitive dissonance when we end up with a rule that is bases on more than the precise scientific inputs. It's just the way our law and culture works.

I'm not saying we shouldn't balance peoples' interests. I'm questioning the background assumptions against which we're doing that balancing. I think "fetuses aren't people because they haven't been born" is a weak assumption.

Don't get me wrong: I think the interests of the mother outweigh the interests of the fetus. Not because fetuses aren't people, but because killing people or allowing them to die is something we do all the time to serve various societal interests.

The logic would be cultural heritage. Birth has always been seen as an immense step, in probably all cultures.

That reasoning would be insufficient for the engineer crowd who would love to replace all laws and human interactions with flow charts, but I don't see why it should be immediately discarded.

In what way are fetuses not people?

Scientifically, they're individual members of the human species.

So are bodies in a grave.

When you sidestep the whole question of "when is a human alive", you're missing the point of the whole discussion.