Up too early, so back once more anyway:
A fetus is obviously human, person or not.
A kidney is obviously "human," for a given definition of human, but not a person.
Or, put another way: If it was so bloody obvious this wouldn't be a huge controversy.
Any knowledge of reproductive Biology tells you this. Therefor it is a serious issue, which trees aren't.
Pointing out a switched goalpost from "person" to "human" deals with the RBiology comment. Therefore I point. Though I might comment that you still need to define "human" - are we talking human tissue, a full human err... "person".
Anyway, you're refusing to address the issue actually brought up by the analogy.
Do you have the precise moment a fetus becomes human worthy of protection then?
No. Which is why a law should have a "margin for error." Or, more accurately, a "margin for we don't know the precise moment."
I would make the same choose of course. Lucky that example is so ludicrous that no one would lose sleep over it.
Ludicrous... but illustrative of your philosophical point. Lets confirm it: You think a just-fertilized egg is just as much a person as a one year old child. Morally speaking they can be treated as exactly equal, correct?
You think common fertility treatments involve multiple murders, correct?
IIRC the figure on how many fertilized eggs are miscarried may be as high as 50%. It's a lot. Far, far more common than abortions. Why the silence from pro-lifers of your philosophical stance on that issue? Isn't that a far more pressing concern? (Like the fertility treatments.) It's not like something couldn't be done about it. It'd be intrusive, probably expensive and oppressive, and abstinence outside of intent to have a child likely the only "practical" response... sound good?
(With regard to miscarriages, a common response is "They're not the result of a human intervention and happen naturally." Like someone dying from... well... anything that a doctor saves them from. The point is that if "it's human therefore it must be protected" is your point, then it doesn't matter how "natrual" somethign is." Unless you want to add it? If so we're back to dying when God wants you to... and "It's human" *isn't* an overriding concern. And there's still the fertility treatments...)
Is there anything in science that tells you it's not a person?
Yes. To take the easiest example (and what we were working with) a fertilized egg has no neural activity at all.
Science is stacked against you.... Why else does the abortion places dislike forcing sonograms so much?
Because they seem intended as an intrusive emotional appeal.
It goes like this. All persons have an intrinsic right to life that no one can take away.
I agree.
All live humans have to be persons, otherwise you can have non-persons with no rights like slaves.
No. We simply use a different definition of "persons" and or "humans."
All fetuses are human from the start.
If by "human" you mean "made up of all or mostly human tissue". Sure. Like a severed finger, say.
Therefor are persons because this can't be gained by function,
In dispute. (I can't recall an argument given that isn't circular or simply declarative.) And I'm not really sure what the point is, since I think the physiological ability to function-as-a-person is what pro-choicers generally focus on.
otherwise man decides what that is.
Tough cookies. That's called "Using the brains God gave us."
And deciding "it's at conception"... is making a decision. A lazy and ill-informed one, I maintain, but a decision nonetheless.
So if person hood is gained from function, then man can make others non-persons and justify killing them (jews, blacks ect.).
First, I'm pretty sure at least 1 homicide in history was committed by someone who thought "personhood"/full humanity/whatever started at conception. So I don't think your definition is exactly the road to a killing-free world.
Second, a definition granting "personhood" based on, for example, neurological activity couldn't be withdrawn due to race, class, gender, etc without contradicting the definition.
Yes, it'd be possible to come up with a bad definition of personhood that has bad consequences. For example: "Personhood is present from conception therefore all abortions should be banned." The negative consequences of that definition have already been described ad nauseum. Real world stuff. Not "But if you're wrong based on these dubious unverifiable assumptions..."