You said:
The question is not whether the fertilized egg is "alive," but whether it is legally and ethically "human."
That question is only difficult if someone doesn't think logically. If a fertilized egg is where nature wants it to be, there's only a matter of time before it is inarguably a human. It will never become an eggplant, a pebble, or a dog's nose. Or a nothing. Your body was once a fertilized egg, as were the bodies of everyone reading this thread.
It's just sophistry to say that a fertilized egg is anything but a tiny human being.
> If a fertilized egg is where nature wants it to be, there's only a matter of time before it is inarguably a human.
Nonsense. A great many fertilized eggs get just naturally flushed down the tubes, as it were. Just because an egg gets fertilized doesn't mean it's gonna take.
> It will never become an eggplant, a pebble, or a dog's nose.
Ah, but here's the thing: it just might become someone else's new neurological system or some such.
> Your body was once a fertilized egg, as were the bodies of everyone reading this thread.
My body was once an *unfertilized* egg, too.
Dna probes or HLA typing would prove that it is.