Well, the same problem applies to a person. If x regards y as not being a person he can kill y - But that is not ethics, rather it is just subjective (or statical) opinion. An objective, (aka scientific) way to solve the problem is more accurate in its classifications and thus better. We would never click a button to kill something that had a 50% percent chance of being our children, and a 50% chance of being a mouse - even with a million dollars as a reward. Therefore, a scientific definition is better, we must strive to minimize the chance of judging incorrectly. The law of "innocent until proven guilty" also applies here. If there is any uncertainty around your choice to pull the trigger, then you should not do so. As is an idiom in Norway: "it is better than 10 guilty t freed than for 1 innocent to be punished".
...I'm sorry, but I don't understand how this is in any way responsive to my point. My point was that scientific understanding of what something is doesn't necessarily yield how society should view that thing, yet your entirely argument is built on the premise that society should view the unborn in a specific way. The scientific basis for viewing the unborn is just a warrant on the way to that conclusion. That's where I see the problem in your definition: you're basically saying to take societal perception out of the equation by limiting this to a debate about biology, and then adding it back later without recognizing the clear gap. Maybe you think your Point 1 automatically gets you there, but I assure you that it doesn't, and as I see it, the major problem we're going to encounter in this discussion is that we're going to remain lost in these weeds rather than getting at discrete questions regarding the status of the unborn in society and whether or not it should be altered.
Moreover, just because people can have personal opinions about something doesn't necessarily make those opinions the right ones for a society to impose or allow. Pointing out that there are differences of opinion doesn't mean that there is no perspective that is more valid for a society to utilize. If we are concerned about judging incorrectly, then that concern should absolutely include moralistic arguments. Excluding them in favor of a purely scientific analysis simply because it's more straightforward is just oversimplifying what is a very complex problem. I don't see why I should accept your definition simply because there's less uncertainty to it; if anything, I would say that the word "person" giving us more wiggle room is both beneficial to this debate and more accurate to the realities of this topic.
I understand your concern. But it also applies to the term person. Person: A human being regarded as an individual.[1-same as above]
So unless you know what a "human being" is, you cannot decide what a person is. Instead of solving the problem, using the term "person" only deepens the problem. That is because we would have two layers of uncertainty instead of one:
a) what is a human being
b) which human beings are persons.
I see no difference between the two terms, so a change to the words would be a semantic's problem rather than a real solution.
Conclusion: changing the word "human" for "person" cannot solve any of the complications, it just adds a new layer of semantics.
Well, then we have a difference in our understanding of these definitions. If you see no difference between the two terms, then I don't know why you're fighting this, but if you do actually see this as a problem solely built on semantics, then you're clearly not understanding my point. There's value in opening up the discussion to issues of what makes a human being and why that is distinct from just having the qualities of being human. I would argue that this is anything but semantic, though. Knowing when a human starts is one question. Knowing when a human being starts is a separate question because it regards how society should view that human. The term "person" applies a philosophical lens that the term "human" does not. If you want to exclude philosophical discussion just because you don't like the inherent discussion of these terms that comes with that, then you're excluding a large portion of the abortion debate on the grounds that it's too difficult to have. Abortion is a thorny subject, and we shouldn't try to smooth it out to make things simpler when the reality is anything but.
But, again, if you want to use the term human, go ahead. It will focus this debate entirely on biology, and that's my expertise. I'd be happy to engage with questions of what makes a human and how we can delineate. I think it's actually more detrimental to your argument to use the term because a lot of the strength of the pro-life stance resides on the philosophical side of the debate, but if you want to drop that out and try to make the connections to what society should do based solely on biology, then I wish you luck.