1. I take your cue that you don't want to spend too much time on the point that a fetus is alive, since we agree. I do want to emphasize that much of the public is ignorant on this issue. Confusion on the distinction b/t "person" and "human" does a lot of work here. Many read rejections of fetal personhood as being evidence that a fetus isn't alive, since they lack the context to know the difference. Some confusion also comes from the distinction b/t a "right to life" as opposed to merely being alive.
I encourage you to explore this with people you know, and to ask them directly if they believe a fetus is alive. I spent much of my college years arguing with intelligent people, including biology students, who angrily and persistently argued that a fetus was not alive. This view is casually expressed in media as well. The "clump of cells" formulation is the most common way to express skepticism of fetal life. I think if you listened for that phrasing you'd hear it frequently. But it is possible that my experiences are just different from yours in this respect.
As for the "close to it", I of course agree this is ridiculous. This phrase comes from a podcast hosted by Current Affairs magazine in which one of the editors referred to fetuses as "not alive, or not quite living". This was unchallenged by several of her peers (the editorial staff), and lingers in my memory as an example of incredible ignorance.
In short, my primary audience was not you. Though there are some points in the original article that speak to more informed audiences, such as the historical continuity b/t infanticide and abortion; as well as the point on fetal alcohol syndrome. I am curious if you have thoughts on these.
I am also interested if you believe *death itself* is bad for the *one who dies* or not. Whether or not you do, I am curious to know, and why.
2. This objection comes up sometimes, though usually it is made in reference to gametes (are unfertilized eggs harmed if they aren't fertilized?) The key point here is that there are morally relevant differences b/t a hypothetical human, and an actual human with a hypothetical future (this 2nd category includes you and I).
On this point I wish you had dealt with my final points in my first response. It seems all of our political-moral choices are forward looking and deal with the hypothetical futures of actual humans (and in some cases unspecified hypothetical humans). Various issues such as student debt relief take this form. You could dismiss concerns about young people being burdened with debt and not being able to live a happy future with the appeal to hypothetical people. If indebted millennials are harmed by being deprived of a healthy adult life, then what about people who are never conceived who likewise never have a happy adult life? Or the example I provided in my first response, of an abandoned infant; is it harmed by it's own death by being deprived? I think so. I think your response could lead to nihilism if applied across the board. Are hypothetical futures for actual humans ever morally meaningful for you?
The key here is specificity. When a fetus is harmed by its own death, we have an actual living human with which to identify the harm, just as we would if I died. For hypothetical persons, who exactly is harmed? I struggle to visualize this objection.
You mention "bidirectionality". The stages prior to fetus I don't think are morally relevant for the reasons described above, but you could have also wondered if someone is harmed by their conception being postponed, since they are deprived (assuming those postponing cuts into their total lifespan and doesn't just frameshift it forward in time). I believe so, though I also struggle to visualize this, and the harm is likely to be a matter of a few hours.
Your substitution idea brings in the "branching problem", which is deeply complicated. I'll set that to the side for now. I don't quite see the force of this argument. If you kill me, I am harmed by my own death, and the new human you conceive does not change that fact. Maybe you can offset the aggregate harm, but why was my death necessary for you to conceive a child? Couldn't you have done that anyway? This is unlikely to be able to compensate those who enjoyed me being alive. Is it possible to wait for me to die naturally? I think I need more context to respond to this properly. Who are you compensating with this child? The world? This thought experiment doesn't worry me too much though since this seems to be impossible in real life.
There are alternatives to deprivationism, but it is the majority opinion among philosophers of death, so it is at least "reasonable", even if it might not be the best explanation. The only popular alternative that I am aware of is Epicureanism, which you haven't named explicitly yet.
I look forward to your response.
