>>589083
I'm in a similar boat as you in that I'm not sure where the line clearly is, but am open to the idea that it is conception
>It clearly can't think or feel
Neither can people in comas, but I think you'd agree that smothering vegetables with pillows is still murder. What about the extremely retarded, would you be okay killing them just because they aren't sentient?
>Sure, it "has the opportunity" to develop, but so did the load you blew on some girl's face.
True, but that load isn't going to do anything on its own unless you scrape it up and fertilize it. A zygote once formed will continue to develop and grow all on its own provided it has sustenance. Also, zygotes are genetically unique and thus clearly distinct from the parents in the way that sperm and eggs are not.
>So at what point does it become immoral to abort a pregnancy? I'd say it's when the fetus is capable of feeling pain. After all, that is the reason why we consider killing, even the killing of animals, to be immoral. If you saw a mat of bacterial slime and dumped acid on it, no one would call you evil. But if you dumped acid on a puppy, they would. So what's the difference between the two? The puppy can think and feel pain. Deliberately inflicting pain upon it is therefore evil. The mat of bacterial slime on the other hand is an unthinking, unfeeling mass of cells.
But sedating someone and killing them in their sleep is also completely painless. Also, how exactly do you define "pain"? Some plants have nerve endings and react to certain kinds of contact as if they feel pain. Even very simple organisms that consist only of a few cells and no nerves at all still feel "pain" of a sort, in that they actively avoid any negative stimuli that they sense, such as extreme heat and cold.
Conception does appear extreme, even to me, but it's also the only definition that I've seen that is wholly internally consistent and stands up to scrutiny. It's a rather unambiguous starting point, and it's the first point at which the new life is genetically distinct from the two parents, and thus clearly not a part of one or the other.