Putting aside the fact that there are different sizes of infinities, the latter makes perfect sense to me. It seems counterintuitive because it leads to odd conclusions, like not having a kid has the same moral weight as killing that exact same kid.
It "makes sense" in that it's internally consistent, but it isn't a good way to expect human beings to make moral decisions, precisely because it leads to counterintuitive (and sometimes repugnant) conclusions. For example, if preventing future lives from happening while creating other, DIFFERENT future lives is wrong on net, then we loop back to the conclusion that changing the future is wrong regardless of whether you've altered the past- because altering
the present erases future potential lives just as surely as altering the past would.
I mean, it's easy to provide a moral argument for why destroying a timeline without replacing it is morally wrong, but
changing a timeline shouldn't be morally wrong unless the changes are in some way immoral in and of themselves (i.e. changing history by dropping a nuclear bomb on a city is wrong, but that's because blowing up a city is wrong in itself, not because you changed history by doing it).
Not really. Anything you do which changes the past would be universal genocide. But that doesn't come up as often as you might think. If there is no interference from the future, you are not destroying that future timeline, instead continuing on the one you were already on.
The thing is, then, what privileges the timeline you were "on" from all the other timelines you were "on" that were identical up to the moment at which you made or didn't make that decision?
There's a timeline where, while Dandelor was busily unsealing Jaffur, Kakara took the time to go Spirit Saiyan. There's another timeline where she didn't- namely, the timeline we're playing in.
It's probable that these two timelines are decidedly different in very important ways. By making the choice to go, or not go, Spirit Saiyan, Kakara chose that
one and only one of those timelines would become real to the occupants of her universe, while the other would not. Did this entail 'destroying' a future timeline?
If it did entail such destruction, then either Kakara is not a monster (because destroying one possible timeline and
bringing into being another is a morally neutral act)...
Or Kakara is a monster regardless of what decision she made, because the destruction of a whole universe worth of potential future beings far outweighs any good or bad results directly coming about from the decision itself.
...
I would argue that because of this kind of issue, the assertion "causing a future timeline to not happen is mass murder" leads to absurd conclusions and so is not true. Either that, or "causing a
different future timeline to happen is
the opposite of mass murder, the ultimate good of bringing a zillion new lives into being," and so the 'infinity' terms cancel out in the moral calculation. Whatever you do, you cause (-1 timeline) but you also cause (+1 timeline) as long as you don't somehow blow up the cosmos with a grandfather paradox or something.
This is a common thing in physics- if there are infinitely large terms popping up in your calculations, and your calculations are to be applicable to realistic or vaguely normal scenarios, then the infinitely large terms HAVE to cancel each other out. And, indeed, experience is that when one's analysis is rigorous, they do.
