Animals don't matter?
Do you have a pet sir? If you do, mind if i take his soul and curse him to damnation?

Haha, I see your point. I have 2 cats actually.
What I mean is, killing animals have always been a necessary evil. For food, pelts, might just capture the soul while you are at it

My main point is that it's just weird that noone (in-game that is) is questioning the ethics of capturing souls for your own good.
To doom a person's soul to eternal damnation and madness.
I know now that black gems are considered evil, but noone seems to really care about that either. It's just a loophole to bypass the gods for capturing human souls.
It seems all the intelligent creatures have some kind of god, and regards the soul as something that passes on when the body die. For Nords you enter Sovngarde and so on.
But to capture that soul of someone, even a lowlife as a bandit just seems evil to me. And like I said earlier, noone in-game seems to care about that fact. I haven't found any lore-books mentions it either.
I know some of you say that you just capture the energy of the soul when it leaves the body, but to me, it really seems like you are capturing the soul literally speaking. I'm also basing this on specific quest.
Anyway, I just find this whole concept very interesting