@failures art,
Might makes Right.
If I am powerful enough to kill someone and get away with it, I may do so. (IMO of course)
I consider this to be true even when I am the one being attacked.
Reasons for violence can be anything really, emotion, amusement etc.
Killing off individuals recklessly is not beneficial for our society and all that.
And besides, it is rare for me to truly desire someone demise.
I've never really fought anyone let alone kill anyone in case anyone might wonder, hehe.