Lowly Undergrad, early societies didn't have this idea of reducing violent death to zero - through what mechanism did they acquire this belief, given that they didn't start out with the idea that it was "moral progress"?

I realize it's been years, but - didn't early societies want to encourage peace (in general, since the Hated Enemy obviously needs to be fought) and reduce violent crime? My model of early societies does, in fact, have something roughly isomorphic to "reduce violent death", even if they don't explicitly extrapolate this all the way to "someday, violent death should be nonexistent" - and, let's face it, most modern societies don't really do this either, it's just too far away. Do you have a source for asserting otherwise? Or, if you've changed your mind, do you remember why you claimed this?