Pain is a natural educator, being one of the most immediate ways to communicate without language. There's no morality I'd care to ascribe to violence, although as sapients we can and ought to be mindful of keeping it proportionate to its cause, as disproportionate violence is not healthy for individuals, demographics, nations, or humanity as a whole. Or... perhaps it is; I don't know. I'd say a lot of legal punishments have been and still are extremely disproportionate, but we maintain ostensibly orderly societies through them. And the Cretaceous-Paleogene extinction allowed us to be here today... sorry, I'm getting to think of violence in cosmic terms; I hope you don't mind. The violence apparent in the universe suggests to me that life is a rather cheap... thing to be spent, almost, as much at odds with our self-awareness as that may be. Given that, of what consequence is a fight between two people? None at all, really. Go ahead and fight —I'm not worried— just don't involve me, as I haven't anything to prove.