I think it's likely that the civilizing effect of literature has done most of the work, and still continues to do. Look at Steven Pinker's book, The Better Angels of Our Nature: Why Violence Has Declined. It proves beyond any shadow of doubt that violence has declined dramatically throughout the centuries. There are various reasons for it: the rise of the state, Leviathan, the monopoly of violence, children's rights, animal rights. They're all positive signs.
Martin AmisThis (writing) is the love of your life. It's what I want to do when I wake up. Nothing feels so absorbing, so fulfilling.
Martin AmisSo if you ever felt something behind you, when you weren't even one, like welcome heat, like a bulb, like a sun, trying to shine right across the universe - it was me. Always me. It was me. It was me.
Martin AmisLove is an abstract noun, something nebulous. And yet love turns out to be the only part of us that is solid, as the world turns upside down and the screen goes black.
Martin Amis