Violence, like illness, has been with us since long before we were human. But, also like illness, we have made astonishing progress in reducing its prevalence. And there is so much reason for optimism that progress can continue, even accelerate. We no longer (where I am lucky to live) drink water contaminated by sewage. We no longer share public drinking cups. Nearly every place we spend time has a means by which you can effectively wash your hands. We vaccinate ourselves against horrific diseases that used to kill many many people. We do not stigmatize or abandon the ill. As a result, we live much longer, much healthier, much less grief-stricken lives. Violence may be a trickier problem. The capability for violence resides in every one of us, triggered easily or not based on a combination of circumstance and personality. And yet, our individual lives are far safer from violence, as they are from illness, than our ancestors could have imagined. This has been brought about by the rule of law, the mutuality of economics, and (my favorite of the explanations offered in Pinker's "The Better Angels of Our Nature") the expansion of our circles of empathy thanks to technology (from the spoken word right up through Twitter; let's not forget: the ability to live closely with millions of people without dying of infectious disease). But I feel like we are still in the dim, unscientific period of violence reduction. Not two hundred years ago, people thought bad smells made you sick. And avoiding bad smelling places probably went some way towards avoiding illness. The real improvements, though, came with the scientific understanding of germ theory, with antibiotics and vaccines. Today, we try to avoid violence by avoiding (or persecuting, or killing) people we think will be violent towards us (or towards people we empathize with). But every one of us can be that scary other in someone's eyes and there will always be at least a kernel of truth in their fear. Because we are human and humans are capable of violence. So I hope that in the future we will use the knowledge we already have and the knowledge that we surely have yet to gain. That we will do what we can to alter circumstances, like we do what we can to clean our water, so that violence is less easily provoked and is less damaging when it does flare. But we will never be completely safe. Safety is not what we are here for. We will always get sick. We will always die. And I think some measure of violence will always (for any definition of always that is comprehensible) be with us. Which may sound grim, but is actually a source of hope for me. Because it says things are better than they've been and can be better still. And it says, above all, that we don't have to let ourselves react to violence with violence, fear with fear, hate with hate.