"Senseless death"-- and its companion, "senseless tragedy"-- is one of the tritest, emptiest phrases you hear. And, sadly, you're hearing it a lot these days, although it's hard to say that anyone's death is in any way sensible, other than perhaps the lucky few who die of very old age on their own terms with friends and family around all their affairs fully settled.

What irks me about "senseless death," though, is not just its emptiness. It's that the phrase almost always is a way to end a conversation, rather than start one. It's a way to avoid uncomfortable conversation about change.

Take, for example, the suicide of actor Robin Williams last week. A google search of his name and the word "senseless" brings up more than two million results, most of them, I'm sure, about his death and not, say, why they're making a third "Night at the Museum" movie.

But what makes his death senseless is not that there's no good explanation for it. There is -- he suffered from severe clinical depression, compounded, apparently, by a recent diagnosis of Parkinson's disease. Up to 20 percent of clinically depressed people attempt suicide, depending on what statistics you consult. The National Alliance for Mental Illness, for example, tells us that half of all those who commit suicide are depressed, and that suicide is, in fact, this country's 10th leading cause of death.

So Williams' death is not senseless because it was unforeseeable, unpredictable, or, in fact, inexplicable. Rather, it is senseless because not one thing will change about the way this country deals with mental illness. Depression (and its cousin addiction, with which Williams also battled) will continue to be treated as an embarrassment rather than an illness. According to a statistics from the Centers for Disease Control in 2011, two-thirds of those with depression -- and they say up to nine percent of us suffer from it -- are not being treated for it.

Same thing with the shooting death of Michael Brown in Ferguson, Mo. Anybody who's even half paying attention to America lately can see pretty clearly that unarmed African American men are getting killed at an alarming rate here. One study puts it at one black man killed every 28 hours by a police officer or someone seeing themselves as a vigilante of some sort.

Dead African American men have become household names: Travon Martin, Jordan Davis, Eric Garner (and Renisha McBride, a young black woman). And now Mike Brown. In one way, of course, none of their deaths make a lick of sense -- they were not armed and not any kind of immediate threat to anyone, let alone those who killed them.

But in another very real way, their deaths are part of a long and tragic pattern going back 450 years, from dead slaves right through to lynchings, anti-black race riots, Emmet Till's murder, Bernie Goetz's subway rampage and the beating of Rodney King.

There might be some positive movement coming out of Brown's death, as there seems to be a growing bipartisan consensus that militarized police departments are a bad idea. But that comes not from Brown's death itself, but from the startling photos of heavily armed police officers intimidating unarmed protestors and journalists, scary photos of military vehicles spewing teargas in American streets.

Aside from that, the pattern suggests that Brown's death will actually change nothing about the way this country treats its non-white youth, and in a week or a month or just 28 hours, maybe, we'll be right back here talking about another dead, unarmed African American. That's what's truly senseless.

I could go on for hours: children dead because parents reject the science of vaccination; Sierra Guyton, the Milwaukee girl dead because some of this city's neighborhoods exist outside the city's capacity to care anymore; kids dead because parents can't be bothered to secure their guns; poor people dead of preventable ailments because Chief Justice John Roberts and Republican governors like Scott Walker didn't want to give Barack Obama a win on health care reform.

In all these cases, it seems like we shrug our shoulders or throw up our hands or make some other gesture that basically means "What can you do? I guess it just doesn't make sense!" But the ignorance is willful and the refusal to make necessary, if difficult, changes deeply dishonors the dead by guaranteeing more death.

In this way, it is we the living who make death senseless.