We’ve made some progress in understanding mental illnesses over the past few decades, and even come up with drugs to help ameliorate their effects. But we have not made any headway against suicide.

According to the World Health Organization, global suicide rates have increased by 60 percent over the past 45 years. The increase in this country is nothing like that, but between 1999 and 2010, the suicide rate among Americans between 35 and 64 rose by 28 percent. More people die by suicide than by auto accidents.

When you get inside the numbers, all sorts of correlations pop out. Whites are more likely to commit suicide than African-Americans or Hispanics. Economically stressed and socially isolated people are more likely to commit suicide than those who are not. People in the Western American states are more likely to kill themselves than people in the Eastern ones. People in France are more likely to kill themselves than people in the United Kingdom.

But people don’t kill themselves in bundles. They kill themselves, for the most part, one by one. People who attempt suicide are always subject to sociological risk factors, but they need an idea or story to bring them to the edge of suicide and to justify their act. If you want to prevent suicide, of course, you want to reduce unemployment and isolation, but you also want to attack the ideas and stories that seem to justify it.

Some people commit suicide because their sense of their own identity has dissolved. Some people do it because they hate themselves. Some feel unable to ever participate in the world. The writer Annie Sexton wrote the following before her own suicide: “Now listen, life is lovely, but I Can’t Live It. ... To be alive, yes, alive, but not be able to live it. Ay, that’s the rub. I am like a stone that lives ... locked outside of all that’s real. ... I wish, or think I wish, that I were dying of something, for then I could be brave, but to be not dying and yet ... and yet to [be] behind a wall, watching everyone fit in where I can’t, to talk behind a gray foggy wall, to live but ... to do it all wrong. ... I’m not a part. I’m not a member. I’m frozen.” In her eloquent and affecting book “Stay: A History of Suicide and the Philosophies Against It,” Jennifer Michael Hecht presents two big counter ideas that she hopes people contemplating potential suicides will keep in their heads. Her first is that, “Suicide is delayed homicide.” Suicides happen in clusters, with one person’s suicide influencing the other’s. If a parent commits suicide, his or her children are three times as likely to do so at some point in their lives. In the month after Marilyn Monroe’s overdose, there was a 12 percent increase in suicides across America. People in the act of committing suicide may feel isolated, but, in fact, they are deeply connected to those around. As Hecht put it, if you want your niece to make it through her dark nights, you have to make it through yours.

Her second argument is that you owe it to your future self to live. A 1978 study tracked down 515 people who were stopped from jumping off the Golden Gate Bridge. Decades later, Hecht writes, “94 percent of those who had tried to commit suicide on the bridge were still alive or had died of natural causes.” Suicide is an act of chronological arrogance, the assumption that the impulse of the moment has a right to dictate the judgment of future decades.

I’d only add that the suicidal situation is an ironical situation. A person enters the situation amid feelings of powerlessness and despair, but once in the situation the potential suicide has the power to make a series of big points before the world. By deciding to live, a person in a suicidal situation can prove that life isn’t just about racking up pleasure points; it is a vale of soul-making, and suffering can be turned into wisdom. A person in that situation can model endurance and prove to others that, as John Milton put it, “They also serve who only stand and wait.” That person can commit to live to redeem past mistakes. That person can show that we are not completely self-determining creatures, and do not have the right to choose when we end our participation in the common project of life.

The blackness of the suicidal situation makes these rejoinders stand out in stark relief. And, as our friend Nietzsche observed, he who has a why to live for can withstand any how.