Talk radio did not critically wound Congressman Gabrielle Giffords and murder six other people during the shooting rampage in Tucson. Neither did the National Rifle Association, the Tea Party, Sarah Palin, or any of the other persons and institutions whose names we've heard mentioned in the aftermath of the killings.
Jared Lee Loughner, the young man accused of the massacre, is owed the presumption of innocence no less than any other criminal suspect. But if he is found competent and guilty, then he - and he alone - will bear responsibility for his actions, and will have to pay the price for them.
That doesn't mean, though, that the rest of us shouldn't reflect on the horror in Tucson - and, as President Obama proposed last week, honor the victims by striving to be better people, individually and collectively.
Two issues - the vitriolic partisan polarization of our political debate and the easy availability of firearms to unbalanced people such as Mr. Loughner - have dominated the response to the tragedy. I'd suggest another: the way we treat people (or don't) who are mentally ill, as Mr. Loughner gives every indication of being.
Ohio, Michigan, and all other states face tough choices about the public services they offer and how to pay for them at a time of budget austerity. The mental health system inevitably will be targeted for spending cuts.
What are we willing to pay to feel reasonably confident that the system will continue to be able to identify and help others, even as it apparently failed to treat Mr. Loughner? Or is the lowest possible tax bill the most important, or only, concern?
The alleged shooter, we learn, was suspended from college amid doubts about his mental stability, was rejected for military service because he flunked a drug test, and had had numerous contacts with police. Is even an absolutist interpretation of the Second Amendment compatible with the idea that he should not have been able to get his hands on a semiautomatic pistol and a 33-round magazine as easily as he did?
American civilians possess more than 280 million guns. Some 100,000 Americans are shot or killed with guns each year. Isn't it at least worth discussing whether the background check that waved through Mr. Loughner's purchase of a high-powered weapon, and the law that authorized him to hide it as he brought it to a political meeting, need to be tougher?
Or whether the law should allow civilians to own the once-banned extended-round ammunition clip used in the Tucson shootings and similar high-capacity magazines? Or whether it really would be good public policy to allow gun owners to carry concealed weapons in even more places across Ohio?
The more we learn about Mr. Loughner, the more it appears that his rants about government mind control and the gold standard were incoherent, not ideological. So the suggestions immediately after the shooting that he had been directly influenced by violent and intolerant political invective, from the right or left, have not held up.
Still, as Mr. Obama said at the memorial ceremony for the victims, "we are far too eager to lay the blame for all that ails the world at the feet of those who think differently than we do." He was right, and speaking in the proper venue, when he called for public dialogue that heals rather than wounds.
Americans talk a lot about our rights - the Second Amendment right to own whatever firearms we want, the First Amendment right to say whatever we want. We talk much less about the responsibilities that accompany the exercise of these rights.
Discourse in a democracy can, and must, be vigorous and full-throated. It need not, and should not, be apocalyptic. The debate should be based on the strength of our ideas rather than the decibel count of our voices.
Are we - as citizens, public officials, media communicators - prepared to acknowledge that someone who doesn't agree with us about gun control or immigration or health care or Islam or the size and role of government is not by definition an idiot, a liar, a bigot, a traitor, or an evil demon who must be silenced?
Can we concede that someone who disagrees with us may be worth listening to, and may not even be wrong? Will we respect the responsibly expressed opinions we don't share, just as we demand respect for our own opinions?
Are we willing to take ownership of our words, rather than take cowardly refuge in anonymity? Are we as ready to have our ideas and beliefs challenged as we are to attack others' ideas and beliefs - and not lash back, as Ms. Palin did last week, with self-pitying accusations of "blood libel?"
We can refrain from segregating Americans into "us" and "them." We can focus, as the President suggested, on what unites us rather than divides us.
We can discuss our differences without reducing each other to one-word labels that deny our common humanity, or insisting on our own definitions as the only correct ones, or identifying public officials as targets, or proposing "Second Amendment remedies."
Such national introspection and civil conduct probably wouldn't have prevented the most recent tragedy. But they might prevent the next one.
David Kushma is editor of The Blade.
Contact him at: firstname.lastname@example.org