It is part of human nature to try to learn lessons from events such as the Tucson shootings, to try to make such tragedies less likely in the future.

One of the lessons being touted to be learned is the need for more civil political discourse.

Now, I'm all in favor of more civil discourse. This column regularly bemoans the senseless hyperbole that characterizes much of American political speech.

There is a very narrow sense in which this is a lesson appropriately tied to this tragedy. The murder of innocent people, and particularly of a child, reminds us of our common humanity and the attempted assassination of a political leader reminds us of our common membership in a polity.

There is a much wider sense, however, in which tying this lesson to this tragedy is not only inappropriate, but counterproductive. Accusing the other side of incivility in a moment of national grief only breeds more incivility.

Moreover, this is not a lesson those touting it are really ready to learn. Take Pima County Sheriff Clarence Dupnik, who did much to launch this unfortunate diversion, as Exhibit A. In his remarks, Dupnik has simultaneously said: (a) those who disagree with him about immigration are bigots; and (b) we really need to reduce the vitriol in our political speech.

The lack of self-awareness on both sides regarding vitriolic political speech is really remarkable. Both sides believe they are just telling the truth about the other guy, but the other side is lying about them.

In reality, vilifying and demonizing political opponents is a staple of political speech by both sides. Neither side engages in it more than the other.

What is being said on the right about Obama is no uglier that what was being said on the left about Bush. Which was no uglier than what was said on the right about Clinton, which was no uglier than what was said on the left about Reagan.

And it has been ever so in American politics. The contention that today's politics is rougher than it has been in the past suffers from an extraordinary case of historical amnesia. A sitting vice president, Aaron Burr, killed a political opponent, founding Treasury Secretary Alexander Hamilton, in a duel for goodness sake.

And I suspect, ever it is to be so. A competitive political system leads to contention. And politics tends to attract those with a blindness toward the other side.

Regardless, this issue is wholly inappropriate to raise in a partisan matter, as it has been, in this context. It is clear from YouTube videos and other evidence that the alleged shooter, Jared Loughner, did not live in our political world, in which Republicans and Democrats say nasty things about each other. He lived in a delusional political world of his own creation, in which the government exercises mind control through grammar and one can invent one's own language and currency.

There has been no evidence that Loughner imbibed in the conservative rhetoric the left is blaming for creating the environment for his violence. But it wouldn't matter if there was. Just as it wouldn't matter if he was found to have a marked up copy of Al Gore's "Earth in the Balance." Or the stories of Mother Goose for that matter.

Loughner, from the evidence, was psychotic. He was disconnected from reality. His interactions with the real world were distorted through his delusional lens.

There may be lessons to be learned from the Tucson shooting tragedy about the treatment of mental illness, the security of our public officials, and the availability of guns. There should be circumspection about even these paths, since they are fraught with uncertainty and tough choices and trade-offs. But they are reasonably related to the event.

However, in this moment of our grief, blaming this tragedy on the political speech of others is not only wrong. It's uncivil.