History does not automatically repeat itself. But recurrent events denote a continuity of basic conditions. There is an underlying logic to human affairs.

So it is appropriate to ask what features of American life work so egregiously to promote assassination attempts on well-known public figures. The more so as the trouble turns out not to be an incurable national proclivity toward violence.

The portrait of the potential assassin is by now well known. The Violence Commission established by President Johnson in 1968 set forth for "the next assassin to strike at a president" the following salient traits:

"Withdrawn, a loner . . . unable to work steadily in the last year or so before the assassination . . . white, male . . . chooses a handgun as his weapon . . . selects a moment when the president is appearing amid crowds." That amounts to a prevision of John Warnock Hinckley Jr., the man charged with shooting President Reagan.

All modern societies tend to throw up such types. By definition advanced countries are on the move. Individuals by the thousands are broken from their moorings and forced to develop new attachments. They experience disappointments galore, and nurse grievances and resentments to the point of frenzy. They focus hatred around national idols, they make a bid for self-asertion by highly visible acts of destruction.

But in other countries -- in Germany and Japan and Italy -- the misfits project their passions around totalitarian movements. Britain and France offer them an imperial mission. But in the United States, they are left to cults or to their own devices.

Weapons are not that much more easily come by in this country than in many others. In the tribal areas of northern Pakistan, practically everybody carries a gun or two. The same prevalence of weapons seems to characterize El Salvador. But the United States is the only highly industrialized country that makes the acquisition of weapons a casual act -- something that can be done by mail or at the corner gun shop. Why?

The answer, I think, lies in a national trait widely recognized as singularly American. It is a quality of unworldliness, a sense of America being a blessed land, a confidence that it is possible to do good and to do well at the same time.

In that spirit, this country has achieved many of its most striking triumphs. We, and perhaps we alone, created a modern industrial state without a whiff of social revolution. We, and perhaps we alone, became a world power without waging major wars of conquest. We, and perhaps we alone, developed a highly educated population without establishing a closed elite.

But the other side of that success is a certain willful blindness, a cultural shallowness, a disposition to expect results without making sacrifices, to imagine that it takes villains to make things go wrong.

In that spirit, almost all of us relentlessly pursue higher and higher living standards based on more and more consumption and less and less saving. But we blame inflation on the government. Almost all of us use gasoline as though it were water. But we suppose that shortages are the fault of the oil companies, or of OPEC.

In the same spirit, we refuse to have Selective Service, and then we blame pay rates or are simply surprised when the Army turns out not to be very good. We elect men of little or no experience to posts of national leadership. Then we attack them because they turn out not to be Cardinal Richelieus.

And in the selfsame spirit, we fight off gun control, honoring in the breach the few laws that do get passed. Then we are astonished and chagrined when the loner the system throws up takes advantage of the national negligence, and gives expression to half-conscious passions in acts of assassination predicted years ago.

The American disease, in other words, is not so much violence as innocence. We marry to the pressures of industrial life the absence of constraints common to the frontier. We pretend there is no connection between violence and weapons, assassinations and guns. We thus pull the wool over our own eyes. And for all the talk of a new era, we are not much different now than we have been ever since our pattern of leadership was disrupted by the assassination of 1963.