Kennedy Assassination: Bonding a Generation : History: Certain shared experiences shape a generation. “JFK” marks the passing of these memories into the next generation’s myth.

The elderly character on the old radio show--a Mr. Peeby, I believe--had as one of his regular ceremonial duties the task of explaining to Molly (Mrs. Fibber) McGee: “That’s pretty good, daughter, but that ain’t the way I heard it.” The line routinely served to allow a good story to be retold, with variations--and, presumably, comic improvements. Perhaps it was my unfailing pleasure in that weekly ritual that disposed me to become a historian.

For the principal stock-in-trade of historians is the retold story. With the obvious exception of the recent past, there are few new stories under the historical sun. Sometimes the retelling is called “revisionism,” but, by whatever name, the procedure is well-established: A familiar event or person is cast in a new light, occasionally by adducing new evidence, but most often by adopting a new perspective or putting things in a new context--by looking at the Industrial Revolution from the point of view of women, for example, or rethinking the Civil War and Reconstruction in the moral climate of the post-civil-rights era. Day in and day out, in a thousand libraries and a hundred-thousand classrooms, this exercise provides reasonably secure employment for legions of historians--and, one hopes, pleasure and illumination for readers and students.

But what if those readers and students have not heard the story before? Worse, what if they have heard it, but in a distorted rendition? Worse still, what if they have encountered that rendition in a powerful medium like film, with its ever-present potential for propaganda, and its capacity to implant stubbornly lasting images, whether faithful or not to the historical record, in the minds of viewers?

What if the historian’s audience therefore possesses no reliable common fund of knowledge, but only an empty mental bag of ignorance, waiting to be stuffed indiscriminately with error and the bizarre exotica of myth and fable? Despite tenure, and the usually tranquil character of their calling, historians are an anxious breed, and this makes them nervous.

They have been especially roused in recent years by a spate of books, television programs and films that sport boisterously back and forth across the boundary that supposedly separates history from myth. The novels of E.L. Doctorow and Don DeLillo, histories by Gore Vidal, innumerable television “docudramas”--and now, most provocatively, Oliver Stone’s film “JFK”--all inventively blend fact and fiction into heady brews whose potency has many critics deeply agitated.

“Filmmakers make myths,” Stone says unapologetically about “JFK,” setting the critics to clucking. “Here we go again,” they complain. Once more, the ramparts of historical accuracy will have to be defended against the slings and arrows of fabulists. Once more, the canons of scholarship will be invoked against the licentious romancers. Once more, like so many stiff-necked Savanarolas haranguing the Florentine mob, the guardians of historical truth must flourish the knout over the gullible, heresy-prone American public.

Many of those critics are historians. Their protests are studded with pained anecdotage about the lamentable historical ignorance of the young. College students don’t know the difference between the Bill of Rights and the Reign of Terror, they complain. High-school students haven’t a clue who was allied with whom during World War II--whenever that was. No one under the age of 40 knows who (or what) was Estes Kefauver. They think Henrich Himmler invented the Heimlich maneuver and the Wright brothers sang with the Jefferson Airplane. Given such ignorance, so the argument runs, a clever concoction like “JFK” does more harm than good. It stands condemned as a mischievous muddier of the historical waters, a pernicious conflation of myth and history.

It’s a strong indictment, notwithstanding that its makers are so grudging in granting of artistic license. But the indictment takes much of its force from factors usually unspoken. The critics seem unaware that the taproot of their anxiety may lie elsewhere than in their commitment to scholarly accuracy. Their agitation may be traceable not to intellectual imperatives about honoring the boundary between myth and history, but to far deeper psychological needs.

There is myth, there is history, and then there is memory. I suspect that much of the energy that informs the criticisms of “JFK” stems not merely from academic outrage at the confusion of fact and fable, but from the pain of a generation’s violated--and obsolescing--memories.

Every generation has its own memories. Indeed, its recollection of shared experiences constitutes much of what defines it as a generation, giving its members a precious sense of common background and common point of departure for their very particular journey together through the cycle of life. In memory, the mythical and the actual mysteriously commingle, making memory an often unreliable historical source, but an indispensable component of both individual and collective identity.

For my generation--I was born four months before Pearl Harbor, another great molder of collective generational memories--no event serves a more bonding mnemonic role than John F. Kennedy’s assassination. For my parents’ generation, Franklin D. Roosevelt’s inaugural address in 1933 served much the same function; for their parents, perhaps Armistice Day, 1918, or, for my immigrant grandparents, maybe the Easter Uprising in Dublin, in 1916.

Experienced by the young, these kinds of events resonate in their lives forever, serving as ties to all who experienced them at roughly the same stage of life, with similar degrees of understanding, and as markers of the passage of time. Nothing--not all the historical retelling in the world--can substitute for the power of that shared memory. Indeed, the purpose of all the constant retelling is to preserve some vestige of these memories, with little hope of ever salvaging more than just a vestige. History, after all, can never mean more than it did to those who lived it. Quite literally, you had to be there.

It is in this realm, I think, that the deepest sources of unease about artistic works, like the film “JFK,” lie. They are rude reminders that the stuff of our lives is passing out of the exclusive mental clubrooms of one generation’s memory, beyond even the domains of the formal historical record, and into the kingdom of the imagination. That is a wide-open, undisciplined place that requires no generational license to enter.

So when my students, or my children, for that matter, cop to their ignorance of Roosevelt or Kennedy--not to mention Mr. Peeby--I’m not only pained to hear the evidence of their historical illiteracy. I’m more pained to reflect that I’m hearing a dirge for the irretrievable loss of another generation’s felt experience, for the ephemeral passage of a generation’s memories and for my own--and my generation’s--remorselessly funereal advance through the years.