I last saw John F. Kennedy a little more than 50 years ago, as he rode in triumph down Dublin’s O’Connell Street in the spring of 1963. He was on the last leg of his tour of Europe, having stood just hours before at the Berlin Wall, hurling defiance at the Communists in East Germany. My wife and I stood at the bridge over the River Liffey, along with the tens of thousands of his fellow Irishmen who turned out to see him, the last great hero of their generation.

Now, presidents no longer ride in open cars through the streets of big cities, and I am older by more than a quarter of a century than was Kennedy on that warm spring day in Ireland.

In 1963 I was at the beginning of my career as a college teacher of American history. Since then I have had to confront, as have most American historians in one way or another, Kennedy’s impact on his times and the legacy he left behind. How much of that legacy was style, and how much substance? How much was promise, and how much was achievement? How much legend, and how much myth?

For more than a decade after his death, Kennedy’s friends and admirers turned out book after book, burnishing the image of the gallant young leader of the free world, relishing the glorious spring that ended only with the bitter November harvest.

Today, the legend of the “one brief shining moment” that was the American Camelot has been dimmed. As the Vietnam tragedy unfolded in the late 1960s, it was impossible for any objective historian to ignore Kennedy’s responsibility for some of the decisions that laid the groundwork for an unwinnable war. It was impossible to ignore his initial caution regarding the Civil Rights movement. And it was impossible to ignore the questionable aspects of his personal life, both before and during his presidency.

Kennedy was not the first president to break one of the Ten Commandments (Jefferson, Cleveland, Harding and Franklin Roosevelt preceded him). He was not the first president whose decisions brought on war and tragedy (Lincoln, Wilson, Franklin Roosevelt). He was not the first president to be accused of being mostly show and little substance (Theodore Roosevelt). Yet the images of three of those presidents may be found on Mount Rushmore.

Thousands of Americans each year still flock to the Kennedy library in Boston, and thousands more still visit the gravesite at Arlington. The anniversary of his death has generated yet another cascade of books and memories to accompany the thousands already published.

Is this merely the result of media hype, seeking to reap a commercial profit from a fading memory? Perhaps. But for many of us who lived through those dark days in November 1963, Kennedy will remain a symbol, however flawed, of a different kind of presidency, unmatched by any of his successors. Why?

First of all, this was a president who encouraged public service. The words of his first and only inaugural address: “Ask not what your country can do for you, but what you can do for your country,” spoke not only for the youthful ideals of his generation, but for the old and once-valued tradition of “civic virtue” that goes back to the founders of the republic, who believed that with citizenship came the obligation to serve the greater good.

This was a president who enjoyed and welcomed the give-and-take of open political discussion. His willingness to go before an audience of conservative Protestant ministers to explain why no one should be denied the presidency on religious grounds, his groundbreaking challenge to Vice President Richard Nixon to debate on television and his willingness to hold televised press conferences on an average of every 16 days during his presidency all show confidence and enthusiasm about public discourse. Kennedy needed no handlers, no “spin control” experts, to explain what he said or meant to say. And he needed no teleprompter.

This was a president who — in both his formal and informal speeches demonstrated a level of eloquence that has been all but abandoned by his successors — could quote from the poetry of Robert Frost as well as the words of the Old Testament. This was a president who, having looked into the abyss of a potential nuclear holocaust during the Cuban missile crisis of 1962, could remind his fellow citizens only a few months before his own violent death, “If we cannot end now our differences, we can at least help make the world safe for diversity. For in the final analysis our most common link is that we all inhabit this small planet. We all breathe the same air. We all cherish our children’s futures. And we are all mortal.”

So yes, much of this was indeed symbol over substance. But symbols are nonetheless important. As for substance, we shall never know what the future might have held.

I was in Dublin that November when the news came. It was in the early evening on that side of the Atlantic, and we were preparing dinner for which we suddenly had no appetite. An Irish friend soon joined us as we listened in silence to the Armed Forces Radio while a soft rain fell outside.

There were many Americans who later said that Kennedy’s death affected them more than the death of their parents. The late Theodore Sorensen, who was closer to Kennedy than most, thought he knew why. With the death of a parent, he wrote, people mourn the irrecoverable past. With the death of John F. Kennedy, many of his generation mourned their lost future.

Dr. Lynn H. Parsons taught American history at University College, Dublin from 1962-1964. He is emeritus Professor of History at the State University of New York, College at Brockport, and retired to Maine in 2005. He and his wife live in Castine.