As historians and journalists downgrade the legacy of U.S. President John F. Kennedy on the 50th anniversary of his death this week, ordinary citizens around the globe will remember a cherished figure.

More than all but the greatest U.S. presidents — George Washington, Abraham Lincoln and Franklin D. Roosevelt — Kennedy is an icon of American political culture. Yet, as New York Times Executive Editor Jill Abramson observed recently, there has never been a major historical work on the Kennedy presidency, a contrast with significant presidents before him and several who followed.

Even contemporary assessments, which are on balance more negative than those of a generation ago, are replete with contradictions. (A personal note: I am chairman of the nonpartisan Profile in Courage Committee at the John F. Kennedy Presidential Library in Boston.)