Historian Arthur Schlesinger Jr, has another best seller on the list with his new book, "Robert Kennedy and His Times." Title and theme have produced a political argument. Is it correct to call the late '60s Robert Kennedy's times? Was he the dominant figure of that era?

A lot of people I respect have pointed out that there's nothing to this thesis except Schlesinger's subjectivity. The dominant figure of the era, they say, was Lyndon Johnson.

They have a point, Johnson was the president. Johnson ran the war. Johnson was the mover and shaker behind the civil-rights legislation. He deserves the credit for that, and he certainly reaped the backlash.

"Patiently endured so long as it seemed beyond redress, a grievance comes to appear intolerable once the possibility of removing it crosses men's minds." Tocqueville said that. Johnson learned its truth.

Moreover, those same critics add, even if it is considered that the anti-war movement became the dominant theme of the late '60s, it was Eugene McCarthy and not Robert Kennedy who first gave that movement political voice.

Again, they have a point. It was McCarthy who rolled up the big anti-Johnson vote in New Hampshire while Kennedy was chewing his nails.

Nevertheless and despite the validity of the critism, it seems to me that the Schlesinger thesis is accurate, though he never explicitly states it. I think the late '60s were the times of Robert Kennedy and will be remembered as such because he made his country aware that it was slipping and because he was uniquely qualified to do so.

There have always been two strains in Americans history. There is, on the one hand, the American dream that is best summed up in Jefferson's Declaration and in Lincoln's speech at Gettysburg: equal opportunity, equal justice and the notion that we are all one family, embarked on a long journey that will test us through time.

And on the other hand, we have always had a streak of violence and bluster: "Not one cent for tribute," brinkmanship, Vietnam, the cold war, "We're No. 1."

I like to think that the first strain represents the better as well as the more documents side of the national nature, but the odd thing about Robert Kennedy was that he came straight out of the second strain to make himself the leader and spokesman for the first.

The tough kid, the son of a tough tycoon, the aide to Joe McCarthy, the man who could run a missile crisis and advise retribution for failure at the Bay of Pigs became the man who could calm rioters by quoting Aeschylus and who seemed, at the very height of one of the most violent epochs in our history, to feel all the pain, understand the suffering, almost to take it into himself and so to unify us.

With the possible exception of Theodore Roosevelt, I don't know any figure in American history who so combined those two national strains. Kennedy was a tough guy with a big stick. He was also enlightened, sensitive, liberal.

In that sense, it seems to me fair that Kennedy was the dominant figure of his time, although the time was a brief one. True that Johnson was president. But Johnson never understood his country and admitted it when, in effect, he resigned. True that the courageous McCarthy was the first public figure to make opposition to the war politically respectable. But Kennedy was the man who finally seized the moment in American history when we began to realize that, in Vietnam, we had given way to the darker side of our nature and were in danger of surrendering our dream.

He seized that moment and made us think about it. People say it was tragic that he died. But it was lucky that he lived.