I am not usually nostalgic for the bad old days. I leave that peculiar form of melancholy and memory to others.

I have friends who look back with fondness at the grammar school teachers they feared and the high school coaches they despised.I know elders who transform the mud and pain of World War II into a landscape of foxhole friendships.

I read memoirs by people who water down the cold anxious hunger of the Depression with the phrase, "Well, we were poor but we didn't know it."

I rarely share such revisionist emotions. The contemporary lens seems more reliable to me than any rose-colored retrospectacles.

But in the past week, I have had two encounters with nostalgia about the worst of times and the best of times.

Once, when I left the movie theater after "The Long Walk Home." Again, when I turned off the television after "Separate But Equal."

These were two finely drawn stories from the central drama of my childhood - the desegregation of America.

One told the legal tale of Brown vs. the Board of Education; the other was about the bus boycott in Montgomery, Ala.

Each ended in a moral victory. And yet each left me oddly sad.

I was not wistful for the Old South. Nor for the terrible struggle over Jim Crow's body.

The nostalgia I felt was rather for a time of moral certainty and great hope.

A time when Thurgood Marshall stood before the Supreme Court arguing that segregated schools were simply evil.

A time when a black maid, Odessa Carter, could do the right thing by walking to work instead of riding on the back of the bus.

A time when the lines were clear and so were the enemies.

I wonder what Justice Marshall thought as he watched lawyer Marshall?

Did he, too, feel a twinge of nostalgia?

In the decades that have elapsed, legal segregation died but racial isolation remained. Legal equality, the precursor to economic equality, promised more than it has delivered.

Today on university greens, some of the children of integration sit in for separate dorms. In the inner cities, some black educators call for all-black, all-male, Afro-centric schools.

Imagine this. In the '50s, civil rights lawyers argued that the psyches of black children were destroyed by segregation.

Now - in either a mirror image or an insult to the moral reasoning of the Brown case - a new generation argues that segregation is the route to black self-esteem.

At the same time, the civil rights cases that come before the Supreme Court today are likely to be about reverse discrimination.

The face of the old enemy may still be visible in political ads about "quotas." But the faces of old allies are full of ambivalence about affirmative action.

In the '90s, they ask, when the middle-class son of a black professional is wooed by colleges, is there a need for racial preference?

But when a trade or corporate board still admits blacks in only token number, can we afford to give up racial goals?

In the debate over fairness, that wonderful word "evil" is rarely heard.

Crack does more damage now, young black men run for their lives from each other and it is far more complicated to talk about racism.

The civil rights leadership, with its eyes on the prize, is often accused of overlooking an underclass.

The younger generation of blacks is split by success as well as failure. They are criticized for not joining a movement they have trouble finding.

Today's problems almost always seem harder than yesterday's.

In the good-bad old days, the issue was access. In the good-bad old days, the work was opening doors.

Now the issues are poverty as well as prejudice. The work is not just getting admission, but truly belonging.

Maybe we are not truly bereft of great civil dramas, just temporarily blind to them.

But in this heroless moment, this causeless time, an era defined by ambivalence, not action, I miss something: the sense of possibilities.

I am nostalgic for the future I once saw, way in the past.