NASHVILLE -- - John Seigenthaler should write a book.

Actually, Seigenthaler, former aide to Attorney General Robert F. Kennedy, has authored several books, including one on Watergate. But as near as can be gleaned, from a search of Amazon.com, he has yet to write the book he ought to write. Meaning, a book that struggles with a question that seems, in some ways, to have haunted him most of his life.

What does it mean to be a white person of conscience in a racist nation?

It is a question that is applicable to millions, of course, yet one that has seldom even been posed, much less grappled with in any meaningful way. Seigenthaler is uniquely qualified to do both.

This becomes clear in a poignant meeting with the 2011 student freedom riders at the First Amendment Center that bear his name. He is a decent man. You get that sense. He's the one the attorney general dispatched to the south to rescue the freedom riders after a bus was burned and a mob set loose on the defenseless college students who committed the "crime" of riding interracially on interstate buses. He is the one who took a pipe blow to the back of the head while trying to rescue two young black women from that self same mob.

So a decent man, yes. But he is a decent man who, not unreasonaby, still wonders, 50 years later, at 83 years of age, how the tragedy of American racism could have been so invisible to him and his contemporaries until movements like the freedom rides forced them to see. How could something that seems so obvious now have been imperceptible then?

"I think back to my childhood," he tells the students. "Those two (African American) women, Lela Gray and Birdie Mai Liddle, at times were surrogate mothers to my siblings and me. And they were treated with great respect in my home. Once they were on the street and in a crowd…I don't mean I wouldn't have recognized them if I had seen them or been courteous to them or caring for them.

"But I will tell you, like Ellison said, they were invisible. I don't know how many times I was on a bus or trolley car when I was a child or young adult, not paying any attention to the signs. Lela Gray or Birdie Mai Liddle, Rosa Park's counterparts here, paid their fare, and went where the signs told them. Some were carrying (burdens) maybe taking laundry home from some white woman's kitchen to press it during the night and get it back in the morning. They struggled to the back, where they had to go. My parents had told me, if a lady needs a seat, stand up and give her your seat. It never occurred to me they meant a black lady. And indeed, my parents never meant a black lady.''

He is perched on a stool in the front of the small room, arms folded over his chest, eyes turned inward, reflecting. "Until you read Ralph Ellison,'' he says, "you don’t' understand what the invisible man or the invisible women really were. We who are white, maybe went out of our way not to see them, but we didn't see them. That's not entitled to absolution. It's a condemnation of our ignorance.''

There is wonder in his voice. "I look back at that time,'' he says, "and that's when I say, where was my head, where was my heart, where were my parents' heads and hearts? Never heard from my teachers about the indignity, the indecency. Not one time did I ever hear a sermon in my childhood or young adulthood, directed in any way at the injustice of a society that separated people by race. It was part blind ignorance and part blatant arrogance. And I confess that with great and deep regret and if I could change it, I would. But you know, I'm 50 years too late from the time I first really started intensely thinking about it.''

You sense the soul struggles of a good man who will probably go to his grave wondering how the society, the very soil from which he sprang, could have gotten so much so tragically wrong.

In 1899, Rudyard Kipling wrote a poem "The White Man's Burden,'' in which said burden was described as a colonizer's obligation to the welfare of the colonized nation, "your new-caught, sullen peoples.'' If Seigenthaler is any example, though, it might be argued that the white man's true burden - at least, the burden of the white man who regards himself as decent, enlightened, moral, good - is to figure out what to do with the legacy of injustice that attaches like glue to the very concept of whiteness in America.

Many years ago, the late Michael Browning, a white Miami Herald reporter, wrote of his encounter with Rev. C. T. Vivian, an aide to Martin Luther King Jr., who spoke of how he asked his white seminary students if they had ever prayed for forgiveness for the sin of racism. Browning felt indicted by the question.

"Southern irresolution,'' he wrote. "How, if I am as benevolent as I think I am, can black people see me as such a monster? Am I an inert part of some vast weighty boulder of oppression? Do I injure blacks by breathing and just being white?"

And the answer is probably less important than the asking.

"You know," says Seigenthaler, "it was a cliché, maybe, when Jack Kennedy said each of us can make a difference. But it's no cliché to say each of us should try."

He grieves of things that were invisible to him a lifetime ago. Perhaps the only sensible and moral response then, is to wonder: What things are invisible to us now?