Call it the myth of inevitability.

It is the mind-set that says enlightenment and progress are the inescapable byproducts of time. As in a reader who asked last week during an online chat how I thought slavery would have ended had the South won the Civil War. That it might not have ended at all did not enter his calculations. Slavery would've ended, he assured me, through slave revolt "or the onslaught of time/world justice."

It is a common enough conceit, this idea that time inexorably brings change. Whenever I hear it, I am reminded of a passage in Martin Luther King's "Letter From a Birmingham Jail." That attitude, wrote King, stems from "the strangely irrational notion that there is something in the very flow of time that will inevitably cure all ills. Actually, time itself is neutral; it can be used either destructively or constructively."

"Human progress," he added, "never rolls in on wheels of inevitability." So time doesn't bring change. PEOPLE bring change over time.

One of those people, Dorothy Height, died last week. Another, Benjamin Hooks, died a few days before. She was 98, grande dame of the civil rights movement, founder of the Black Family Reunion, fighter for women's rights and, for 40 years, president of the National Council of Negro Women. He was 85, organizer of lunch counter sit-ins during the 1960s, leader of the NAACP for 16 years, and first black member of the Federal Communications Commission, from which perch he pushed for minority ownership of television and radio stations.

One suspects their names are little known to most Americans. Education in history being what it is these days, one is gratified enough when kids can identify King and know that his accomplishments do not include freeing the slaves. But for every King, for every Rosa Parks or Malcolm X whose name is bold-faced in history, there are a hundred who are less well known.

There are a Diane Nash and a C.T. Vivian, a Stanley Levinson and a Bob Moses, a Bayard Rustin and a Fannie Lou Hamer, there are church mothers who walked on feeble legs rather than ride Jim Crow buses, there are children who marched exuberantly past snarling police dogs, there are illiterate sharecroppers who made their marks on voter registration forms in the full knowledge that this act of defiance might cost them their lives. There are envelope stuffers, door knockers and foot soldiers whose names never found their way into history. And there are Dorothy Height and Benjamin Hooks.

We take progress for granted in this country. We stand on the shoulders of giants and think the view is great because WE are so tall. We tend to think — especially if we are black and young — that our freedoms were somehow preordained. OF COURSE we can take any open seat on the bus. OF COURSE we can vote. OF COURSE we can use the library or the park. It's 2010, after all. Time brings change.

Height knew better. When people would tell her the time was not ripe for a given thing, she would challenge them to "ripen the time."

Hooks knew better, too. "I wish I could tell you," he once said, "every time I was on the highway and couldn't use a restroom. My bladder is messed up because of that. Stomach is messed up from eating cold sandwiches. So I can't tell you how I feel about the question, 'Has integration worked?' All these intellectual super-egoists sit around trying to pinpoint where it hasn't. But I have to begin at the fundamental issue that I can drive from Houston to my home in Memphis and stop for a hamburger."

Two great Americans died recently after long lives spent creating the world we take for granted. Lives that remind us human progress does NOT roll in "wheels of inevitability."

Change is a conscious decision.

Leonard Pitts Jr. is a columnist for the Miami Herald. Reach him at lpitts@miamiherald.com.