When White House Chief of Staff Rahm Emanuel last month characterized a plan by liberal activists to air attack ads opposing conservative Democrats as "retarded," he did not need the expletive that preceded the term to offend many. The word "retarded," when used in this way, is unacceptable. Not only does it hurt vulnerable people, but it cheapens us, and Emanuel may well spend a good part of his career apologizing for his callousness.

But let's be honest here. Who among us has not used the term "retard" among friends, in safe circles, never to be quoted or even attributed? We laugh it off, excusing each other's bad taste. The most sensitive among us wince and look the other way.

There's no denying the power of language to define or wound. Almost all of us occasionally use expressions that demean, based on race or gender or mental health.

What do we say then? "Mentally challenged" is a little too politically correct for my taste. "People whose faculties are compromised" seems weak, almost defenseless. Some of these people are defenseless already without us labeling them as such. Historically, they've been treated cruelly, even imprisoned, in parts of the United States. We want to believe that times have changed. But the battle is not over.

Unkind language keeps narrow-minded attitudes alive. Old labels feed old prejudices. In our society, one group or another always draws the short straw, and too often it's the sick, physically and psychologically, who bear the brunt of our linguistic cruelty.

Recently, I let slip with a "you're crazy," and was gently lectured by a friend who lives with bipolar disorder and is active in the mental health community.

"You are perpetuating stereotypes," he said firmly.

"But it was intended to be so benign," I protested. He just looked me in the eye in silence.

Even words that a generation or two ago were acceptable now reveal public prejudice in all its ugliness. New York City's respected Hospital for Special Surgery used to be called the Hospital for the Ruptured and Crippled. Georgia's first state psychiatric facility was the Georgia Lunatic Asylum. You could not make those up.

The name of the Newington Home for Crippled Children in Connecticut, which began its existence as the Newington Home for Incurables, was changed to Connecticut Children's Medical Center more than a generation ago. When I was growing up, "crippled" always seemed a neutral term to me. It seems harsh now. Maybe any word Charles Dickens used is automatically off limits. Tiny Tim needs a name change fast. Ask a guy on a cane about words. Walk a mile in his prescription shoes.

I am legally blind, a measure of how much of my eyesight has been lost to my MS. That is a legal distinction in virtually every state. Legally sightless? There are no degrees of sightlessness.

And then there are "handicapped" and "disabled." I know people who find the word handicapped judgmental. My mother thinks disabled means one cannot function at all. I am agnostic on this one. How about "differently-abled"? That's a popular term now, but it seems silly to me. I think handicaps should be reserved for golfers. Thoughout my 25-year battle with MS, I have spent a lot of time proving to myself that I can do. I am abled. So don't foist your terminology on me. You don't know me. Leave me out of your word box.

"Words are loaded pistols," Jean-Paul Sartre wrote. Rahm Emanuel—and the rest of us—would do well to remember that.

Richard M. Cohen is an Emmy-winning TV news producer and author. His column is published on AARP The Magazine Online every two weeks.