There are few pronouncements that garner more enthusiastic applause than “I’m not politically correct.” There are also few that are more meaningless. A recent study, published in The Atlantic, reveals that “80 percent of Americans believe political correctness is a problem.” Widespread antipathy for an idea is hardly a surprise when that idea has no public defenders. There are certainly various leftists who advocate politically correct regulations of speech, but not once have I ever heard anyone embrace or self-apply the term. To everyone except perhaps those who occupy fringe territories of social thought, “political correctness” is synonymous with dishonesty and fragility.

Making the study even more dubious is that political correctness is a term without a definition, or at least a definition on which most people can agree. Donald Trump parlayed his opposition to political correctness into the presidency. A leading liberal columnist, Jonathan Chait, who is also a vociferous critic of Trump, routinely decries “political correctness on college campuses.” It is a safe bet that P.C. means something different to Donald “Good People on Both Sides” Trump than to Chait, who authored a book extolling the greatness of the Obama legacy.

Laboring under the fog of semantic confusion means that whenever Americans discuss, and even ridicule, political correctness, they risk degrading public discourse. It is critical for the left to define political correctness, because they are most closely associated with it. But it is equally important for the right, because to permit any violation of political decorum under an umbrella of resistance to the “P.C. police” means demolishing healthy limits on public behavior. This is how elemental social norms that help ensure kindness, civility, and basic respect get erased.

So after years of linguistic abuse, what exactly does political correctness mean?

It’s easy to find numerous examples of conservatives criticizing the “snowflake generation.” In my home state, a group of petulant philistines recently insisted on the removal of a Thomas Hart Benton mural from Indiana University, because, as part of his depiction of that state’s history, the great painter included an image from a Ku Klux Klan rally. In 2013, many feminists demanded that then-President Barack Obama apologize for complimenting, in a jocular tone, the physical beauty of Kamala Harris shortly after lauding her professional achievements and progressive principles.

If artistic representation of the dark side of a state’s history and respectful appreciation of a woman’s appearance are suddenly taboo, then it is certainly necessary to destroy political correctness. But what happens when the cruel and the vulgar confuse political correctness with fundamental decency?

My wife works with adults who have developmental disabilities, helping them secure employment and group home placement (if necessary) and navigate the morass of social services. There is not one client or family member my wife has met who approves of the label “retard” for someone with intellectual disabilities, let alone as a pejorative for a person guilty of foolish behavior. The word has a hard edge and is universally hurtful, even though several decades ago it was in common, and often official, use.

Ann Coulter has twice employed “retard” against politicians she feels are unintelligent. The first, in reference to President Obama, prompted an invite to the Special Olympics so that she might have a “change of heart” about her casual insult. (Coulter did not respond to the invitation.)

During the 2016 campaign, Donald Trump mocked the physical disability of Serge Kovaleski, a New York Times journalist who disputed one of Trump’s many misleading statements. Eighty-three percent of voters claimed that Trump’s cruel and cartoonish imitation of Kovaleski “bothered them,” but the current president never apologized, seemingly able to assimilate the mean-spirited display into his politically incorrect style.

If affirmation of the full humanity of the disabled and avoidance of terms and gestures that degrade them is now part of political correctness, then the idea is worthy of protection. Some might argue that kindness towards those with intellectual disabilities and physical handicaps is merely a matter of decency and should remain apolitical. I would like to agree, but the Trump episode demonstrates that politicization of anything—no matter how juvenile, crude, or demeaning—is possible under the banner of anti-P.C.

The crux of the question is what a shared culture determines to be a healthy and beneficial amount of sensitivity in political debate and social relations. Conservatives are correct to warn of the dangers that face an overly sensitive society. Nineteen-year-olds who cannot bear the sight of the Ku Klux Klan in a painting are not prepared for adulthood. The very notion of a “safe space” is ahistorical—anyone with any knowledge of the human story understands that the world is one giant unsafe space. Indiana University, which did not remove the mural but no longer schedules courses in the lecture hall where it is located, violated an essential principle of its mission as an educational institution by electing to coddle rather than strengthen its students.

The antidote to excessive sensitivity, however, is not coldhearted insensitivity. Speaking sensitively about people living with disabilities is necessary, fair, and, to put it as simply as possible, the right thing to do.

Not every advocate of what appears to be political correctness is acting in bad faith. No matter the absurdity of some of the left’s demands, there is a substantive conversation going on over what constitutes publicly permissible speech, not as a matter of the law, but ethics. There are still Americans who can recall when the “n-word” was acceptable in polite conversation, along with other ethnic slurs. The unwritten prohibition on racial epithets improves American culture, because it increases the likelihood of coexistence and provides incentives for treating one’s neighbors and fellow citizens with respect.

Few on the right or the left ever acknowledge the hazy area of moderation between excessive sensitivity and insensitivity. Rather than glibly throwing around accusations like “snowflake” and “bigot,” thoughtful progressives and conservatives should continue negotiating what forms of speech should be culturally approved and disapproved.

There is no single set of rules that can solve the problem. Progress of the apolitical kind will require case-by-case and individual-by-individual treatment. But what’s needed most is liberation from what has become the most suffocating form of political correctness—robotic adherence to tribal lines of partisanship.

David Masciotra is the author of four books, including Mellencamp: American Troubadour (University Press of Kentucky) and Barack Obama: Invisible Man (Eyewear Publishing).