The desire to stamp out disturbing expression is illiberal.

When the censors come, it will be with a smile on their face and unctuous talk about your feelings on their lips. It’s for your own good, they’ll say. Art that takes a stand against hatred will be confused with hate speech. In the spirit of inclusion they’ll exclude. Don’t you know this isn’t safe? They’ll say, as they rip the book out of your hands.

Yanking The Adventures of Huckleberry Finn and To Kill a Mockingbird from school curricula, the Duluth School District in Minnesota is citing the offensive words they contain. This isn’t censorship, quite: The books will still be available in school libraries. They will simply be removed from lists of required reading lists. Nevertheless, the decision is motivated by the censorious impulse, the desire to stamp out this or that disturbing expression.

Nearly all of the fuel for that impulse is these days provided by the protective Left rather than the outraged Right: “We felt that we could still teach the same standards and expectations through other novels that didn’t require students to feel humiliated or marginalized by the use of racial slurs,” the district’s director of curriculum, Michael Cary, told the Bemidji Pioneer.

No specific complaint triggered the decision, Cary added, but for “a number of years” some students have said the racial slurs make them feel uncomfortable. The Duluth school district thinks so little of its students’ ability to cope with texts containing bad words and bad people that it is acting like the genteel pretend prince in Dirty Rotten Scoundrels who requires his mentally deficient brother, Ruprecht, to put a cork on the end of his fork so he won’t stab himself in the eye with it.

The local NAACP chapter has apparently been pressing for the move for years. Its president, Stephan Witherspoon, told the paper that the books are “just hurtful” and use “hurtful language that has oppressed the people for over 200 years.” But the hurtful language is part of the reason the books have the impact they do. The whole point is to transport the reader to the shameful eras of slavery and Jim Crow. To capture the feel of racist oppression in a bygone day is hardly tantamount to continuing to oppress. You might as well argue that those notoriously graphic (and highly instructive) Drivers’ Ed safety videos many of us saw in high school are making students bleed because they depict bleeding. Yet Witherspoon avers that “there are a lot more authors out there with better literature that can do the same thing that does not degrade our people.”

You could argue that To Kill a Mockingbird isn’t a great book — that it’s schematic, or dated, or that its white-savior storyline is patronizing to black readers. A case could be made that today’s young people find Huckleberry Finn boring or unreadable or too far removed from today’s discussions about race. But if you think Mark Twain and Harper Lee are degrading to black people because their characters use racist language, you’re doing literature wrong.

The Duluth-area NAACP finds itself creating an unlikely echo of Jim Crow fans who sought to kill To Kill a Mockingbird because it made white people feel bad about themselves. Denouncing the book as “immoral” and “improper,” the Hanover County School Board in Virginia voted unanimously to remove it from schools in 1966. Lee replied tartly of the board: “What I’ve heard makes me wonder if any of its members can read. Surely it is plain to the simplest intelligence that To Kill a Mockingbird spells out in words of seldom more than two syllables a code of honor and conduct, Christian in its ethic, that is the heritage of all Southerners.”

Fifty years later in the same state, the Accomack County Public Schools Board yanked the same book and Huckleberry Finn from classrooms and libraries after a single individual, the mother of a student, complained, “There is so much racial slurs in there and offensive wording that you can’t get past that, and right now we are a nation divided as it is.” She added that the books amounted to “validating that these words are acceptable.”

Huckleberry Finn has been subject to removal and bowdlerization since the month after it was published: In 1885, the public library in Concord, Mass., banished the book for its “coarse language.” The Brooklyn Public Library booted it from the juvenile section two decades later, and in 1955, a television production for CBS expunged Jim and any mention of slavery from the story. The American Library Association lists it as the 14th-most banned or challenged book in the United States for the decade ending in 2009. In 2011, a new edition was published that removed the racial slurs.

Literature is supposed to help readers accomplish what Atticus Finch famously advised his daughter Scout to do: “You never really understand a person until you consider things from his point of view…until you climb into his skin and walk around in it.” It is doing no favors for young people to quarantine them from books that consider other ages, other mores, other viewpoints — some of which were vile. Learning to grapple with such discomfiting truths is a part of growing up, or used to be. Now the push to turn the whole of literature into a safe space is reinforcing the urge to postpone adulthood indefinitely. As Twain once said, “Censorship is telling a man he can’t have a steak just because a baby can’t chew it.”