On campuses across the country, hostility toward unpopular ideas has become so irrational that many students, and some faculty members, now openly oppose freedom of speech. The hypersensitive consider the mere discussion of the topic of censorship to be potentially traumatic. Those who try to protect academic freedom and the ability of the academy to discuss the world as it is are swimming against the current. In such an atmosphere, liberal-arts education can’t survive.

Consider what happened after Smith College held a panel for alumnae titled “Challenging the Ideological Echo Chamber: Free Speech, Civil Discourse and the Liberal Arts.” Moderated by Smith President Kathleen McCartney in late September, the panel was an apparent effort to address the intolerance of diverse opinions that prevails on many campuses.

One panelist was Smith alumna Wendy Kaminer—an author, lawyer, social critic, feminist, First Amendment near-absolutist and former board member of the American Civil Liberties Union. She delivered precisely the spirited challenge to the echo chamber that the panel’s title seemed to invite. But Ms. Kaminer emerged from the discussion of free speech labeled a racist—for defending free speech.

The panel started innocuously enough with Ms. Kaminer criticizing the proliferation of campus speech codes that restrict supposedly offensive language. She urged the audience to defend the free exchange of ideas over parochial notions of “civility.” In response to a question about teaching materials that contain “hate speech,” she raised the example of Mark Twain’s “The Adventures of Huckleberry Finn,” arguing that students should take it as a whole. The student member of the panel, Jaime Estrada, resisted that notion, saying, “But it has the n-word, and some people are sensitive to that.”

Ms. Kaminer responded: “Well let’s talk about n-words. Let’s talk about the growing lexicon of words that can only be known by their initials. I mean, when I say, ‘n-word’ or when Jaime says ‘n-word,’ what word do you all hear in your head? You hear the word . . . ”