Jonathan Zimmerman:

A few years ago, I invited Mary Beth Tinker to meet with my undergraduate class on the history of American education. Tinker herself is an important figure in that history, because she was one of the students who wore black armbands to school in Des Moines, Iowa, in 1965 to protest America’s involvement in the Vietnam War. Sent home as a punishment, she sued her school district on free-speech grounds. Tinker v. Des Moines made its way to the Supreme Court, which ruled in her favor in 1969. In a ringing decision, the Court declared that neither students nor teachers need to “shed their constitutional rights to freedom of speech or expression at the schoolhouse gate.”

My students loved Tinker’s story, and who doesn’t? Adorable seventh grader confronts Big Bad Authority. Adorable seventh grader wins. Cut to the credits.

But when our class discussion turned to the present, the mood changed. Students insisted that schools and universities should prohibit hate speech, which hurts innocent people. Mary Beth Tinker was fighting the good fight, against the war in Vietnam. But racists and sexists and homophobes and transphobes are different, my students said. They cause harm, offense, and even trauma in their victims. We need to shut them down.

Tinker wasn’t having it. At her middle school in Des Moines, she said, there were students who had fathers, uncles, and brothers who were fighting in Southeast Asia. Don’t you think they were offended and hurt by a snot-nosed kid whose armband suggested that their loved ones were risking their lives for a lie?

Of course they were. Speech hurts, which is why censors across time have tried to stamp it out. So if you’re going to bar speech that hurts someone, well, forget about Tinker’s armband. Forget about free speech, period.

My students took this in, and then they tried another tack. Wasn’t free speech really just a tool of the powerful? That’s why white men like it so much, of course. It lets them have their say while it harms (there’s that word again) people with less status and influence in society.

Mary Beth Tinker wasn’t having that, either. In 1965, she told the class, she was a 13-year-old girl. Free speech was the only power she had! Take that away, and she would have nothing at all.

Welcome, folks, to the world of competing, irreconcilable goods. Also a reminder of why the harm principle will never solve these problems: an unconstrained use of the harm principle can silence anything and everything, because a claim to internal psychological harm can never be assessed independently.