In 1915, the University of Pennsylvania fired economist Scott Nearing. He had supported a law barring child labor, which got him on the bad side of several businessmen on the university’s Board of Trustees. But his biggest transgression was writing an open letter to evangelist Billy Sunday, urging Sunday to rail against “the railroad interests” and other corporate wrongdoers rather than against drunkenness, blasphemy and idolatry.

Penn waited to dismiss Nearing until the summer, when faculty and students had gone on vacation. But they spoke up on his behalf, anyway, especially after Nearing’s case made national news. Students noted that Nearing was a skilled and dedicated teacher. And faculty said that if anybody could be fired for what they said, then nobody was safe.

“I don’t give a damn for Nearing,” declared Lightner Witmer, head of Penn’s psychology department. “He and I disagree on almost everything, but this is my fight. If they can do that to him, they can do it to any of us.”

True enough. And that brings us to Penn law professor Amy Wax, who has recently become the target of an angry, no-holds-barred shaming campaign on my campus. (Full disclosure: although I work at the same institution as Wax and have exchanged emails with her, I have never met her.) Her sin was writing an op-ed that students and faculty members have condemned as racist, the most damaging charge you can level in 2017. It's our own version of blasphemy, rendering the accused into a pariah forever.

But it's also a conversation stopper. And that's very bad news for free discussion, and -- most of all -- for a free university. Just as Lightner Witmer disagreed with Scott Nearing, I think a lot of what Amy Wax says is wrong. But, like Witmer, I also think it's my duty to defend her right to say it, and to plead for a more honest and fair debate about it.

The controversy began Aug. 9, when Wax and a colleague published a column in the Philadelphia Inquirer attributing poverty and other social problems to a breakdown of “bourgeois culture” in the United States since the 1950s. Before then, they wrote, Americans abided by a shared set of social norms around two-parent families, delayed gratification and hard work. But those values have allegedly come apart in the modern era, spawning a catastrophe of idleness, illegitimacy and addiction.

As an historian, I think a lot of these claims are incorrect. They exaggerate the degree of social cohesion in the alleged good old days, which were hardly the happy picnic that Wax imagines. And, most of all, her column understates the many ways that her favored golden era was marred by America’s original sins: racism and sexism. ...