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You can cause a great deal of fuss by stating some obvious truths about someone’s bad behavior, and then affirming principles that a sixth grader can understand.

My friend Bryan McGrath and I learned that when we circulated a letter in February 2016 (published in March) denouncing then–presidential candidate Donald Trump. We got 122 signatories and a lot of attention. This happened again in August when a similar letter (which I also signed) from 50 former senior Republican officials hit the streets. We merely noted that Trump had expressed a range of bigoted, dangerous, and vile opinions and was a human being of wretched character. The principle was that someone holding those views and displaying such qualities was unfit to serve as president of the United States. In a different time and place, this would have been considered self-evident.

Last week, Harper’s published a “Letter on Justice and Open Debate,” signed by 153 journalists, writers, and academics, including some of my colleagues at The Atlantic. It describes a plain fact: the spread of intolerance in the public square. “While we have come to expect this on the radical right, censoriousness is also spreading more widely in our culture: an intolerance of opposing views, a vogue for public shaming and ostracism, and the tendency to dissolve complex policy issues in a blinding moral certainty.” And it affirms a basic principle: that the “free exchange of information and ideas,” including unpopular ones, presumably, is “the lifeblood of a liberal society.”

Similar things followed for the Harper’s letter signers as had happened to us: snorts of derision about posturing intellectuals; accusations of betraying one’s own admittedly imperfect team in the face of a much worse alternative; tweet storms from angry persons. There were some squeaks of dismay when a few shaky signatories realized that a hastily written email of agreement had brought down the wrath of Twitter trolls. A couple (including, in the Harper’s case, a contributing writer to The New York Times) cringed at their own temerity in agreeing with people who should be disapproved of. There were a couple of publicly articulated recantations in the name of orthodoxies transgressed. And at the end, as with the Trump letters, it seemed that nothing much had changed.

But not really. In bad times—and these are, in some respects, very bad times—speaking the truth, laying down a marker, drawing a line are valuable in ways that you can never fully anticipate. Intolerance of diverging points of view—an insistence on the primacy of safety and comfort at the expense of inquiry, growth, and rational inquiry—is a powerful and deeply dangerous force. Somebody has to fight it, and a lot of the muscle has to come from those on the side of the political spectrum opposite mine. The modicum of spine that it takes to speak the truth and lose a few friends (usually in the debased, thoroughly Washington sense of that word) is valuable. It is also pretty rare.

In 2016, conservatives in general, and Republicans in particular, went down a rat hole of grievance, nationalism, bigotry, and outrageous incompetence. If the job of a conservative is, as William F. Buckley Jr. once put it, to stand athwart the course of history and yell “Stop!,” those who signed the 2016 letters did their job. They were taking a stand that might much later inspire others. At least they chose to attest to the fundamental fact that two plus two equals four, whether we like it or not. And that commitment to a kind of moral basic arithmetic is, as Albert Camus told us, at the heart of what moral clarity, and with it, moral courage, are all about.

One prominent liberal intellectual wrote to me on several occasions after the first Never Trump letter wondering whether they would have the courage to write and sign the same kind of thing when the threat came from their side. After the obligatory pish-push—it did not take a whole lot of courage for me as a tenured professor, a member of one of America’s most liberal collection of institutions, the university, to denounce Trump—I informed my friend that their time might come.

It did, and I am glad to say it was met, which is why we should welcome the Harper’s letter. Critics described some past statements by certain signatories as bigoted, faulted the other signatories for giving them support, and argued that the letter itself was more concerned with suppressing criticism than correcting injustice. Willfully or not, they missed the point. The principles the letter affirmed are indeed the lifeblood of a free society. Those who signed it deserve credit for insisting on that point, and some measure of encouragement and support from the rest of us. If courage seems too strong a characterization, then at least recognize that, in today’s environment, they are showing some gumption in fulfilling the intellectual’s duty to express truth as clearly as he or she can to people who do not wish to hear it.

No, nobody is going take away J. K. Rowling’s millions, or strip Todd Gitlin of tenure. But the truth is that the penalties for getting out of harmony with the zeitgeist are a lot tougher on the left than on the right these days. The Harper’s letter includes signatories who have indeed found themselves defamed and excoriated in ways far worse than their colleagues on the right. Maybe at Liberty University the threats to free thought come from the right; at most universities and in most newsrooms, they emerge from the other side of the spectrum.

Courage in the public square is very rarely about unearthing an epic wrong and seeking to right it—finding a pit of dastardliness and uncovering it for all to see. It is never about making those on your own side feel more smugly confident about the rightness of their views. It is, rather, about speaking the hard truths that, as my university’s motto has it, will make you free. And it is usually about speaking a pretty obvious but awkward truth to your own side, and reaffirming inconvenient principles that in less fevered times would meet unquestioning acceptance.

It has been a bad time on the right, and will stay so for some time. The poisons that Trump-style obscurantism, ethno-nationalism, and cruelty have brought to the surface will not swiftly disperse. The Republican Party may indeed be ruined beyond repair as even that once unshakeable optimist Bill Kristol has ruefully acknowledged. But it is also very bad on the left. Cancel culture is real, and it is not going away, and that makes the Harper’s letter both honorable and useful.

The lesson the Never Trumpers can share is that after taking your stand, you can expect either sneering hostility or irrelevance for quite some time. At the end of it, you may not get a great deal of gratitude either, certainly not from your own side, and possibly not from those on the other. When the tide turns, they may prefer to recall your previous thought sins rather than your moments of integrity; more likely, they will prefer to pretend the whole unpleasantness never happened. And you may very well find yourself alone, adrift from associations that had been part of your life. For a small minority, it could cost you a job.

It’s still not the same thing as going to jail, getting tarred and feathered, being force-fed castor oil, or getting beaten up. All, or almost all, of the signatories of the Harper’s letter will be fine from a financial and even social point of view. But to remain true to themselves, they are going to have to continue administering doses of truth to their own side, and take the abuse that comes with it.

Good for those signers. Aside from a few craven recusants, who will now forgo both respect and self-respect, they will be glad they did it, and should be. And they will find, as I did, that once you have emancipated yourself from some of your previous affiliations and orthodoxies, you can think more freely and creatively than before. Which, after all, is what the life of the mind is all about.

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