Ninety years ago, Supreme Court Justice Louis Brandeis proclaimed that the best solution to offensive speech was “more speech, not enforced silence.” This philosophy undergirds the First Amendment: We constrain our government from curtailing speech by relying on the marketplace of ideas to do so instead.

Clearly, Brandeis never tried Twitter. His formulation did not account for the relentless counter-speech enabled by ­social media or its potential censorious effect.

We are living in a counter-speech boom. In Oakland, Calif., the hassling of African Americans at a cookout prompted a festive “barbecuing while black” demonstration. And when New York lawyer ­Aaron Schlossberg was caught on video threatening to call immigration enforcement on deli employees speaking Spanish, the backlash was fierce — more than 4,000 critical reviews of his law firm on Yelp and protests outside his apartment including a full mariachi band.

Meanwhile, when a UCLA panel discussion on indigenous peoples left out Palestinians, protesters disrupted the talk with drumming and chanting until security officers intervened. Elsewhere, controversial talks have been met with marchers, pamphleteers, hecklers and occasional violent protests — almost always captured on video to fuel a potent online afterlife. 

Counter-speech is among the healthier responses to this polarized political moment. The White House’s apparent indifference to concerns of racism, sexism and immigrants’ rights has motivated citizens to speak up. Shaming campaigns can advance equality by raising the social cost of denigrating others. After comedian Roseanne Barr posted a blatantly racist tweet, ABC acted preemptively to cancel her show as public outrage mounted. Whereas the burden of counter-speech historically has fallen on members of targeted groups, vocal allies can offer support. At their best, such interchanges can culminate in deeper shared understandings.

But counter-speech can also, paradoxically, suppress speech and ideas. When protests shut down a lecture or panel discussion, listeners hear only those who shout loudest. Online fusillades intimidate not only their targets but also others who dare to raise similar questions.

Amid the onslaught against Schlossberg, journalist Julia Ioffe questioned whether critics had overreached, tweeting, “I find the mob unsettling, even if it’s a mob whose motives I agree with.” After being flooded with more than 8,500 comments, mostly critical, Ioffe thanked the mob for proving her point.

Furious counter-speech can chill even strong institutions. When the Guggenheim Museum was targeted by a mass petition protesting Chinese artworks that featured and depicted live animals, it quickly pulled the pieces, citing safety fears. After harsh criticism, the White House Correspondents’ Association renounced a provocative performance at its annual dinner by comedian Michelle Wolf, the turnabout itself prompting a new wave of opprobrium.

The censorious potential of cacophonous counter-speech demands that free-speech advocates consider not just the letter but also the spirit of Brandeis’s maxim. Some parameters are obvious. Violence and scare tactics are clearly out of bounds. Physical intimidation — including throngs of unruly protesters in a confined space or constraints on a speaker’s physical movement — should also be off-limits. Online menacing — such as publicly revealing someone’s address or phone number as an invitation to stalking or harassment — is likewise beyond the pale.

While it is legitimate to call on a speaker to stand down, insistence that government officials quash or punish speech veers into censorship. You can firmly reject a speaker’s message without demanding that he or she suffer for it. Even if the target deserves no sympathy, when social ostracization becomes demonization and dehumanization, it debases our discourse writ large.

This doesn’t mean all counter-speech must be polite or even civil. Some disruption — such as a modest delay to protest a campus talk or a series of provocative queries during a discussion period — can be a powerful way to make a point. Some of the most forceful forms of counter-speech — mass marches, walkouts, barbecues and mariachi performances — are seen and heard without stifling others.

Digital discourse affords us the collective power to justifiably inhibit speakers from voicing noxious views. But it also allows us to silence countless others who may withhold original ideas or provocative perspectives because they fear toxic, virulent blowback.

With that power comes a responsibility to think hard about what voices and viewpoints to stifle. It is tempting to extinguish anything that affronts us. But doing so would legitimize the idea that mobs can and should exert an authority we have always denied our elected government: namely, the power to decide what ideas live and die in the public sphere.

When does counter-speech risk crossing into censorship? A simple question may help: Recognizing that disparities of power can inflect the potency of speech, would the nature and ferocity of protest against views with which you disagree be acceptable if levied against opinions with which you agree? If the answer is no, consider whether the reaction is justifiable and how it might chill other speech.

Rowdy counter-speech can feel empowering, but Brandeis championed it not to gratify the speaker but to advance the quest for truth. Ultimately, the purpose of counter-speech should not be to exact retribution or to humiliate, but rather to persuade.

Read more: