As covid-19 continues to ravage Americans, there has been a growing call from some quarters for a national mask mandate. The former head of the Food and Drug Administration, Scott Gottlieb, for example, has called for “a limited and temporary national mask mandate” of two months. Yet in an interview last week, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, offered a striking response — given his views on the importance of masks — to a question about such a mandate. Given that masks significantly slow the spread of the coronavirus, he was asked, wouldn’t it make sense for president-elect Joe Biden to require that all Americans residents wear one, under penalty of law?

Fauci’s answer was refreshingly nuanced. The goal is indeed to get every American to wear a mask, he acknowledged — as that would slow the spread of the pandemic more than anything else yet tried by federal, state and local governments. But there is reason to “shy away from” fully endorsing the idea, he added, because  “things that come from the national level down generally engender a bit of pushback from an already reluctant populace that doesn’t like to be told what to do … you might wind up having the countereffect of people pushing back even more.”

For Fauci, it is one thing to acknowledge the obvious necessity of mask-wearing; it is quite another to get people to conform to this necessity. This is an age-old problem that governments face — one that Fauci might have encountered as a classics major at Holy Cross College, in Plato’s “Laws.” In that workthe final, and among the least-frequently read, of his celebrated dialogues Plato’s interlocutors discuss exactly the problem Fauci alludes to in his interview: How do states get citizens to follow laws that are clearly for their own benefit?

Laws by themselves can do no good if they are rejected by the people, Plato suggests. That’s not an excuse for abandoning the attempt to pass useful laws, but rather an argument that they must be preceded by persuasion. Even if Biden could pass a mandate with a stroke of a pen (legally dubious) — or with the help of a likely Republican Senate (politically dubious) — such efforts would come to nothing if people’s minds aren’t changed on the fundamental question concerning the public health benefits of masks.

In the “Laws,” the main character, the “Athenian Stranger,” compares this political challenge to a parallel one in medicine: How does a physician get a patient to take a prescription? In the case of enslaved people, he remarks, it is a simple matter: the doctor simply prescribes and the patient obeys. Malady cured. But the task is considerably more complex for free and democratic citizens, such as existed in Athens then and in the United States today. The physician tending to democratic citizens “teaches the one who is sick.” Plato’s Stranger continues, “He doesn’t give orders until he has in some sense persuaded; when he has on each occasion tamed the sick person with persuasion, he attempts to succeed in leading him back to health.”

Without this act of nudging people toward grasping what is in their interest, the cure — whether involving medicine, surgery, diet or rest — is latently effective but effectually impotent.

The implications for public policy are clear. One can imagine all kinds of laws, edicts and other official measures aimed at improving citizens’ health, safety and welfare. Yet unless the citizens can be expected to obey those measures, they are for naught. Worse, strictures that aren’t obeyed foster an environment in which the laws become mere suggestions — or even nuisances that foster a habit of ignoring laws generally. Thus, as Plato’s Stranger advises, lawmakers must employ reason and all other measures at their disposal to effect this change of heart. Only once they are persuaded of the measures’ wisdom will they consent to obey the laws.

In the interview this month, Fauci expressed some faith that a mix of taking in news reports and personal experience might turn mask skeptics around: “Hopefully we can convince people when they see what is going on in the country,” he said. (Though he also lamented the effect of “fake news.”) He did not stress as much as he might have the maddeningly inconsistent statements by public officials:  While some states have imposed mask mandates, and some governors have been outspoken about the need for face coverings, others have chosen to cast the issue as a matter of personal preference. And, of course, the president has largely shunned masks and even mocked others for wearing them. So the premise for good lawmaking has not been met. As Fauci observes, “people still insist that something that’s staring you right in the face is not real.”

That points the way to Biden’s true task. Persuasion can take many forms — appeals to peer-reviewed scientific studies, emotional appeals to those who have suffered family losses, narratives about individual cases. But the bottom line to is get citizens to understand and accept that these measures are for their own good. Without that step, we will likely continue along the deadly path we have thus far charted. (Biden may also have to work his persuasive powers on governors, who can implement state-level mandates.) A skeptical citizenry will create even more problems when a vaccine arrives: A substantial portion of Americans — enough to defeat the goal of herd immunity — have said they will refuse to take it. Clearly, Plato’s physician will continue speaking to us for the duration of this interminable calamity.