President Trump speaks at an event on Friday in Sioux Falls, S.D. (Susan Walsh/Associated Press)

On Wednesday, the New York Times published an unusual anonymous op-ed from a senior official in the Trump administration. This has sparked a wave of commentary, trying to identify the figure, reacting to its explosive contents and assessing the legitimacy of anonymous commentary and disclosure.

President Trump’s conclusion: “TREASON?” White House press secretary Sarah Huckabee Sanders attacked the Times for publishing the “pathetic, reckless and selfish op-ed,” and described its author as a “coward.” Even the president’s opponents attacked this author, calling for him or her to “Speak in your own name.”

But anonymous publication has been an essential feature of American democracy since its beginning. It has long allowed vulnerable voices to participate in public politics and speak truth to power. Indeed, anonymous debate was at the center of the revolutionary politics that led to American independence, the U.S. Constitution and the Bill of Rights, which enshrined the press freedoms that continue to protect anonymous speech today.

In the late 18th century, pseudonyms and anonymous sources filled the pages of newspapers. In fact, some of the most prominent Founding Fathers regularly used the shield of pseudonyms in political essays during the era of the American Revolution: Thomas Paine, John Dickinson, Alexander Hamilton, Arthur Lee, John Jay, Benjamin Franklin, Thomas Jefferson and James Madison. Influential texts such as “Common Sense,” the Federalist essays and the “Letters from a Farmer in Pennsylvania” essays were all published without an author's byline.

In many of these cases, well-known, elite authors expected that their audience would be able to identify them. Early American cities were, after all, small towns by today’s standards. Indeed, shortly before he began to write the Federalist essays, Hamilton wrote a controversial essay under a pseudonym to “avoid the appearance of ostentation,” an ally explained privately. He feared, according to this friend, that a signed essay would make it seem as if he was seeking fame and publicity — a crucial sin for an early modern politician.

As Madison, Hamilton and Jay published the Federalist essays, they protected their identities closely, using the pseudonym “Publius” and denying their involvement to all but their closest associates. Yet some contemporaries quickly and accurately guessed their identities.

Their use of a pseudonym was probably not intended to avoid detection or retribution. Rather, they probably hoped that their pseudonym would focus their readers’ attention on their arguments rather than their personalities. Moreover, by removing themselves from the conversation, they sought to embody the broader public.

But the significance of anonymity goes deeper. Most unsigned newspaper essays and pamphlets, after all, were not written by “Founding” figures. Most of them were truly anonymous — both for their contemporary readers and for historians today. They needed to be anonymous, because their authors feared what might happen to them if they used their real names. As one author noted in 1764, if essayists were forced to print their names, “The Cause of Liberty would often be left to suffer” because they would have made themselves vulnerable to the “Clamour of Party, or the Resentment of Power.”

This applied to many of those who argued against the ratification of the Constitution in 1787 and 1788 and against Publius. Despite pressure to reveal their names, they used pseudonyms to protect themselves. In that polarized climate, more than one writer suggested that it was “unsafe to be known to oppose” the proposed Constitution, so true anonymity was necessary to participate in politics.

Anonymous publication allowed anti-ratification writers to challenge a popular view of the Constitution, and ultimately played an important role in the creation of the Bill of Rights. The First Amendment, which protects anonymous speech today, may not exist in its current form if not for these anonymous anti-ratification writers.

Of course, this practice could also be used to smear and gossip about political rivals. That is why, as one writer signing his name J. Bracken explained in a 1775 newspaper, essays containing “personal or party abuse … [anything] illiberal or injurious to the character of any person” were expected to be published with their authors’ names. And yet, as historian Joanne Freeman has shown, unsigned pamphlets were a sneaky but dangerous way of impugning another gentleman’s reputation. If the victim realized who was behind the rumor, however, the parties might engage in open conflict, or even a duel.

Just as it was in the 18th century, anonymity can be used today to spread division and falsehoods, as Russian agents did during the 2016 U.S. presidential election with anonymous or pseudonymous social media accounts. By shielding an author from consequence, anonymity can allow him or her to act illegally or in bad faith.

And this may be how many critics feel about the New York Times op-ed. The White House’s response echoes that of 18th-century writers who denounced unsigned essays as “vile slander” and “anonymous scurrility.” But Trump and his aides have only themselves to thank for the author’s need to write anonymously.

Trump has repeatedly attacked the free flow of information and First Amendment rights, using the bully pulpit to demonize, embarrass and punish those who stand up to him. As a result, this is a moment — as it was for those who opposed ratification of the Constitution — when the possibility of anonymity is most valuable. When power is aligned against truth, truth must have a safe harbor from power.

When used irresponsibly, anonymity can harm the institutions and the deliberative processes that make democracy possible. It is easier to exaggerate or engage in ad hominem attacks when one is not facing consequences. But those who would criticize anonymous speech must also recognize that anonymity has been an essential, and often productive, feature of American democratic politics since its beginning.