Philosophy used to be about debating different ideas and seeking answers to hard questions. Now it’s about toeing the line of ‘acceptable opinions’—or facing the consequences.

Often derided as dry and arcane, philosophy has rarely avoided controversy while exploring life’s deepest questions. “Who am I?” “What is real?” “What is the meaning of life?” “How does one seek the good?”

These questions may conjure memories of a rambling, grizzled, absent-minded Philosophy 101 professor, yet they frequently spark fierce debates over which answers can be expressed. Although hailed today, Socrates shuffled off his mortal coil swilling hemlock because his adversaries dubbed any challenges to his day’s prevailing orthodoxies dangerous.

Solomon said, “There is no new thing under the sun.” Yet today, calls for censoring philosophers aren’t coming the “common folk,” but from other so-called philosophers claiming a mantle of “tolerance”—the “social and sexual justice warriors.” Why? Well, some feminist philosophers advanced the common-sense idea that men who think they are women are not really women and that women will get hurt if society pretends otherwise.

As one “tolerant” philosophy student announced this spring, “[any] discourse that does not proceed from this initial assumption—that trans people are the gender they say they are—is oppressive, regressive, and harmful.” If philosophers disagree, their articles should be rejected, and their presentations canceled in the name of stopping “bigotry.” Two philosophical associations then proclaimed, “the right to promote hateful ideas is not covered under the right to free speech.”

Actually, it is. That is the very essence of free speech. As George Orwell observed, “If liberty means anything at all, it means the right to tell people what they do not want to hear.” Hence, the U.S. Supreme Court has ruled that “the proudest boast of our free speech jurisprudence is that we protect the freedom to express the thought that we hate.”

Fortunately, Thomas Jefferson’s idea that universities should be places where we are “not afraid to follow truth wherever it may lead” is still held by at least some philosophers. Twelve of them, from across Europe, North America, and Australia, recently penned a letter defending the right to express “skepticism about the concept of gender identity” and “opposition to replacing biological sex with gender identity in institutional policy making.”

Their letter made it clear that any effort to suppress skepticism endangers the very essence of philosophy:

The proposed measures, such as censuring philosophers who defend these controversial positions or preventing those positions from being advanced at professional conferences and in scholarly journals, violate the fundamental academic commitment to free inquiry. Moreover, the consequent narrowing of discussion would set a dangerous precedent, threatening the ability of philosophers to engage with the issues of the day.

These philosophers acknowledge that “philosophical arguments can lead to pain, anxiety and frustration when they challenge deeply held commitments—whether pertaining to gender identity, religious conviction, political ideology or the rights and moral status of fetuses or nonhuman animals.” After all, one of them, Peter Singer, is infamous for supporting infanticide.

At these moments of disagreement, the solution is more speech, not less. Philosophers should freely debate these types of issues, especially those deemed controversial. The letter from the 12 philosophers continues:

Policy makers and citizens are currently confronting such metaphysical questions about sex and gender as What is a man? What is a lesbian? What makes someone female? Society at large is deliberating over the resolution of conflicting interests in contexts as varied as competitive sports, changing rooms, workplaces and prisons. These discussions are of great importance, and philosophers can make an essential contribution to them, in part through academic debate.

Philosophers can only do so, however, if they aren’t shackled with “narrow constraints on the range of views receiving serious consideration.” Thus, these scholars “reject calls for censuring or deplatforming any of our colleagues on the basis of their philosophical arguments about sex and gender identity, or their social and political advocacy for sex-based rights.”

With this destructive censorship well underway, this perspective is long overdue. Far too many have forgotten (or rejected) the spirit of a quote frequently misattributed to Voltaire, but true nonetheless: “I disapprove of what you say, but I will defend to the death your right to say it.”

In 2017, Dr. Allan Josephson spoke at the Heritage Foundation on how medical professionals should treat children with gender dysphoria. His talk was based on decades of research and clinical experience. For 15 years, Josephson led the University of Louisville’s Division of Child and Adolescent Psychiatry and Psychology, turning the program around. In the three years before his speech, he had earned perfect marks on his annual reviews.

At Heritage, he argued doctors should understand and treat the psychological issues that often cause this confusion before pursuing more radical, aggressive treatments. This sort of reasoned, methodical approach mirrors how medical professionals handle other conditions, let alone those where the treatments might have permanent, negative side-effects.

Yet these few short moments derailed his career. Within weeks of speaking, he was demoted because his remarks angered a few of his colleagues. For the next year, he endured a demeaning, hostile work environment, before the university announced it would not renew his contract, effectively firing him.

Similarly, Dr. Nicholas Meriwether had taught philosophy at Shawnee State University for more than two decades when, in 2018, he answered a male student’s question with a simple, “Yes, sir.” After class, the student demanded to be referred to as a woman. When Meriwether respectfully declined, the student became belligerent, called him an expletive, and promised to get him fired.

Meriwether offered to refer to the student by whatever name he wanted but declined to refer to him as a woman (e.g., “she” or “Ms.”) because that would force him to verbally affirm something he does not believe is true. This did not satisfy the student or the university. Instead, Shawnee State punished Meriwether and warned that he risks “further corrective actions” if he continues to use sex-based terms. Numerous officials have told him this could include immediate firing or suspension without pay.

As the 12 philosophers note, efforts to silence professors like Josephson and Meriwether stifle both academic freedom and freedom of thought. These essential liberties “should be restricted only with the greatest caution, if ever.” Hurt feelings are not enough to silence someone else. As the Supreme Court declared:

Speech is powerful. It can stir people to action, move them to tears of both joy and sorrow, and … inflict great pain. … [W]e cannot react to that pain by punishing the speaker. As a Nation we have chosen a different course—to protect even hurtful speech on public issues to ensure that we do not stifle public debate.

Philosophers must remain free to be philosophers. Psychiatrists must remain free to explore the best treatments for patients. Most critically, all Americans must remain free to express their views without having to worry about needless government scrutiny or jeopardizing their livelihoods.