A Professor’s Remarks on Sexual Consent Stir Controversy. Now He’s Banned From Campus.

Stephen Kershnar, a philosophy professor, is in academic purgatory.

He is still employed by the State University of New York at Fredonia, but he has not taught or even been allowed on campus for more than a year — fallout from remarks he made in a 2022 podcast about whether it is ever moral for an adult male to have sex with a “willing” 12-year-old girl.

“It’s not obvious to me that this is, in fact, wrong,” he said on the philosophy podcast, as part of a wide-ranging thought experiment about ethics and consent. (As a matter of law, he has said that it should be criminalized.)

His remarks went viral after a right-wing social media account, LibsofTikTok, posted about it.

The president of SUNY Fredonia, Stephen H. Kolison Jr., called the professor’s comments “absolutely abhorrent” and said that Dr. Kershnar was being reassigned to duties that did not require contact with students. He announced an investigation and, Dr. Kershnar said, directed police to search his office and seize his computer.

That was 19 months ago. Dr. Kershnar, a tenured professor who has taught at Fredonia since 1998, is now suing for the right to return to campus, and a hearing in the case began on Wednesday in the Federal District Court for the Western District of New York.

His lawsuit says that university leaders have been “effectuating a social media heckler’s veto, allowing momentary public and political reactions to dictate who may teach at a public university.”

Dr. Kershnar, the lawsuit adds, has never been cited, charged or arrested by any law enforcement agency, aside from traffic infractions.

Free-speech advocates support him, saying that the university’s moves against him are a brazen attack on academic freedom, and they accuse SUNY of invoking safety as a mere pretense.

One of his lawyers, Adam Steinbaugh of the Foundation for Individual Rights and Expression, a free speech group, declined to comment for this article.

In court documents, SUNY Fredonia cites threats and defends its ban as necessary for both Dr. Kershnar’s safety and that of the campus.

“If he were to return,” Brent S. Isaacson, the campus police chief at the time, said in a July court filing, “the public’s disgust would extend to this campus, and we would again be viewed by many members of the public as sympathetic to Kershnar’s views and therefore at risk of violence.”

There were other considerations as well: The university said students and alumni had expressed outrage at the remarks, leading to losses of donations and enrollment.

A university official declined to comment for this article on the pending litigation.

The case reflects continuing tensions over how universities should handle online conflagrations, freewheeling academic discourse and campus safety. Can public universities, which are bound by the First Amendment, restrict professors from campus because of comments they made on a podcast? Should they do so when threats are involved? And what is the marker of an actual threat, anyway?

In January 2022, Dr. Kershnar appeared on a respected philosophy podcast, Brain in a Vat. Each episode follows a format: The guest presents a thought experiment, and the hosts spend the rest of the episode questioning the guest about it. Dr. Kershnar’s thought experiment was explosive.

“Imagine that an adult male wants to have sex with a 12-year-old girl; imagine that she’s a willing participant,” he said. “A very standard, a very widely held view is there’s something deeply wrong about this. And it’s wrong independent of it being criminalized. It’s not obvious to me that is, in fact, wrong. I think this is a mistake. And I think that exploring why it’s a mistake will tell us not only things about adult child sex and statutory rape, but also about fundamental principles of morality.”

Dr. Kershnar has written about this topic in depth for years. In 2017, he published a book entitled “Pedophilia and Adult-Child Sex: A Philosophical Analysis.” An abstract of the book describes it as a look into “the moral status” of such sex, which he said strikes him intuitively as “sick, disgusting and wrong.”

Dr. Kershnar has built his career taking provocative, though rigorously and professionally argued, positions that may horrify or amuse people. Is it morally OK to fake an orgasm? To prefer Asian romantic partners? To not leave a tip? Yes, yes, and no, he has concluded — unless you explicitly tell the server you’re not tipping.

Dr. Kershnar is a “Socratic gadfly” who goes around questioning fundamental assumptions, often quite annoyingly, to try to get at a clearer understanding of morality and why something is or is not wrong, said Justin Weinberg, a philosophy professor at the University of South Carolina and the editor of Daily Nous, a popular philosophy news website.

Controversies surround Dr. Kershnar frequently enough that Dr. Weinberg coined a term for them: “Kershnar Cycles.” Like hurricanes, he wrote, they come in varying strengths, but are usually limited to the academic discipline of philosophy.

After LibsofTikTok posted clips of Dr. Kershnar’s podcast remarks on X, formerly known as Twitter, the university was immediately deluged with demands for action.

An undergraduate at Fredonia started a petition stating that she didn’t feel safe on campus and demanding Dr. Kershnar’s removal. His views, the petition said, are “directly harmful to a community already dealing with instances of sexual assault and struggles with consent.” It received more than 60,000 signatures online.

Alumni threatened to stop giving money. In court documents, the university wrote that the situation with Dr. Kershnar has “unquestionably” caused a loss of donations and a decline in enrollment. The university did not respond to messages seeking comment.

Several members of the New York State Assembly’s committee on higher education wrote to the chancellor of the entire SUNY system, calling for the professor’s “immediate removal,” according to his lawsuit.

More troubling, the university received what officials described as threats of violence. One that was quoted in a court filing said, “On the subject of adult-child relationships, I find a shovel to the head works.” Another said, “I hope parents tar, feather, cut your innards out, and drag your body through town.”

Mr. Isaacson, who was the campus police chief at the time and is a former F.B.I. agent, recommended that Dr. Kershnar remain off campus for a “cooling down” period as police assessed the threat. That recommendation remains in place, the university said in the documents, because protecting the professor would take “an extraordinary and financially prohibitive expansion” of the campus police department.

To critics who said there was no actionable threat of violence, Mr. Isaacson said “Hunters don’t howl,” meaning that an actual violent actor would not telegraph an attack.

Mr. Isaacson recently stepped down, but the new interim police chief agrees with the policy.

Dr. Kershnar’s lawsuit argued that the messages cited by the university did not represent actual threats that justified barring him from campus. And advocates of academic freedom say it is troubling that a vague possibility of violence could bar a professor from campus indefinitely.

“As soon as you accept that principle,” said Mark Oppenheimer, a lawyer in Johannesburg, South Africa, and a co-host of Brain in a Vat, “you can ban any speech you like.”

Philosophy, he said, is especially prone to misunderstanding by the public.

Philosophers “say the wildest stuff and come up with the strangest cases, and any onlooker would go, ‘But you people are all mad,’” Mr. Oppenheimer said. “That’s what happened with Steve.”