Erika Christakis, associate master of one of Yale University's residential colleges, has decided to stop teaching at the university, in part because of the continuing controversy over an email message she sent about Halloween costumes.

Some students have been pushing for her ouster from her position in the residential college and from teaching, but she is not leaving the position at the residential college. To some observers, however, it is more concerning that someone who was teaching at a college (off the tenure track) has felt compelled to stop doing so because of reactions to something she wrote.

Christakis, who did not respond to a request for comment from Inside Higher Ed, wrote in an email to The Washington Post that “I have great respect and affection for my students, but I worry that the current climate at Yale is not, in my view, conducive to the civil dialogue and open inquiry required to solve our urgent societal problems.”

She became a source of controversy just before Halloween. At that time, Yale, like many colleges, was advising students on the types of costumes and parties that might offend others. Christakis sent out an email that said, in part: “Even if we could agree on how to avoid offense -- and I’ll note that no one around campus seems overly concerned about the offense taken by religiously conservative folks to skin-revealing costumes -- I wonder, and I am not trying to be provocative: Is there no room anymore for a child or young person to be a little bit obnoxious … a little bit inappropriate or provocative or, yes, offensive?

“American universities were once a safe space not only for maturation but also for a certain regressive, or even transgressive, experience; increasingly, it seems, they have become places of censure and prohibition. And the censure and prohibition come from above, not from yourselves! Are we all okay with this transfer of power? Have we lost faith in young people's capacity -- in your capacity -- to exercise self-censure, through social norming, and also in your capacity to ignore or reject things that trouble you?”

Many minority students immediately called for her ouster. Further, in an incident that attracted widespread attention, a student shouted repeated expletives at her husband, Nicholas Christakis, a professor at Yale and the master of the residential college where she works, when he tried to discuss the email and related issues.

Yale has taken no action against either Christakis, despite the demands that it do so, and officials have stated that they will not do so. But some professors believe that a more forceful defense of them should have been offered, and that people shouldn't stand by while she is called a racist. Last week dozens of faculty members issued an open letter expressing public support for Erika and Nicholas Christakis and calling for an end to personal attacks on them (regardless of what one thinks of the ideas she expressed in the email).

By most accounts Erika Christakis, an expert on early childhood, was an outstanding teacher, and students have in the past praised her courses. As word of her decision to stop teaching at Yale spread, she received support on social media from many, including people who have been critical of the recent student protest movement.

Douglas Stone, a professor of physics at Yale who organized last week's open letter, said via email that the resignation of Christakis from teaching was a cause for great concern. "This is a very disturbing development," he said. "Last year Erika Christakis's classes were shopped by over 300 students and many who wished to take them were turned away. She has received truly exceptional teaching evaluations. This year she planned to teach additional sections to handle the demand. The attacks she has received, not just on her ideas, but on her character and integrity, have led to the decision not to teach …. Those who mounted the campaign against her have significantly reduced educational choice for all Yale undergrads."

Stone added that there was "real reason" to worry about academic freedom at Yale. "Several undergraduates have told me in conversation or by email that they feel scared to express their honest opinions relating to current events that have raised racial issues because of the likely negative and aggressive response of peers," he said. "In some cases these were nonwhite students, who care deeply about racism and sexism, but nonetheless support the sentiments expressed in our letter of support for the Christakises. They have also claimed that their view is probably held by the majority of undergrads; even if that is not true (and I don't know how one can decide at the moment), it suggests that there are substantial barriers to free exchange of views on these issues at Yale in the current climate."

Among those expressing concern about the Christakis announcement was Corey Robin, a professor of political science at Brooklyn College and the Graduate Center of the City University of New York. Robin is a prominent voice of the academic left on Twitter.

He said that he wouldn't have been concerned if Christakis had quit or been removed from her position in a residential college, since that is primarily an administrative role.

More issues are raised, Robin wrote on Twitter, by someone in a teaching position who feels unable to teach because of political pressure over her ideas. "All the evidence suggests she is an excellent, popular teacher; the only reason she is stepping down is because of political views she has expressed in the public sphere," Robin wrote.

He added: "I am not a free speech absolutist; I think there are grounds, highly circumscribed and carefully drawn, when someone's speech may justify them being removed from a teaching position. I don't think Christakis's speech rises to that level. While I know full well that employment sanctions are used primarily against the left -- and refuse to join the equivalence brigade which thinks that right and left are equally penalized by these sanctions or that offensive speech from the right is the same as provocative speech from the left, and that you can't tell the difference between the two -- I also know that there is no way the left can escape unharmed from this kind of employment sanctions regime, that we will never be able to win free speech fights if we are perceived as defenders only of speech from our side."