France fancies itself a great literary capital, but attempts to quash a new book that takes on transgender ideology are upending that notion. The socialist deputy mayor of Paris, Emmanuel Grégoire, has in his sights a book called “Transmania” — and wants the posters advertising it pulled from their locations across the French capital. 

It is the latest controversy over what some critics call militant transgender politics, seen most recently in Scotland, where the passage of a new law could make it a criminal offense to “misgender” someone online. The most high-profile critic of that law is author J.K. Rowling.

The authors of “Transmania” are two French feminists, Dora Moutot and Marguerite Stern, who have assailed transgenderism as “an ideology that hinges on propounding as fact that sex does not matter and that what counts is gender, that is to say the societal label.”

The authors have gone even further, calling transgenderism “one of the biggest conceptual heists of the century” — hence the provocative title, “Transmania.” That posters for the book started popping up around Paris was enough for a traditionally left-leaning city hall to intercede. 

It is unlikely that the deputy mayor would have taken his actions without the sanction of the long-serving socialist mayor of Paris, Anne Hidalgo. It was, though, Mr. Grégoire who took to X to say, “Transphobia is a crime. … Paris is not the showcase of this crass hatred. I am going to contact JCDecaux to request the withdrawal of this advertising.”

He did. JCDecaux, a French multinational corporation, is the world’s biggest maker of billboards. It is a name especially familiar to Parisians because it appears at the bottom of virtually every bus-stop billboard and other outdoor advertising spots. On Wednesday, the French newspaper Le Parisien reported that the company had started removing the offending (to some) posters, and news site Marianne reported that the company “apologizes to those who the posters may have offended.”

As to what happens when censorship starts seeping into what is supposedly one of the world’s most enlightened societies, that book has yet to be written. Mr. Grégoire reportedly took exception to the advertising copy that read in part, “When transgender ideology infiltrates all spheres of society.” That for him was more “shocking” than the book itself, which one can only presume is not at the top of his reading list.

The French newspaper Sunday Journal reported that some “Internet users” had complained to city hall about the advertisement, though precisely how many offended Parisians it takes to ruffle the feathers of a French bureaucrat was not clear. Also not clear was how many Parisians the posters did not offend.

If, in any event, transphobia is indeed a crime in France, as the books’ authors maintain, that puts it in the same arena as Scotland, which for the moment is still ground zero in this episode of the culture wars. These tussles are seemingly unending, with Ms. Rowling having won, after a fashion, the latest round at Edinburgh. The iconic author has described transgender women as men in online posts, but police deemed the comments non-criminal.

One of the two authors of the French book, Ms. Stern, challenged the deputy mayor with this riposte on X: “You are not going to have anything banned at all, Emmanuel Grégoire. You will manage your frustration like a grown-up and wait for it to pass.”

Ms. Moutot, her co-author shared a social media post of a French woman who bemoans that “the trans sect is calling on the mayor of Paris to censor posters advertising ‘Transmania.’” That internet user, who labels herself a “non-woke feminist,” added that “Anne Hidalgo rushes to get them taken down; if only she would put as much energy into cleaning Paris and maintaining our streets.”