Even in a country that has made a pastime of its declamatory public letters, this one seems to stand out. It’s not every day that a list of signatories includes such unlikely comrades as Virginie Despentes—the punk feminist author of King Kong Theory , the Vernon Subutex series and, most recently, Dear Dick Head —and Bernard-Henri Lévy, the dean of Saint-Germain-des-Prés, or what’s left of it. Despentes and Lévy were among the more than 130 writers who on April 16 announced that they were breaking ties with Grasset, a 119-year-old publishing house known for its sober yellow covers and its deep back catalog of classic literature and prestige contemporary titles. Their mass departure has sent tremors across France’s literary and publishing world, which finds itself increasingly under the thumb of the hard-right media mogul Vincent Bolloré, owner of the vast Hachette group, of which Grasset is a flagship subsidiary. “We don’t want our ideas or our work to become his property,” reads the writers’ press release.…