Dangerous Liaisons has two prefaces, both presumably written by Laclos himself, a "Publisher's Note" (Avertissement de L'Editeur) and an "Editor's Preface" (Préface du Rédacteur).
The "Publisher's Note" says that he has good reason to believe, contrary to what the "Editor's Preface" will say, that the letters following his note are fiction. He maintains that it is impossible to believe that men and women as evil as those portrayed in these letters could exist in so enlightened an age as his own. He therefore urges the reader to take the exploits of the letter- writers with a grain of salt, especially since, "...we never see girls nowadays who have dowries of sixty thousand livres taking the veil, anymore than we see young and pretty married women dying of grief" ("...nous ne voyons point aujourd'hui de Demoiselle, avec soixante mille livres de rente, se faire Religieuse, ni de Présidente, jeune et jolie, mourir de chagrin"). This is witty reference to the tragic ending of the novel.
The "Editor's Preface" is a long explanation of how he received, decided to publish, and organized letters from an actual correspondence in an actual society. The length of the preface results from the "Editor's Preface" tendency to apologize profusely and frequently for the possibly offensive nature of what is contained in these letters. He finds, however, that the usefulness of the correspondence to teach people how to stay out of trouble outweighs any tendency it might have had to get them into trouble. If it did not, he promises the public that he would not have published either the book or the preface itself.
At first glance, these prefaces seem intended to defray some of the shock and outrage that would naturally result in French society from the publication of Dangerous Liaisons. But, through their anticipation of the reader's reaction, the prefaces ingeniously poke fun at what will certainly be an extreme response to a set of fictional letters. The tone of the prefaces, fluctuating between earnestness and sarcasm, anticipates the alternately condescending and flattering terms of the letters exchanged by the Vicomte de Valmont and the Marquise de Merteuil in the body of the novel.