Appendix to a proposed English edition of Voltaire’s Honnêtetés littéraires, this interdisciplinary paper offers a critical translation of one of the apocryphal letters of Madame de Maintenon — the morganatic wife of Louis XIV — which Voltaire informs us were forged by Laurent Angliviel de La Beaumelle. An introduction and notes realign the supposititious letter in the dual context of a deconstruction of the historical mariage polémique of the competing writers and a rereading of Derrida’s Donner le temps 1. la fausse monnaie. It posits a tradition of ironic discourses of authenticity in modern French historiography, implying a simultaneous inception and rupture at this arbitrary point of the key Enlightenment dichotomy of fiction and history: one that is analogous to Derrida’s conflation of the comic and the philosophical in response to the transactions of time. The episode is revealed to be the recurring central theme in an unresolvable and unattributable inheritance of ludic fabrication in French literary historiography: a tradition whose most recent interpolation has been the duping of Bernard-Henry Lévy by the inventors of the philosopher Jean-Baptiste Botul. It is a praxis that the paper seeks to emulate, rather than to disavow.