The present study uses modern Molière criticism as a way of understanding Mme de Sévigné. In both Molière and Mme de Sévigné there is evidence of esprit or wit, that intellectual facility which perceives contrasts. Moliéresque critical theory would call this perception the "Imposteur" technique. As the opening lines of Molière's Lettre sur l'Imposteur propose, it is a "discours du ridicule" where ridicule is defined as the incongruous and the unreasonable. This notion depends on an act of intelligent judgement of what actually constitutes the normatively reasonable, and consequently, it presupposes the same perspective on the part of the reader/spectator. Implicit to both irony and ridicule is the complementarity necessary between the giver and the receiver of the message. The application of moliéresque critical theory to the Correspondance of Mme de Sévigné can contribute to a renewed appreciation of the highly intellectual quality of the comic genius of a "spirituelle marquise," a mother who desperately wanted to entice a distanced daughter to regularity in an epistolary exchange, a woman of wit and irony.