The anonymous tract Entretien d’un Catholique & d’un Protestant Calviniste was published in 1684 together with two works by Marin Grosseteste des Mahis, the former minister at Orléans who had abjured the Reformed faith the previous year. The tract was probably a response to Reformed criticism of the Catholic veneration of the relics of St Aignan at Orléans. During a drought in July 1684, the relics were carried in procession and the clergy led the populace in prayers for the saint’s intercession. Adopting a broad perspective, the tract defended this Catholic practice and attacked Reformed attitudes, which had seen the destruction of relics at Orléans and elsewhere during the religious wars of the late sixteenth century. The tract engaged directly with the criticism of the cult of relics during the seventeenth century by Reformed authors such as Jean Daillé, Mathieu Bochart, and Pierre Jurieu. Relics were just one aspect of the wider confessional disputes over religious practice and the True Church on the eve of the Revocation of the Edict of Nantes. Nonetheless, l’Entretien sheds light on the defense of the veneration of relics as well as illustrating something of the tensions between the Catholic and Reformed communities at Orléans.