Lefranc was an Abbot at Caen's seminary of the Congregation of Jesus and Mary; he was opposed to Jansenism [REF].
His book, Le Voile levé pour les curieux, ou le Secret de la Révolution révélé, à l'aide de la Franc-Maçonnerie, published in 1791, advanced, for the first time, the thesis that a Masonic conspiracy was behind the French Revolution.