 A nephew of Bishop Potier of Beauvais, a close friend of the Jansenist Hermant, Lamoignon was supposed to sympathize with Port Royal, but he chose René Rapin, a Jesuit, as tutor for his sons, whom he also brought into close acquaintance with Bourdaloue.When in 1664 the Jansenists deferred to the Parlement a confutation of Pascal's "Provinciales" written by the Jesuits, the decree which condemned this book nevertheless spared the Jesuits.On this occasion Lamoignon said to the king that he had been "a witness of the unfair outbursts of the Jansenists in all the differences they had with the Society of Jesus; and this Jansenist party, which was being formed in the kingdom on the dissemination of the new teaching, was but a cabal which would become pernicious to the State".