 From an old family in Vexin where he was count of Chaumont, he was the son of a conseiller d'État, the author of many theological works as well as the king's librarian.A relation of Pierre Séguier and a relation via his mother of the three Haberts (Philippe Habert, Germain Habert and Henri-Louis), Paul-Philippe succeeded his father as king's librarian, having joined the royal library as king's reader.Although he had not yet written any works himself he was elected a member of the Académie française in 1654.