Charles-Irénée Castel de Saint-Pierre (1658–1743)

Charles-Irénée Castel, abbé de Saint-Pierre, was born to an aristocratic family at the château of Saint-Pierre-Église near Cherbourg, where his father, the marquis de Saint-Pierre, served as an official. Unsuited to a military career owing to his poor health, he became a priest.

He was introduced by family connections into the salons of Madame de La Fayette and the Marquise de Lambert in Paris. In 1695, he was elected to the Académie française, although he had not yet produced any notable work, during a turbulent period in the organization known as the Quarrel of the Ancients and the Moderns. The same year, he went to court as chaplain to Madame, King Louis XIV's sister-in-law. He worked on his ideas about universal peace for several years and published his first book, Projet pour rendre la paix perpétuelle en Europe, in 1712; it was followed by several more. For criticizing royal policies, he was expelled from the Académie.

In 1724, with Pierre-Joseph Alary, he founded the Club de l'Entresol, an independent discussion group modeled on English clubs; it was closed by King Louis XV in 1731.