Jansenism a set of doctrines advanced by European Roman Catholic reformers, clergy, and scholars in the seventeenth and eighteenth centuries, characterized by a predestinarianism that emphasized Adam’s fall, irresistible efficacious grace, limited atonement, election, and reprobation. Addressing the issue of free will and grace left open by the Council of Trent (1545–63), a Flemish bishop, Cornelius Jansen (1585–1638), crystallized the seventeenth-century Augustinian revival, producing a compilation of Augustine’s anti-Pelagian teachings (Augustinus). Propagated by Saint Cyran and Antoine Arnauld (On Frequent Communion, 1643), adopted by the nuns of Port-Royal, and defended against Jesuit attacks by Pascal (Provincial Letters, 1656–57), Jansenism pervaded Roman Catholicism from Utrecht to Rome for over 150 years. Condemned by Pope Innocent X (Cum Occasione, 1653) and crushed by Louis XIV and the French clergy (the 1661 formulary), it survived outside France and rearmed for a counteroffensive. Pasquier Quesnel’s (1634–1719) ‘second Jansenism,’ condemned by Pope Clement XI (Unigenitus, 1713), was less Augustinian, more rigorist, and advocated Presbyterianism and Gallicanism. J.-L.S.