A theological system named after its author, Cornelius Jansenius, Bishop of Ypres, Belgium. The essential points of the system are:

  • human nature has been radically corrupted by original sin
  • man, not free to resist either the delectations of grace, or concupiscence, does good or evil irresistibly, though voluntarily, according as he is dominated by grace or by concupiscence
  • Christ did not die for all, but only for those who are predestined to salvation
  • the sacraments can be received only after long and severe preparation
  • Communion is looked upon as a reward rather than a remedy
  • God should be addressed always with fear and trembling

These tenets, which bear close resemblance to Calvinism, were set forth mostly in two books, the 1540 Augustinus of Jansenius, so-called because it was supposed to contain the pure doctrine of Saint Augustine on the fall of man and on grace, and the 1643 book on Frequent Communion by Antoine Arnauld. Jansenius had died before his book was published, and the true promoters of Jansenism were Duvergier de Hauranne, Abbot of Saint Cyran, and the celebrated Arnauld family, notably Mere Angelique, Abbess of Port-Royal of which de Hauranne was the austere and rigorist chaplain.

Five propositions extracted from the Augustinus were condemned in 1653, a condemnation which the Jansenists tried to evade by having recourse to the famous distinction: the propositions are erroneous indeed, but de facto they are not in the Augustinus. At this juncture the Provincial Letters of Pascal brought the controversy before the public and were a great asset in favor of the Jansenists by indicting and ridiculing their arch-enemies, the Jesuits. In 1659, Pope Clement IX granted a kind of amnesty to them, and the Jansenists made good use of it to spread their doctrines.

After the death of Antoine Arnauld, P. Quesnel, an Oratorian, became the leader, and reproduced the teachings of Jansenius and Arnauld in his Reflexions morales sur le nouveau testament. The book was condemned in 1713 in the Bull Unigenitus, the most famous document bearing on the subject. The Jansenists immediately appealed from the pope to a general council, and were followed by some of the bishops and clergy. Hence the distinction between the Appellants who refused to receive the Bull and the Acceptants who did receive it.

The crisis which lasted for 25 years was intensified by the fact that the sacraments were refused to the Appellants. Priests were, as a result, involved in countless lawsuits and king and parliament were being constantly appealed to. The antics from 1727 to 1732 of the Convulsionnaires at the grave of the Deacon Paris in the Medard Cemetery threw ridicule on Jansenism, and it declined in the course of the 18th century. However, it survived in Febronianism, Josephinism, and Gallicanism. In France its spirit was found until the middle of the 19th century even in text-books of seminaries. One important group of Jansenists still exists in the Netherlands, where it is governed by the archbishop of Utrecht and the bishops of Haarlem and Deventer.