Church History, a sect of the Roman Catholics in France, who followed the opinions of Jansenius, bishop of Ypres, and doctor of divinity of the universities of Louvain and Douay, in relation to grace and predestination.

In the year 1640, the two universities just mentioned, and particularly Father Molina and Father Leonard Celsus, thought fit to condemn the opinions of the Jesuits on grace and free-will. This having set the controversy on foot, Jansenius opposed to the doctrine of the Jesuits the sentiments of St Augustine; and wrote a treatise on grace, which he entitles Augustinus. This treatise was attacked by the Jesuits, who accused Jansenius of maintaining dangerous and heretical opinions; and afterwards, in 1642, obtained from Pope Urban VIII. a formal condemnation of the treatise written by Jansenius: when the partizans of Jansenius gave out that this bull was spurious, and composed by a person entirely devoted to the Jesuits. After the death of Urban VIII., the affair of Jansenism began to be more warmly controverted, and gave birth to an infinite number of polemical writings concerning grace. And what occasioned some mirth, was the titles which each party gave to their writings; one writer published The torch of St Augustine, another found Snuffers for St Augustine's torch, and Father Veron formed A Gag for the Jansenists, &c. In the year 1650, 68 bishops of France subscribed a letter to Pope Innocent X. to obtain an inquiry into and condemnation of the five following propositions, extracted from Jansenius's Augustinus:

1. Some of God's commandments are impossible to be observed by the righteous, even though they endeavour with all their power to accomplish them. 2. In the state of corrupted nature, we are incapable of resisting inward grace. 3. Merit and demerit, in a state of corrupted nature, do not depend on a liberty which excludes necessity, but on a liberty which excludes constraint. 4. The Semipelagians admitted the necessity of an inward preventing grace for the performance of each particular act, even for the beginning of faith: but they were heretics in maintaining that this grace was of such a nature, that the will of man was able either to resist or obey it. It is Semipelagianism to say, that Jesus Christ died, or shed his blood, for all mankind in general.

In the year 1652, the pope appointed a congregation for examining into the dispute in relation to grace. In this congregation Jansenius was condemned; and Janfeinists, the bull of condemnation, published in May 1653, filled all the pulpits in Paris with violent outcries and alarms against the heresy of the Janfeinists. In the year 1656, Pope Alexander VII. issued another bull, in which he condemned the five propositions of Janfein. However, the Janfeinists affirm, that these propositions are not to be found in this book; but that some of his enemies having caused them to be printed on a sheet, inserted them in the book, and thereby deceived the pope. At last Clement XI. put an end to the dispute by his constitution of July 17. 1705; in which, after having recited the constitutions of his predecessors in relation to this affair, he declares, "That in order to pay a proper obedience to the papal constitutions concerning the present question, it is necessary to receive them with a respectful silence." The clergy of Paris, the same year, approved and accepted this bull, and none dared to oppose it.

This is the famous bull Unigenitus, so called from its beginning with the words Unigenitar Dei Filius, &c., which has occasioned so much confusion in France.