Habert, Isaac doctor of the Sorbonne, the first Parisian theologian who wrote against Jansenius. He was a native of Paris, studied at the Sorbonne, was appointed canon of the cathedral of Paris, and in 1645 bishop of Vabres. He filled this post for twenty-three years, was reputed a very pious man, and died at Pont de Salars, near Rodez, in 1668. In 1641 he accused Jansenius of holding heretical doctrines on forty points, and thereby provoked Antoine Arnauld to answer him in his Apologie, in which he sought to prove the identity of the doctrines of Jansenius and St. Augustine. Habert nevertheless remained a declared enemy of Jansenius, and to him is ascribed the authorship of the letter sent to pope Innocent X in 1651, and signed by eighty-five bishops, praying him to decide the question finally. The most noteworthy of his works are: De gratia ex partibus graecis (1646): — De consensu hierarchice et monarchice (Paris, 1640): — De cathedra seu primatu S. Petri (Paris, 1645). He translated also into Latin the ceremonial of the Eastern Church, under the title Liber pontficalis, Greece et Latine c. not. (Paris, 1643, fol.). — Herzog, Real- Encyklopadie, 5, 439; Hoefer, Nouv. Biog. Géneralé, 23, 13.