HABERT, ISAAC. - French bishop and theologian, b. in Paris c. 1600, d. at Pont-de-Salars, near Rhodez, 15 Sept. 1668. Having graduated in theology at the Sorbonne in 1626, he shortly afterwards obtained a canonry in the cathedral of Paris. Appointed preacher to the King, he energetically opposed Jansenism, which he attacked in his sermons at Notre-Dame from 1641 onward. Antoine Arnauld rose against H. with a polemical writing, to which he replied with the work La défense de la foy de l'Eglise et de l'ancienne doctrine de Sorbonne, touchant les principaux points de la Grâce (Paris 1644). Appointed bishop of Vabres (1645), his pastoral duties slowed his literary activity. He was the author of the letter that the French bishops sent to Innocent X in 1651, requesting the censure of Jansenist doctrines on Grace.
Works: De consensu hierarchiae et monarchiae, adversus paraeneticum Optati Galli schismatum fictoris (Paris 1640), written against the Optatus Gallus of C. Hersent, and translated into French by L. Giry under the title De l'union de l'Eglise avec l'Etat (ibid. 1641); the Latin translation of the Archieraticon, Liber pontificalis Ecclesiae Graecae (ibid. 1643), which constitutes an excellent source of information on Greek liturgy; Theologiae graecorum Patrum vindicatae circa universam materiae gratiae libri III (ibid. 1646); In b. Pauli epistolae tres episcopales ad Timotheum et Titum et unam ad Philemonem expositio perpetua (ibid. 1656).