Whatever his merits as a writer or as a philanthropist, Gregoire's name lives in history mainly by reason of his wholehearted effort to prove that Catholic Christianity is not irreconcilable with modern conceptions of political liberty. In this effort he was defeated, mainly because the Revolution, for lack of experience in the right use of liberty, changed into a military despotism which allied itself with the spiritual despotism of Rome; partly because, when the Revolution was overthrown, the parties of reaction sought salvation in the "union of altar and throne." Possibly Gregoire's Gallicanism was fundamentally irreconcilable with the Catholic idea of authority. At least it made their traditional religion possible for those many French Catholics who clung passionately to the benefits the Revolution had brought them; and had it prevailed, it might have spared France and the world that fatal gulf between Liberalism and Catholicism which Pius IX.'s Syllabus of 1864 sought to make impassable. Besides several political pamphlets, Gregoire was the author of _Histoire des sectes religieuses, depuis le commencement du siecle dernier jusqu'a l'epoque actuelle_ (2 vols., 1810); _Essai historique sur les libertes de l'eglise gallicane_ (1818); _De l'influence du Christianisme sur la condition des femmes_ (1821); _Histoire des confesseurs des empereurs, des rois, et d'autres princes_ (1824); _Histoire du mariage des pretres en France_ (1826). _Gregoireana, ou resume general de la conduite, des actions, et des ecrits de M. le comte Henri Gregoire_, preceded by a biographical notice by Cousin d'Avalon, was published in 1821; and the _Memoires ... de Gregoire_, with a biographical notice by H. Carnot, appeared in 1837 (2 vols.). See also A. Debidour, _L'Abbe Gregoire_ (1881); A. Gazier, Etudes sur l'histoire religieuse de la Revolution Francaise (1883); L. Maggiolo, La Vie et les oeuvres de l'abbe Gregoire (Nancy, 1884), and numerous articles in _La Revolution Francaise_; E. Meaume, _Etude hist. et biog. sur les Lorrains revolutionnaires_ (Nancy, 1882); and A. Gazier, _Etudes sur l'histoire religieuse de la Revolution Francaise_ (1887).