Leporius a monastic who flourished in the second half of the 4th and the early part of the 5th century, a native of Gaul, embraced asceticism under the auspices of Cassianus about the opening of the 5th century, at Marseilles, where he enjoyed a high reputation for purity and holiness. Advancing the view that man did not stand in need of divine grace, and that Christ was born with a human nature only, he was excommunicated in consequence of these heretical doctrines. He betook himself to Africa, and there became familiar with Aurelius and St. Augustine, by whose instructions he profited so much that he not only became convinced of his errors, but drew up a solemn recantation addressed to Proculus, bishop of Marseilles, and Cyllinnius, the bishop of Aix (see below as to the title and value of this treatise), while four African prelates bore witness to the sincerity of his conversion, and made intercession on his behalf. Although now reinstated in his ecclesiastical privileges, Leporius does not seem to have returned to his native country, but, laying aside the profession of a monk, was ordained a presbyter by St. Augustine, A.D. 425, and appears to be the same Leporius so warmly praised in the discourse De Vita et Moribus Clericorum. We know nothing further regarding his career except that he was still alive in 430 (Cassianus, De Incarn. 1:4). The treatise above alluded to is still extant, under the title Libellus emendationis sie satifactionis ad Apiscopos Galliae, sometimes with the addition Confessionem Fideii Catholicae continens de Mysterio Incarnationis Christi, cum Erroris pristini Detestatione. It was held in very high estimation among ancient divines, and its author was regarded as one of the firmest bulwarks of orthodoxy against the attacks of the Nestorians.
Some scholars in modern times, especially Quesnel, who has written an elaborate dissertation on the subject, have imagined that we ought to regard this as a tract composed and dictated by St. Augustine, founding their opinion partly on the style, and partly on those terms in which it is quoted in the acts of the secoend Council of Chalcedon and early documents, and partly on certain expressions in an epistle of Leo the Great (165, edit. Quesnel); but their arguments are far fromrr being conclusive, and the hypothesis is generally rejected. Fragments of the Libellus were first collected Sismondi from Cassianus, and inserted in his collection of Gaulish councils (1:52). The entire work was soon discovered and published by the same editor in his Opuscula. Dogmatica Veterumn quinque Sacristorum (Par. 1630, 8vo), together with the letter of the African bishops in favor of Leporius. It will be found also in the collection of councils by Labbe (Paris, 1671, folio); in Garnier's edition of Marisus Mrcator (Paris, 1673, fol.), 1:224; in the Bibliotheca. Patrune Max. (Lugd. 1677), 7:14; and in the Biblioteca Patrum of Galland (Ven. 1773), 9:396. Consult the dissertation of Quesnel in his edition of the works of Leo, 2:906 (ed. Paris); Histoire Litteraire de la France, 2:167 the second dissertation of Garnier, his edition of M. Mercantor, 1:230; the Prolegomena of Galland: Schoncmannn, Biblioteca Patr. Latt. 2, § 20. — Smith, Dict. Greek and Roman Biography, vol. 2, s.v.