Petit-Didier, Matthew a learned French prelate of note, was born in Lorraine in 1659. He very early in life entered the Order of the Benedictines, and later became abbot of Senones, and finally bishop of Macra (in partibus infidelium). He died in 1728. He is the author of several valuable works, among them, Traite theologique sur l'autorite et 'infallibilite des Papes (Avign. 1726, sm. 8vo). This work, asserting the infallibility of the pope, has been attacked by various writers, Romanist as well as Protestant; especially by Lenfant at the end of his Hist. of the Council of Constance. He also published several critical, historical, and chronological dissertations on the Scriptures (1689- 1728). His brother, Jean Joseph, who was a Jesuit, flourished from 1664 to 1756. See Darling, Cyclop. Bibliogr. s.v.; Allibone, Dict. of Brit. and Amer. Auth. s.v.