He assisted St Vincent de Paul in his missionary work and was recommended by him to Richelieu for the episcopate. Appointed bishop of Alet in June 1637, he governed his diocese with great zeal and a spirit of reform. Allied with Arnauld and the Port-Royal movement, he at first refused to sign the papal condemnation (May 1653) of the five propositions of Jansenius, yielding only in 1668 under Clement IX. By decree of 18 Jan. 1667 his Mandement sur la signature du formulaire had been placed on the Index. Together with Caulet, Pamiers (v.), he appealed to the Pope against the right of régale which Louis XIV sought to extend to all the bishops of France (10 Feb. 1673).
BIBL.: J. Carèyre, P., in D'ThC, XII, 1, cols. 77-79, with bibliography: E. Dejean, Un prélat indépendant au XVIIe siècle, Paris 1909; Pastor, XIV, part 1, passim; P. Coste, Monsieur Vincent, Paris 1932, passim.