CIENFUEGOS, ÁLVAREZ. - Celebrated Spanish Jesuit theologian, bishop, and cardinal, b. at Oviedo (Asturias) on 27 Feb. 1657, d. at Rome on 19 Aug. 1739. Having entered the Society of Jesus (1676), he taught philosophy at Santiago and theology at the University of Salamanca. During the War of the Spanish Succession he sided, together with J. Thomas Henriquez, with Charles III, Archduke of Austria, who entrusted him with important negotiations with the King of Portugal. But after the Bourbon victory he was unable to return to his homeland. After remaining for some time in Lisbon, he was summoned to Vienna by Charles III, who had become emperor under the name Charles VI, and who sent him to England and Holland on further state missions. He subsequently became the emperor’s plenipotentiary minister to the Holy See, cardinal (1720), bishop of Catania (1722), archbishop of Monreale in Sicily (1724), and bishop of Fünfkirchen in Hungary (1735).
His two celebrated works, Aenigma theologicum (Vienna 1717), on the Most Holy Trinity, and Vita abscondita, seu speciebat eucharisticis velata (Rome 1728), met with lively approval for their originality and acuteness, but also with widespread disapproval for the boldness of certain opinions (e.g., concerning the real presence of Jesus Christ and the essence of the sacrifice of the Mass).