Magni, Valerian a celebrated Italian ecclesiastic, was born in Milan, Italy, in 1586; was appointed by pope Urban VIII apostolical missionary to the Northern kingdoms; influenced the pope to imprison the Jesuitesses in 1631; was himself imprisoned in Vienna some time afterwards, through the influence of the Jesuits, for having said that the pope's primacy and infallibility were founded on tradition and not on Scripture, but regained his liberty through the favor of the emperor Ferdinand III, after having written warmly against the Jesuits. He died at Saltzburg in 1661. Magni was celebrated as a controversial writer against the Protestants; also for his philosophical works in favor of Des Cartes and against Aristotle. One of his apologetical letters may be found in the collection called Tuba Magna, vol. ii. — Hook, Eccles. Biog. 7:209.