The Cambridge History of English and American Literature in 18 Volumes (1907–21). Volume I. From the Beginnings to the Cycles of Romance. X. English Scholars of Paris and Franciscans of Oxford. § 20. William of Ockham. The teaching of Thomas Aquinas was opposed, not only by the Franciscan realist Duns Scotus, but also by another Franciscan, the great nominalist, William of Ockham. Born (c. 1280) in the little village of that name in Surrey, he became a B.D. of Oxford, and incepted as D.D in Paris, where he had a strong influence over the opponent of the papacy, Marsiglio of Padua. He was probably present at the chapter of Perugia (1322), and he certainly took a prominent part in the struggle against pope John XXII. He was imprisoned at Avignon for seventeen weeks in 1327, but escaped to Italy and joined the emperor, Lewis of Bavaria, in 1328, accompanying him in 1330 to Bavaria, where he stayed for the greater part of the remainder of his life, as an inmate of the Franciscan convent at Munich (d. 1349). He was known to fame as the Invincible Doctor.   68   The philosophical and theological writings of his earlier career included commentaries on the logical treatises of Aristotle and Porphyry, a treatise on logic (the Caius College MS. of which concludes with a rude portrait of the author), as well as Quaestiones on the Physics of Aristotle and on the Sentences of Peter Lombard; the first bok of his questions on the latter having been probably completed before he left Oxford. In the edition of 1495 his work on the Sentences is followed by his Centilogium theologicum. The political writings of the last eighteen years of his life include the Opus nonaginta dierum (c. 1330–3), and the Dialogue between the master and the disciple on the power of the emperor and the pope (1333–43).   69   The philosophical school which he founded is nearly indifferent to the doctrines of the church, but does not deny the church’s authority. While Scotus had reduced the number of doctrines demonstrable by pure reason, Ockham declared that such doctrines only existed as articles of faith. He opposes the real existence of universals, founding his negation of realism on his favourite principle that “entities must not be unnecessarily multiplied.” Realism, which had been shaken, more than two centuries before, by Roscellinus, was, to all appearance, shattered by William of Ockham, who is the last of the great schoolmen   70