Occam, Or Ockham, William Of, an English scholastic philosopher, born at Occam in Surrey about 1270, died in Munich, April 7, 1347. He was of humble parentage, was educated at Merton college, Oxford, and was appointed in 1302 first prebendary of Bedford, and in 1305 of Stowe. On the controversy between Philip the Fair and Boniface VIII. he opposed the pretensions of the pope. In 1319 he resigned his livings and became a Franciscan monk. He was sent to Paris to complete his studies under Duns Scotus, his old master at Oxford, whose most formidable adversary he afterward became. Having obtained his doctor's degree, he taught theology with such success as to win the appellation of "the invincible doctor," and subsequently was a strenuous adversary of the papal claims of sovereignty over secular princes. In 1322, in the general Franciscan chapter assembled at Perugia, he argued against Pope John XXII. that Christian priests neither individually nor in community should be the possessors of property. His manifesto, entitled Disputatio super Potest//te Ecclesias-tica Pradatis atque Principihus Terrarum commissa, was condemned by the pope; but, supported by Michael of Cesena, general of his order, he continued to assail the practices of the holy see.

In the same year he was ap-pointed provincial of the Franciscans in England, and while there advocated his anti-papal doctrines with still greater freedom. Summoned with his disciples in 1327 by Pope John XXII. before the court of Avignon, he fled to the court of the emperor Louis the Bavarian, where he remained till his death. In his age he was the champion of the Franciscans and the nominalists against the Dominicans and the realists. His philosophical and theological writings are: Quodlibeta Septem (Paris, 1487; Strasburg, 1491); Summa totius Logices, or Tractatus Logices in trcs partes divisvs (Paris, 1488; Venice, 1591; Oxford, 1675); Qvas-tiones in Lilros Physicorum (Strasburg, 1491 and 1506); Qucpstiones et Decisiones in quatvor Lihros Sententiarum (Lyons, 1495); Centilo-gium Theologicum (Lyons, 1496); Expositio Aurea super tota Arte Vetere (Bologna, 1496); Opus nonaginta Dicrum contra Errores Joan-nis XXII Utili Dominio Rervm Ecclesiasti-carum (Lyons, 1495 and 1496, and also in Gol-dast's MortarcMa Romani Imperii, 3 vols, fob, Hanover, 1611-14); and the above mentioned Disputatio (Paris, 1598, and in the Monarcliia).