English secular scholastic, called Doctor planus and Doctor perspicuus; b. Yorkshire, 1275; d. after 1344. He was master of arts of Oxford by 1301 and fellow of Merton College from 1301 to 1305. Ordained in June 1309, he studied theology in Paris under Thomas of Wilton by 1310, becoming a master in theology around 1322. While traveling on the king's business, he held a disputation de quolibet at Toulouse in 1327 and another at Bologna in 1341. From 1309 until his death he held, with dispensation, a plurality of benefices, including a canonry at York and another at Salisbury. Associated with the highest ranks of English society, he was sent in 1327 as envoy of King Edward III to the Papal Curia for the canonization of Thomas, Earl of Lancaster (d. 1322); according to Holinshed's Chronicles, he was almoner to Philippa of Hainault at her marriage to Edward III in 1328 and tutor to the Black Prince (1330–76). Around 1333 he was one of the clerks in the household of richard of bury, Bishop of Durham, and in 1336 he was a clerk in the King's household. When "certain of his rivals" had him imprisoned for having two oak trees cut in Sherwood Forest, Richard of Bury secured his pardon, and he was again abroad on king's business in 1338. In November 1343 he was at Avignon where he presented a copy of his Expositio librorum politicorum to clement vi.
From at least 1301 until 1337 he wrote commentaries on Aristotle's logic, making successive revisions of his works; notabilia; treatises on the Parva logicalia; and original works, notably De puritate artis logicae (two versions) and De suppositionibus. The closing part of his Tractatus de universalibus realibus contains probably the earliest indication of his antagonism to the nominalism of william of ockham, whom he strongly refuted in later works. He wrote also commentaries on Aristotle's Ethics and the Libri naturales in the form of both questions and exposition. Many of his original works deal with problems of natural philosophy: De intensione et remissione formarum, De potentiis animac, De substantia orbis, and De materia et forma. His most popular work was De vitis et moribus philosophorum, the first treatise of its kind in the Middle Ages, dealing with the lives and anecdotes of philosophers.
Perhaps the first to make syllogistics a subdivision of consequences, Burley anticipated later developments in his treatment of negation and in his conception of the formal character of logic. In his treatment of universals, he was an Aristotelian realist.
Bibliography: a. b. emden, A Biographical Register of the University of Oxford to A. D. 1500, 3 v. (Oxford 1957–59) 1:312–314. c. martin, "Walter Burley," Oxford Studies Presented to Daniel Callus (Oxford 1964). p. m. m. duhem, Le Système du monde: Histoire des doctrines cosmologiques de Platon à Copernic (5 v. Paris 1913–17; repr. 10 v. 1954–59) 6:678–680; Études sur Léonard de Vinci, 3 v. (Paris 1906–13; repr. 1955). p. bÖhner, Medieval Logic (Chicago 1952). a. n. prior, "On Some Consequentiae in Walter Burleigh," New Scholasticism 27 (1953) 433–446. s. h. thompson, "Walter Burley's Commentary on the Politics of Aristotle," Mélanges Auguste Pelzer (Louvain 1947) 557–578.
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