JOHN OF JANDUN

Averroist master of arts at Paris; b. Jandun, Ardennes, France, c. 1275; d. Todi, Italy, 1328. He studied arts at the University of Paris, where he taught and became an intimate friend of marsilius of padua. In 1316 he obtained a canonry at Senlis. The foremost advocate of Latin Averroism in his day, he described himself as "a mimic of Aristotle and averroËs" [In Metaph. (Venice 1525) folio 84]. In his commentaries on Aristotle's De anima (Venice 1473), Physics (Venice 1488), De caelo et mundo (Venice 1501), Parva naturalia (Venice 1505), and Metaphysics he strongly defended all the basic teachings of Latin Averroism, especially the eternity of the world and motion, unicity of the human intellect, denial of personal immortality, and personal responsibility in moral actions (see averroism, latin; intellect, unity of; scholasticism, 1). Unlike siger of brabant and boethius of sweden, he explicitly taught the doctrine of a double truth and gave greater weight to truths demonstrated by reason than to truths revealed by faith (see dou ble truth, theory of). While teaching in Paris he collaborated with or at least gave some kind of assistance to Marsilius of Padua in the composition of Defensor pacis. When authorship of this antipapal work became known in 1324, he was forced to leave Paris with Marsilius. In 1326 he sought the protection of louis iv the Bavarian, together with Marsilius of Padua, william of ockham, and michael of cesena. In 1327 many propositions extracted from Defensor pacis were condemned by john xxii; John of Jandun was explicitly mentioned in the bull of condemnation. Louis IV nominated him bishop of Ferrara in 1328, but it is doubtful that he was ever consecrated.

Besides commenting on the works of Aristotle, he wrote De laudibus Parisius, Quaestiones de formatione foetus, Quaestiones de gradibus et pluralitate formarum, Tractatus de specie intelligibili, Duo tractatus de sensu agente, and a commentary on Averroës' De substantia orbis.

While professedly admitting all the truths of faith, he adamantly denied that reason could prove that the higher faculties of man's soul—the possible intellect, the agent intellect, and the will—are immaterial and spiritual. Similarly, he believed in creation ex nihilo, although this doctrine seemed to him to be absolutely incomprehensible. He remarked, "I believe that this is true, but I do not know how to prove it; good for those who do" (sed demonstrare nescio; gaudeant qui hoc sciunt ). Because of many such remarks, it is impossible to know whether John scoffed at Christian faith or merely sneered at the simplicity of theologians who pretended to prove what they held only on faith.

Bibliography: a. pompei, Enciclopedia filosofica, 4 v. (Venice-Rome 1957) 2:760–761. n. valois, "Jean de Jandum et Marsile de Padoue," Histoire littéraire de la France, 33 (1906) 528–623. e. gilson, History of Christian Philosophy, 522–524. e. santovito, Enciclopaedia cattolica, ed. p. paschini et al., 12 v. (Rome 1949–54) 6:566. b. nardi, Sigieri di Brabante nel pensiero del Rinascimento italiano (Rome 1945). u. chevalier, Répertoire des sources historiques du moyen-âge. Biobibliographie, 2 v. (2d ed. Paris 1905–07) 2426. s. mcclintock, Perversity and Error: Studies on the Averroist John of Jandun (pa. Bloomington, Ind.1956).

[j. a. weisheipl]