PIERRE D´AILLY (1417)

Theologian, cardinal, and advocate of church reform whose chief aim was to heal the Great Schism of the Western Church (1378-1417).


He studied at the College of Navarre of the University of Paris, where he became doctor of theology (1380). It was at that time that d´Ailly began to take the position that a general council was superior to the pope, whom it might depose if necessary. In 1381 he suggested convoking a general council in a effort to end the schism.


D´Ailly became master of the College of Navarre in 1384 and later was made chancellor of the university and the King´s confessor and almoner (1389). He displeased the university, however, by supporting the antipope Benedict XIII, who appointed him bishop of Le Puy (1395) and then bishop of Cambrai (1397). He gradually broke with Benedict, who, with the Roman pope Boniface IX, refused to abdicate to heal the schism. D´Ailly then returned to his old conciliar doctrine, which steadily became more extreme.


He played a prominent part in the Council of Pisa (1409), which declared Benedict and the new Roman pope Gregory XII deposed and elected a third, the conciliar pope Alexander V, who was succeeded the following year by John XXIII. John made d´Ailly a cardinal (1411), bishop of Orange, and his legate to Germany (1413). But since the schism persisted, there being now three popes instead of two, d´Ailly favoured calling a new general council, which was convened at Constance (1414-18). He was influential in the decisions of Constance, which called for the abdication of John XXIII, condemned the Hussites (heretical followers of the Bohemian Reformer Jan Hus), supported conciliarism, and accepted a compromise on the roles of the council and the cardinals in order to elect a new pope, Martin V (November 1417).


The possibility that d´Ailly might be elected pope was ruled out by a hostile coalition of Italians, Germans, and English. He retired to Avignon, where he was legate for Martin.


D´Ailly was the author of several influential works. Although many of his views on the constitution of the church were later rejected as heretical, particularly inasmuch as they were echoed by Protestant Reformers, they were adopted in his time as the only apparent way of ending the Great Schism. Interested inn science, he advocated calendar reform (later effected by Pope Gregory XII) and wrote his Image of the World, which supported the idea that the East Indies could be reached by sailing west.