Pierre d Ailly

Pierre d' Ailly , 1350-1420, French theologian and writer, cardinal of the Roman Catholic Church. He was the teacher of John Gerson and was Gerson's predecessor as chancellor of the Univ. of Paris (1385-95). Ailly figured prominently among the conciliarists working to end the Great Schism (see Schism, Great ). He urged that an ecumenical council be called to name a new pope as the only means of settling the schism. He seems to have been more concerned with a practical solution than with the implications of the conciliar theory. He participated in both the Council of Pisa (see Pisa, Council of ) and the Council of Constance (see Constance, Council of ). At Constance Ailly took part in the trial and condemnation of John Hus. His vast writings embrace theology, philosophy, cosmography, plans for ecclesiastical reform, and French religious verse. One of his works, the Imago mundi, an astronomical compendium, was studied by Columbus.

Bibliography: See studies by J. P. McGowan (1936) and F. Oakley (1964).

d'Ailly, Pierre (1350/1–1420), French theologian. He taught at Paris and in 1397 he became Bp. of Cambrai. His main concern was to find a means of ending the Great Schism. He attended the Council of Pisa, where he supported the newly elected Alexander V; he was made a cardinal by his successor, John XXIII. From 1414 to 1418 he attended the Council of Constance, where he upheld the Conciliar Theory, without, however, entirely approving the ‘Decrees of Constance’. In 1416 he published his influential Tractatus super Reformatione Ecclesiae.

In his doctrinal teaching d'Ailly usually accepted the views of William of Ockham. He held that the existence of God was not a rationally demonstrable truth, and that sin was not inherently evil but sinful only because God wills it to be so. He maintained that bishops and priests received their jurisdiction directly from Christ and not mediately through the Pope, and that neither Pope nor Council was infallible. His views were developed by the Reformers and influenced Gallicanism.