1360-1417. Cardinal-deacon of Florence and distinguished canon lawyer. Trained in the church's legal traditions at Bologna, he taught canon law at Florence (1385-90) and at Padua (1390-1410), while serving simultaneously in the diplomatic corps of Padua and Venice. He was summoned to Rome by to aid in overcoming the Great Schism.* After participating in the * (1409), he was created a cardinal by * in 1411. His indebtedness to John did not prevent him from supporting the * (1414-18) and recommending the abdication of John as a step toward the reconciliation of the divided halves of Latin Christendom. His Tractatus de schismate (1402-8), based on the work of the decretists and decretalists, made proposals similar to those advocated by ,* an early conciliar theorist. The church was a corporation presided over by the pope. Papal power was of a derivative and limited kind, conferred on the pope by the members of the church. Should the pope fail to call a council in the crisis then rending the church, the right to summon a council would pass immediately to the cardinals and in the event of their inaction to the emperor, the representative of the whole people. Zabarella's defense of the supremacy of a council over a pope, and his untiring efforts at Constance, promoted the eventual healing of the schism, though he himself died before the council had completed its work.
W. Ullmann, The Origins of the Great Schism (1948); E.F. Jacob, Essays in the Conciliar Epoch (1955); B. Tierney, Foundations of the Conciliar Theory (1955).