CONCILIARISM. — An ecclesiological error according to which the ecumenical council is superior to the pope. The remote origin of c. is found in the juridical principle (Decree of Gratian, dist. XL, c. 6) according to which the pope may be judged by the Church in the event of heresy. This maxim, encountered throughout the Middle Ages, spread the idea that there were cases in which the pope could be subjected to the judgment of his subjects. When, at the end of the thirteenth century and the beginning of the fourteenth, the struggles of Boniface VIII with Philip the Fair and of John XXII with Louis the Bavarian shook the authority and prestige of the Roman pontiff in the minds of many, the old principle was invoked and expanded with further elaborations: not only in the case of heresy, but also when, in the exercise of his power, the pope oversteps his bounds, he may be called to order; it was precisely at that time that appeals to a council became frequent.
In this climate Marsilius of Padua’s Defensor pacis (v.) arose, according to which Jesus Christ established no vicar of his on earth who might be head of the Church, since all ministers of religion possess equal powers; the papacy is a creation of the emperor, who can correct and depose the holders of the tiara; the supreme organ of ecclesiastical government is not the papacy but the ecumenical council, convoked by imperial authority and composed not only of bishops and priests but also of laymen; its decrees come immediately after Scripture and before the papal decretals and have full application by virtue of imperial power. If the ecumenical council preserves for the pope the directive power which, through a combination of circumstances, was formerly entrusted to the bishop of Rome, this does not mean that such a mandate cannot be revoked.
Despite the condemnation by John XXIII, these errors, championed and amplified (e.g., by the denial of infallibility) by the rebellious Minorite William of Ockham (v.), spread widely, especially in Bavaria. When the Western Schism (1378–1417) afflicted the Church, many, even those of good intentions, found in these theories a way out of so many evils. At the very beginning of the schism, two German doctors of the University of Paris reduced conciliar doctrine to a system: Conrad of Gelnhausen and Henry of Langenstein. The former published an Epistola concordiae in 1386, the latter an Epistola pacis in 1379, in which the necessity of an ecumenical council is advocated and a broad plan of reform proposed; but while Conrad attributes supreme power to the bishops summoned, Henry sees its origin in the community of the faithful. These theories would undergo further development in Peter d’Ailly (1350–1420), a brilliant doctor and chancellor of the University of Paris. A convinced Ockhamist on several doctrinal points, from 1380 onward he became the spokesman for the doubts that, amid so many upheavals, had disturbed the minds of the best spirits. It is incredible, he says, that the Lord founded the firmitas Ecclesiae on Petri infirmitate, since Peter and his successors have erred so many times; it must therefore be held that the Church is founded on Jesus Christ and that the pope is not essential to it; hence all power descends directly from God to the bishops and priests, who, assembled in council, constitute the supreme authority of the Church, and are therefore superior to the pope. He may be called head of the Church only ministerialiter exercens and administrative dispensans; and since he can err, and even fall into heresy, he must in such a case be corrected and also deposed. Only the universal Church is infallible, in the sense that, even if the entire clergy should fall into error, there will always be some simple soul and some devout layman able to preserve the deposit of Revelation. Such were the ideas of the able chancellor, who soon became archbishop of Cambrai (1397) and an Avignonese cardinal (1411), and one of the presidents of the Council of Constance. Gerson (v.), who went beyond his master. Whereas Peter d’Ailly, developing the ideas of Conrad of Gelnhausen, conceived the Church as an episcopal aristocracy, Gerson, following the line traced by Henry of Langenstein, first became an advocate of a moderated democracy (parish priests have a conclusive vote in the council like the bishops, since both are of divine origin), then fell into multitudinarianism, teaching that the entire mystical body of the faithful has equal rights in ecclesiastical government, which it nevertheless transmits to the bishops and the pope. Hence the logical deduction that the ecumenical council, but also the entire community, can call the pope to his duty and, if necessary, depose him.
Gerson, a truly pious man, was better in his conduct than in his ideas. Meanwhile, however, these ideas, under the aegis of so great a man, spread and were practically applied in the Councils of Constance and Basel; and while they penetrated the minds of many writers, they fostered the development of contemporary heresies (Wyclif and Hus) and subsequent ones (Lutheranism, Calvinism, Anglicanism), only to take refuge, after the Council of Trent, among those French Catholics who, in the name of Gallican liberties (v. GALLICANISM), opposed the free exercise of papal authority for centuries. The error remained alive even at the First Vatican Council, where, however, it received its deathblow (Denz-U, 1830).