The Papacy in the Late Middle Ages
Attempts at Resolution
There had been rival popes in the past, several times. A few times, the rival pope had stuck around for quite a long time. The initial thinking was that this split would be healed the way the others had been; namely, that "God would decide." That is to say, one of the popes would die and that would be that.
When Urban died in Rome, however, and a successor was immediately elected, it was clear that this wasn't going to happen. Moreover, the rival popes had rival courts, strong supporters among various kings, and in general had the resources to last through generations. God was not going to decide.
A second course was proposed, fairly early, and continued to have favor in some circles: both popes would voluntarily resign, clearing the way for the election of a compromise candidate. At one time or another, the rival popes even agreed to this arrangement, but then the difficult matter of timing arose. Neither would be the first to resign, so both had to resign together. But agreed dates came and went, no rival could be induced to meet in the same city with the other, and this course, too, seemed to be barren of results.
Some began to argue that the whole Church together might have authority to judge in this matter, and that a Council might represent the Church and choose a pope. It had long been recognized that a general council could speak on matters of faith, but never had it been suggested that a council might choose a pope. As the Schism dragged on, though, pressure for a General Council grew.
By the early 1400s, even cardinals were urging this last course. Royal support was weak at the time, so there might not be effective opposition to a deposition. But there was a difficult problem to resolve. Since there were two popes, it wasn't at all clear who could call such a council.