In 1519 at the disputation of Leipzig Luther was reluctantly forced to admit that even early ecumenical councils contradicted his teaching. His solution was to propose that such councils can err, and that he was still right. Even so, he still held councils to be authoritative. In 1520, in his Letter to the Christian Nobility of the German Nation, he argues that even private Christians, such as himself, should be allowed to call a council to settle disputes. He thought that reserving that power for the Pope was a barrier to reform and was also historically inconsistent. That is, Luther was consistently of the mind that the Pope could be corrected by a council, and that a council needed to be convened to address the situation at hand.
Refresh my recollection. Is '1520' a bigger number or a smaller number than '1054'?
Again, the Protestant objection that Trent doesn't count because it wasn't "ecumenical" (in the sense of including the Eastern Churches) is hogwash. The Protestants of the 16th century would have accepted no such argument. Luther and Calvin believed councils to be fallible but also authoritative (including the first seven). They never rejected late councils on the mere basis of "ecumenicity." Finally, the presence of the East at Trent would not have altered the fate of Lutheranism.
