The whole affair was given a wider publicity than it had hitherto attained, and at the same time Luther was pushed to a more advanced position than he had yet reached, by the attack of a theologian of Ingolstadt, John Eck.

When he assailed the Theses on the ground that they seriously impaired the authority of the Roman see, Luther retorted: {69} The assertion that the Roman Church is superior to all other churches is proved only by weak and vain papal decrees of the last four hundred years, and is repugnant to the accredited history of the previous eleven hundred years, to the Bible, and to the decree of the holiest of all councils, the Nicene.
[Sidenote: The Leipzig Debate, 1519] A debate on this and other propositions between Eck on the one side and Luther and his colleague Carlstadt on the other took place at Leipzig in the days from June 27 to July 16, 1519.

The climax of the argument on the power of popes and councils came when Eck, skilfully manoeuvring to show that Luther's opinions were identical with those of Huss, forced from his opponent the bold declaration that "among the opinions of John Huss and the Bohemians many are certainly most Christian and evangelic, and cannot be condemned by the universal church." The words sent a thrill through the audience and throughout Christendom.

Eck could only reply: "If you believe that a general council, legitimately convoked, can err, you are to me a heathen and a publican." Reconciliation was indeed no longer possible.

When Luther had protested against the abuse of indulgences he did so as a loyal son of the church.