Reply #4: The doctrine of papal infallibility [View All]

<snip>
The First Vatican Council has defined as "a divinely revealed dogma" that "the Roman Pontiff, when he speaks ex cathedra -- that is, when in the exercise of his office as pastor and teacher of all Christians he defines, by virtue of his supreme Apostolic authority, a doctrine of faith or morals to be held by the whole Church -- is, by reason of the Divine assistance promised to him in blessed Peter, possessed of that infallibility with which the Divine Redeemer wished His Church to be endowed in defining doctrines of faith and morals; and consequently that such definitions of the Roman Pontiff are irreformable of their own nature (ex sese) and not by reason of the Church's consent" --Infallibility at the Catholic Encyclopedia <1913> <snip>

http://www.zpub.com/un/pope/infal.html

Hard to win an argument against someone with this kind of power. ;)