Chapter 4. On the infallible teaching
authority of the Roman pontiff
1. That apostolic primacy which the
Roman pontiff possesses as successor of Peter, the prince of the apostles,
includes also the supreme power of teaching.
This holy see has always maintained this,
the constant custom of the church demonstrates it, and
the ecumenical councils, particularly those in which East and
West met in the union of faith and charity, have declared it.
the fathers of the fourth council of Constantinople, following the
footsteps of their predecessors, published this solemn profession of
What is more, with the approval
of the second council of Lyons, the Greeks made the following profession:
Then there is the definition of
the council of Florence:
satisfy this pastoral office, our predecessors strove unwearyingly that
the saving teaching of Christ should be spread among all the peoples of
the world; and with equal care they made sure that it should be kept pure
and uncontaminated wherever it was received.
was for this reason that the bishops of the whole world, sometimes
individually, sometimes gathered in synods, according to the long
established custom of the churches and the pattern of ancient usage
referred to this apostolic see those dangers especially which arose in
matters concerning the faith. This was to ensure that any damage suffered
by the faith should be repaired in that place above all where the faith
can know no failing59.
Roman pontiffs, too, as the circumstances of the time or the state of
the holy Spirit was promised to the successors of Peter
Indeed, their apostolic teaching
for they knew very well that this
see of St. Peter always remains unblemished by any error, in accordance with
the divine promise of our Lord and Saviour to the prince of his disciples: I
have prayed for you that your faith may not fail; and when you have turned
again, strengthen your brethren60.
gift of truth and never-failing faith was therefore divinely conferred on
Peter and his successors in this see so that they might discharge their
exalted office for the salvation of all, and so that the whole flock of
Christ might be kept away by them from the poisonous food of error and be
nourished with the sustenance of heavenly doctrine. Thus the tendency to
schism is removed and the whole church is preserved in unity, and, resting
on its foundation, can stand firm against the gates of hell.
since in this very age when the salutary effectiveness of the apostolic
office is most especially needed, not a few are to be found who disparage
its authority, we judge it absolutely necessary to affirm solemnly the
prerogative which the only-begotten Son of God was pleased to attach to
the supreme pastoral office.
the exercise of his office as shepherd and teacher of all Christians,
virtue of his supreme apostolic authority,
defines a doctrine concerning faith or morals to be held by the whole
infallibility which the divine Redeemer willed his church to enjoy in
defining doctrine concerning faith or morals.
such definitions of the Roman pontiff are of themselves, and not by the
consent of the church, irreformable.
10. So then, should anyone, which God forbid, have the
temerity to reject this definition of ours: let him be anathema.