Session 4 :
18 July 1870
constitution on the Church of Christ
Pius, bishop, servant of the servants of God, with the approval of the
Sacred Council, for an everlasting record.
1. The eternal shepherd and guardian of our souls , in order to
render permanent the saving work of redemption, determined to build a
Church in which, as in the house of the living God, all the faithful
should be linked by the bond of one faith and charity.
2. Therefore, before he was glorified, he besought his Father, not for
the apostles only, but also for those who were to believe in him
through their word, that they all might be one as the Son himself and
the Father are one .
3. So then, just as he sent apostles, whom he chose out of the world
, even as he had been sent by the Father , in like manner it
was his will that in his Church there should be shepherds and teachers
until the end of time.
4. In order, then, that the episcopal office should be one and
undivided and that, by the union of the clergy, the whole multitude of
believers should be held together in the unity of faith and communion,
he set blessed Peter over the rest of the apostles and instituted in
him the permanent principle of both unities and their visible
5. Upon the strength of this foundation was to be built the eternal
temple, and the Church whose topmost part reaches heaven was to rise
upon the firmness of this foundation .
6. And since the gates of hell trying, if they can, to overthrow the
Church, make their assault with a hatred that increases day by day
against its divinely laid foundation, we judge it necessary, with the
approbation of the Sacred Council, and for the protection, defense and
growth of the Catholic flock, to propound the doctrine concerning the
1. institution, 2. permanence and 3. nature of the sacred and apostolic
primacy, upon which the strength and coherence of the whole Church
7. This doctrine is to be believed and held by all the faithful in
accordance with the ancient and unchanging faith of the whole Church.
8. Furthermore, we shall proscribe and condemn the contrary errors
which are so harmful to the Lord's flock.
On the institution of the apostolic primacy in blessed Peter
1. We teach and declare that, according to the gospel evidence, a
primacy of jurisdiction over the whole Church of God was immediately
and directly promised to the blessed apostle Peter and conferred on him
by Christ the lord.
2. It was to Simon alone, to whom he had already said You shall be
called Cephas , that the Lord, after his confession, You are the
Christ, the son of the living God, spoke these words:
Blessed are you, Simon Bar-Jona. For flesh and blood has not revealed
this to you, but my Father who is in heaven. And I tell you, you are
Peter, and on this rock I will build my Church, and the gates of the
underworld shall not prevail against it. I will give you the keys of
the kingdom of heaven, and whatever you bind on earth shall be bound in
heaven, and whatever you loose on earth shall be loosed in heaven  .
3. And it was to Peter alone that Jesus, after his resurrection,
confided the jurisdiction of Supreme Pastor and ruler of his whole
fold, saying: Feed my lambs, feed my sheep .
4. To this absolutely manifest teaching of the Sacred Scriptures, as it
has always been understood by the Catholic Church, are clearly opposed
the distorted opinions of those who misrepresent the form of government
which Christ the lord established in his Church and deny that Peter, in
preference to the rest of the apostles, taken singly or collectively,
was endowed by Christ with a true and proper primacy of jurisdiction.
5. The same may be said of those who assert that this primacy was not
conferred immediately and directly on blessed Peter himself, but rather
on the Church, and that it was through the Church that it was
transmitted to him in his capacity as her minister.
6. Therefore, if anyone says that blessed Peter the apostle was not
appointed by Christ the lord as prince of all the apostles and visible
head of the whole Church militant; or that it was a primacy of honor
only and not one of true and proper jurisdiction that he directly and
immediately received from our lord Jesus Christ himself: let him be
On the permanence of the primacy of blessed Peter in the Roman pontiffs
1. That which our lord Jesus Christ, the prince of shepherds and great
shepherd of the sheep, established in the blessed apostle Peter, for
the continual salvation and permanent benefit of the Church, must of
necessity remain for ever, by Christ's authority, in the Church which,
founded as it is upon a rock, will stand firm until the end of time
2. For no one can be in doubt, indeed it was known in every age that
the holy and most blessed Peter, prince and head of the apostles, the
pillar of faith and the foundation of the Catholic Church, received the
keys of the kingdom from our lord Jesus Christ, the savior and redeemer
of the human race, and that to this day and for ever he lives and
presides and exercises judgment in his successors the bishops of the
Holy Roman See, which he founded and consecrated with his blood .
3. Therefore whoever succeeds to the chair of Peter obtains by the
institution of Christ himself, the primacy of Peter over the whole
Church. So what the truth has ordained stands firm, and blessed Peter
perseveres in the rock-like strength he was granted, and does not
abandon that guidance of the Church which he once received .
4. For this reason it has always been necessary for every Church--that
is to say the faithful throughout the world--to be in agreement with
the Roman Church because of its more effective leadership. In
consequence of being joined, as members to head, with that see, from
which the rights of sacred communion flow to all, they will grow
together into the structure of a single body .
5. Therefore, if anyone says that it is not by the institution of
Christ the lord himself (that is to say, by divine law) that blessed
Peter should have perpetual successors in the primacy over the whole
Church; or that the Roman Pontiff is not the successor of blessed Peter
in this primacy: let him be anathema.
On the power and character of the primacy of the Roman Pontiff
1. And so, supported by the clear witness of Holy Scripture, and
adhering to the manifest and explicit decrees both of our predecessors
the Roman Pontiffs and of general councils, we promulgate anew the
definition of the ecumenical Council of Florence , which must be
believed by all faithful Christians, namely that the Apostolic See and
the Roman Pontiff hold a world-wide primacy, and that the Roman Pontiff
is the successor of blessed Peter, the prince of the apostles, true
vicar of Christ, head of the whole Church and father and teacher of all
To him, in blessed Peter, full power has been given by our lord Jesus
Christ to tend, rule and govern the universal Church.
All this is to be found in the acts of the ecumenical councils and the
2. Wherefore we teach and declare that, by divine ordinance, the Roman
Church possesses a pre-eminence of ordinary power over every other
Church, and that this jurisdictional power of the Roman Pontiff is both
episcopal and immediate. Both clergy and faithful, of whatever rite and
dignity, both singly and collectively, are bound to submit to this
power by the duty of hierarchical subordination and true obedience, and
this not only in matters concerning faith and morals, but also in those
which regard the discipline and government of the Church throughout the
3. In this way, by unity with the Roman Pontiff in communion and in
profession of the same faith , the Church of Christ becomes one flock
under one Supreme Shepherd .
4. This is the teaching of the Catholic truth, and no one can depart
from it without endangering his faith and salvation.
5. This power of the Supreme Pontiff by no means detracts from that
ordinary and immediate power of episcopal jurisdiction, by which
bishops, who have succeeded to the place of the apostles by appointment
of the Holy Spirit, tend and govern individually the particular flocks
which have been assigned to them. On the contrary, this power of theirs
is asserted, supported and defended by the Supreme and Universal
Pastor; for St. Gregory the Great says: "My honor is the honor of the
whole Church. My honor is the steadfast strength of my brethren. Then
do I receive true honor, when it is denied to none of those to whom
honor is due." 
6. Furthermore, it follows from that supreme power which the Roman
Pontiff has in governing the whole Church, that he has the right, in
the performance of this office of his, to communicate freely with the
pastors and flocks of the entire Church, so that they may be taught and
guided by him in the way of salvation.
7. And therefore we condemn and reject the opinions of those who hold
that this communication of the Supreme Head with pastors and flocks may
be lawfully obstructed; or that it should be dependent on the civil
power, which leads them to maintain that what is determined by the
Apostolic See or by its authority concerning the government of the
Church, has no force or effect unless it is confirmed by the agreement
of the civil authority.
8. Since the Roman Pontiff, by the divine right of the apostolic
primacy, governs the whole Church, we likewise teach and declare that
he is the supreme judge of the faithful , and that in all cases
which fall under ecclesiastical jurisdiction recourse may be had to his
judgment . The sentence of the Apostolic See (than which there is
no higher authority) is not subject to revision by anyone, nor may
anyone lawfully pass judgment thereupon . And so they stray from
the genuine path of truth who maintain that it is lawful to appeal from
the judgments of the Roman pontiffs to an ecumenical council as if this
were an authority superior to the Roman Pontiff.
9. So, then, if anyone says that the Roman Pontiff has merely an office
of supervision and guidance, and not the full and supreme power of
jurisdiction over the whole Church, and this not only in matters of
faith and morals, but also in those which concern the discipline and
government of the Church dispersed throughout the whole world; or that
he has only the principal part, but not the absolute fullness, of this
supreme power; or that this power of his is not ordinary and immediate
both over all and each of the Churches and over all and each of the
pastors and faithful: let him be anathema.
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.
2. So the fathers of the fourth Council of Constantinople, following
the footsteps of their predecessors, published this solemn profession
of faith: The first condition of salvation is to maintain the rule of
the true faith. And since that saying of our lord Jesus Christ, You are
Peter, and upon this rock I will build my Church , cannot fail of
its effect, the words spoken are confirmed by their consequences. For
in the Apostolic See the Catholic religion has always been preserved
unblemished, and sacred doctrine been held in honor. Since it is our
earnest desire to be in no way separated from this faith and doctrine,
we hope that we may deserve to remain in that one communion which the
Apostolic See preaches, for in it is the whole and true strength of the
Christian religion .
What is more, with the approval of the second Council of Lyons, the
Greeks made the following profession:
"The Holy Roman Church possesses the supreme and full primacy and
principality over the whole Catholic Church. She truly and humbly
acknowledges that she received this from the Lord himself in blessed
Peter, the prince and chief of the apostles, whose successor the Roman
Pontiff is, together with the fullness of power. And since before all
others she has the duty of defending the truth of the faith, so if any
questions arise concerning the faith, it is by her judgment that they
must be settled." 
Then there is the definition of the Council of Florence: "The Roman
Pontiff is the true vicar of Christ, the head of the whole Church and
the father and teacher of all Christians; and to him was committed in
blessed Peter, by our lord Jesus Christ, the full power of tending,
ruling and governing the whole Church." 
3. To 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.
4. It 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 failing .
5. The Roman pontiffs, too, as the circumstances of the time or the
state of affairs suggested, sometimes by summoning ecumenical councils
or consulting the opinion of the Churches scattered throughout the
world, sometimes by special synods, sometimes by taking advantage of
other useful means afforded by divine providence, defined as doctrines
to be held those things which, by God's help, they knew to be in
keeping with Sacred Scripture and the apostolic traditions.
6. For the Holy Spirit was promised to the successors of Peter not so
that they might, by his revelation, make known some new doctrine, but
that, by his assistance, they might religiously guard and faithfully
expound the revelation or deposit of faith transmitted by the apostles.
Indeed, their apostolic teaching was embraced by all the venerable
fathers and reverenced and followed by all the holy orthodox doctors,
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 Savior 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 brethren .
7. This 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.
8. But 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.
9. Therefore, faithfully adhering to the tradition received from the
beginning of the Christian faith, to the glory of God our savior, for
the exaltation of the Catholic religion and for the salvation of the
Christian people, with the approval of the Sacred Council, we teach and
define as a divinely revealed dogma that when the Roman Pontiff speaks
EX CATHEDRA, that is, when, in the exercise of his office as shepherd
and teacher of all Christians, in virtue of his supreme apostolic
authority, he defines a doctrine concerning faith or morals to be held
by the whole Church, he possesses, by the divine assistance promised to
him in blessed Peter, that infallibility which the divine Redeemer
willed his Church to enjoy in defining doctrine concerning faith or
morals. Therefore, such definitions of the Roman Pontiff are of
themselves, and not by the consent of the Church, irreformable.
So then, should anyone, which God forbid, have the temerity to reject
this definition of ours: let him be anathema.
Given at Rome in public session, solemnly held in the Vatican Basilica
in the year of our Lord one thousand eight hundred and seventy, on the
eighteenth day of July, in the twenty-fifth year of Our Pontificate.
In conformity with the original.
Joseph, Bishop of St. Polten Secretary to the Vatican Council
37 1 Pt 2,25.
38 Jn 17, 20-21.
39 Jn 15, 19.
40 Jn 20, 21.
41 Leo 1, Serm. (Sermons), 4 (elsewhere 3), ch. 2 for the day of his
birth (PL 54, 150).
42 Jn 1, 42.
43 Mt 16, 16 19.
44 Jn 21, 15-17.
45 See Mt 7, 25; Lk 6, 48.
46 From the speech of Philip, the Roman legate, at the 3rd session of
the Council of Ephesus (D no. 112).
47 Leo I, Serm. (Sermons), 3 (elsewhere 2), ch. 3 (PL 54, 146).
48 Irenaeus, Adv. haeres. (Against Heresies) 1113 (PG 7, 849), Council
of Aquilea (381), to be found among: Ambrose, Epistolae (Letters), 11
(PL 16, 946).
49 Council of Florence, session 6 (see above p. 528).
50 See Jn 10, 16.
51 Ep. ad Eulog. Alexandrin. (Letter to Eulogius of Alexandria), VIII
29 (30) (MGH, Ep. 2, 31 28-30, PL 77, 933).
52 Pius VI, Letter Super soliditate dated 28 Nov. 1786.
53 From Michael Palaeologus's profession of faith which was read out at
the second Council of Lyons (D no. 466).
54 Nicholas I, Ep. ad Michaelem imp. (Letter to the emperor Michael)
(PL 119, 954).
55 Mt 16, 18.
56 From Pope Hormisdas's formula of the year 517 (D no. 171), see above
p. 157 n. 1.
57 From Michael Palaeologus's profession of faith which was read out at
the second Council of Lyons (D no. 466).
58 Council of Florence, session 6 (see above p. 528). S Bernard, Ep.
(Letters) 190 (PL 182, 1053).
59 Bernard, Ep. (Letters) 190 (PL 182, 1053).
60 Lk 22, 32.