The Types of Papal Documents and Weight of Each

Many non-Catholics falsely believe that everything the Pope states, even orally, is infallible. It should be obvious that this is not the case. (Think: the February 18, 2016 in-flight press conference on the papal plane, in which the use of contraceptives was purported to be “acceptable in difficult situations.”) Many Catholics likewise falsely believe that everything the Pope writes is preserved from error and must need be followed. This too is not the case. It is worth reflecting on the different types of papal documents that exist and the magisterial weight of each.

Different Types of Papal Documents

Encyclicals: An encyclical is one of the most common types of papal documents. It is a letter sent by the Pope to the bishops of the Church and, through them, to the faithful and sometimes even to all people. Encyclicals usually address doctrinal, moral, or social issues and provide guidance and teaching on matters of faith and morals. They are meant to be read and studied by the faithful to gain a deeper understanding of the Church’s stance on particular topics.

Apostolic Constitutions: An apostolic constitution is a high-level papal document that typically deals with matters related to the governance and structure of the Church. It can establish or modify laws, regulations, or institutions within the Church. Apostolic constitutions are considered to have a higher level of authority than most other types of papal documents.

Motu Proprios: The Latin term “motu proprio” means “on his own initiative”. A motu proprio is a document issued directly by the Pope on his own initiative, without any external prompting. These documents are often used to address specific administrative or disciplinary matters within the Church. Motu proprios can also be used to modify certain aspects of Canon Law or establish new norms.

Bulls: A bull is a papal document that is traditionally sealed with a circular leaden or wax seal, known as a “bulla.” Bulls are used for various purposes, including the establishment of new dioceses, canonization of saints, granting of privileges to individuals or institutions, and other significant administrative actions.

Apostolic Letters: Apostolic letters are personal letters issued by the Pope to individuals, groups, or institutions. While they may not have the same level of authority as encyclicals or apostolic constitutions, they still carry significant weight and often address important pastoral or administrative matters.

Apostolic Exhortations: Apostolic exhortations are documents that encourage the faithful to live out their faith more fully or address specific pastoral challenges. While they are not considered to be as authoritative as encyclicals or apostolic constitutions, they serve as important guides for the faithful in their spiritual lives.

Each of these papal documents plays a crucial role in the communication and governance of the Catholic Church, and they are issued based on the particular context and needs of the Church and its members.

Which Papal Documents Are Infallible?

It is important to remember that no Church document is automatically considered to have the highest possible magisterial weight just because it was issued by the Pope. In fact, infallibility is not automatically associated with any of the above types of documents. As a reminder, the dogma of Papal infallibility asserts that the Holy Father, when speaking ex cathedra (literally, from the chair of Peter), is preserved from error by the Holy Ghost. This solemn manner of speaking is not tied to any particular vehicle of dissemination.

Rather, Blessed Pope Pius IX, in his solemn definition of the Catholic dogma of papal infallibility (in 1870, during the First Vatican Council), explained that an ex cathedra pronouncement has four internal characteristics:

“[T]he Roman Pontiff … speaks ex cathedra … when, acting in the office of shepherd and teacher of all Christians, he defines, by virtue of his supreme apostolic authority, doctrine concerning faith or morals to be held by the universal Church.”

Necessary Conditions

We could list those four characteristics of an infallible “ex cathedra” Papal teaching in the following way:

  • The Pope must be exercising his role as the supreme ruler, teacher, and judge of the universal Church – not simply as a private theologian, or even as the head of a Roman Congregation or tribunal. There are formulas the Popes use to clearly express this, including phrases such as: “By Our authority as teacher of all Christians,” “By the authority of Christ,” or “By the authority of St. Peter and St. Paul.”
  • The Pope must be pronouncing on a matter of faith or morals, not on practical or disciplinary matters. No guessing or debate is needed to know if this criteria has been met. The Pope himself must state this is a matter of faith (doctrine) or morals if he wants it to be accepted as infallible teaching.
  • The Pope must make clear a voluntas definiendi, his intention to define a doctrine. Catholics are obligated to assent to infallible teaching. Therefore, the specific doctrine which requires assent must be clearly defined. If there is no definition given, then it is not possible for infallibility to apply.
  • The Pope must make clear that all Catholics throughout the world and for all future ages are bound in conscience to this teaching. If the Pope gives a doctrine or rule only to bishops or only to Italians, then it is not universal and can’t have infallible authority.

A fifth condition which many people fail to mention is that the Pope is not permitted to “invent” a new or novel doctrine with infallible power. Vatican I clearly states: “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.”[1]

Therefore, when the Pope issues an infallible teaching, he also goes through great lengths to show how that teaching is contained in Sacred Scripture and Sacred Tradition.

Examples of Infallibility

Infallible pronouncements by the Pope are extremely rare. The most well-known instances in recent times were the definition of the dogma of the Immaculate Conception and the dogma of the Assumption of Our Lady, in 1854 and 1950, respectively. If you read these documents, you will see what effort the Popes made to show how these two teachings are from Divine Revelation and found in both Scripture and Tradition.

The dogma of the Immaculate Conception of the Blessed Virgin Mary was defined through an apostolic constitution. The document that defined this dogma is called Ineffabilis Deus, and it was issued by Pope Pius IX on December 8, 1854. In this apostolic constitution, Pope Pius IX declared and defined as a dogma that the Blessed Virgin Mary, by a singular privilege granted Her by God, was preserved from any stain of original sin from the first moment of Her conception in the womb of St. Anne.

The dogma of the Assumption of the Blessed Virgin Mary was also defined through an apostolic constitution. The document that defined this dogma is called Munificentissimus Deus, and it was promulgated by Pope Pius XII on November 1, 1950. In this apostolic constitution, Pope Pius XII proclaimed the dogma of the Assumption, which states that the Blessed Virgin Mary, at the end of Her earthly life, was assumed body and soul into heavenly glory.

But these examples do not mean that all apostolic constitutions are infallible. An example of an apostolic constitution that did not define anything infallible is the apostolic constitution Veterum Sapientia. It was promulgated on February 22, 1962, and it addresses the importance, and need for preservation, of Latin as the language of the Catholic Church’s liturgy, theology, and educational institutions. In Veterum Sapientia, Pope John XXIII emphasized the enduring value and rich tradition of Latin within the Church. While the document is authoritative and reflects the Pope’s teaching on the subject, it does not involve a definitive definition of a dogma or a statement of infallible doctrine. Instead, it falls under the category of pastoral teaching and encouragement regarding the use of Latin in the life of the Church.


Encyclicals, apostolic constitutions, motu proprios, and other papal documents are not automatically infallible. Their authority varies based on the level of teaching and the manner in which they are promulgated. It is possible for them to contain error, and finding errors in such a document should never scandalize to doubting any point of infallible Catholic dogma.

Infallibility is a special and restricted aspect of the Pope’s extraordinary magisterium within the broader context of his teaching role in the Church. We should nevertheless spend time reading and studying the traditional documents issued by Popes in the past before the doctrinal uncertainty that emerged full force in the mid-1960s.


[1] Pastor Aeternus, Dogmatic Constitution on the Church of Christ, July 18, 1870, Chapter 4, No. 6.