Magisterium

The magisterium of the Catholic Church is the church's authority or office to establish its own authentic teachings. That authority is vested uniquely by the pope and by the bishops, under the premise that they are in communion with the correct and true teachings of the faith.Sacred scripture and sacred tradition "make up a single sacred deposit of the Word of God, which is entrusted to the Church", and the magisterium is not independent of this, since "all that it proposes for belief as being divinely revealed is derived from this single deposit of faith."

The exercise of the Catholic Church's magisterium is sometimes, but only rarely, expressed in the solemn form of an ex cathedra papal declaration, "when, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, [the Bishop of Rome] defines a doctrine concerning faith or morals to be held by the whole Church", or of a similar declaration by an ecumenical council. Such solemn declarations of the church's teaching involve the infallibility of the Church.

Pope Pius IX's definition of the Immaculate Conception of Mary and Pope Pius XII's definition of the Assumption of Mary are examples of such solemn papal pronouncements, but are the only two to ever have been granted. Most dogmas have been promulgated at ecumenical councils. Examples of solemn declarations by ecumenical councils are the Council of Trent's decree on justification and the First Vatican Council's definition of papal infallibility.

The Catholic Church's magisterium is exercised without this solemnity in statements by popes and bishops, whether collectively (as by an episcopal conference) or singly, in written documents such as catechisms, encyclicals and pastoral letters, or orally, as in homilies. These statements are part of the ordinary magisterium of the church.

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