An encyclical is a pastoral letter addressed by the pope to the whole Church. Encyclical letters generally address matters of faith or morals, encourage a particular commemoration or pious devotion, or deal with matters of Church discipline which are to be universally observed.

The apostles used letters to address the faithful of the various churches they had helped to establish. Most notably, St. Paul wrote a number of letters (epistles), 21 of which are included in the canon of the New Testament. Their successors, the bishops, followed this practice and would often send letters to one another and to the members of the particular churches entrusted to their pastoral care in order to ensure consistency in faith and practice, especially with regard to the celebration of the liturgy. The Bishop of Rome himself would write letters to be circulated to all the bishops. He also received letters from the bishops, which he, in turn, would circulate to other bishops.

During the Middle Ages, the practice of sending these letters fell into disuse. During this time, the popes would send letters only to individual bishops about particular matters within their dioceses. Bishops would respond in writing only to the pope.

Pope Benedict XIV (r. 1740-58), wisely employing the power of the newly invented printing press, revived the ancient practice of the pope writing letters to all the bishops of the world. It was Pope Gregory XVI who applied the term “encyclical” to these letters, from the Latin word encyclicus, or circular, because they were addressed to the entire Church. Since 1740, popes have produced nearly 300 encyclical letters, which have addressed any number of issues pertaining to the life and ministry of the Church.

“He Who Hears You, Hears Me”

Encyclical letters are not considered divinely inspired and do not contain matters considered to be new revelation. However, they are regarded as instruments of the ordinary Magisterium containing the authoritative teaching of the Vicar of Christ.

As regards the question of the binding authority of the teaching contained within an encyclical, Pope Pius XII stated the following in his encyclical letter Humani Generis, dated Aug. 12, 1950: “Nor must it be thought that what is contained in an encyclical letter does not of itself demand assent, on the pretext that the popes do not exercise in them the supreme power of their teaching authority. Rather, such teachings belong to the ordinary magisterium, of which it is true to say: ‘He who hears you, hears me’ (Lk 10:16); for the most part, too, what is expounded and indicated in encyclical letters already appertains to Catholic doctrine for other reasons.”

The Second Vatican Council declared: “Religious submission of will and of mind must be shown in a special way to the authentic teaching of the Roman Pontiff, even when he is not speaking ex cathedra. That is, it must be shown in such a way that his supreme magisterium is acknowledged with reverence, the judgments made by him are sincerely adhered to, according to his manifest mind and will. His mind and will in the matter may be known chiefly either from the character of the documents, his frequent repetition of the same doctrine, or from his manner of speaking” (Dogmatic Constitution on the Church, Lumen Gentium, No. 25).

Papal encyclical letters at times have been received by the Church with joy as they have addressed matters of popular piety or devotion. At other times, the popes have written encyclicals addressing matters pertaining to the great moral issues of their time. Such letters have often been the source of much debate among various scholars and theologians.

Encyclicals are not in and of themselves considered to be infallible pronouncements of the pontiff. And while the teachings contained therein may sometimes prove burdensome and difficult for some to accept and to follow, Catholics of good will everywhere are obliged to acknowledge their apostolic authority and strive to humbly assent to their teaching. How blessed the Church has been to receive the teaching of the Lord and the guidance of the Holy Spirit that is contained in the encyclical letters of the popes down through the ages!

Father Joseph L. Parisi received his Master of Pastoral Theology Degree from the University of St. Thomas Aquinas in Rome in 1974 and the Licentiate in Canon Law from the University of St. Paul in Ottawa, Canada, in 1986. 

The Example of Humanae Vitae

Few encyclical letters have been the source of as much controversy or dissent as Humanae Vitae, written by Pope Paul VI, who sought to crystallize the doctrinal teaching enunciated by the council fathers of the Second Vatican Council regarding marriage and family.

On Dec. 7, 1965, Pope Paul VI and the fathers of Vatican II published the Pastoral Constitution on the Church, entitled Gaudium et Spes. The third chapter of that conciliar document speaks at length of the sacred character and dignity of marriage and the family which is its fruit. The same council fathers took the opportunity to restate with great clarity that marriage and conjugal love are intimately ordered by the Creator and by nature itself to the procreation and education of children. They declared that Christian spouses are to bind themselves to the Church’s teaching. They further stated that Christian couples are to be governed by a conscience formed in full conformity with the divine law and the consistent magisterial teachings of the Church, which has been given the charism to interpret authentically the law in light of the Gospel.

It is important to place the pronouncements of Gaudium et Spes within the historical context of its time. Oral contraceptives first appeared in medical practice in 1960. Very soon thereafter, several noteworthy theological voices expressed a desire for the Church to reconsider its position regarding the regulation of birth by artificial means. In 1963, Pope John XXIII established what became a commission of six European scholars (non-theologians) to undertake a sociological study of birth control and population growth. This commission met once in 1963 and twice in 1964. As Vatican II was concluding, Pope Paul expanded this commission, enlarging it to 58 members. Among them were married couples, laywomen, theologians and bishops.

Following the close of Vatican II, a final meeting of the commission, which Pope Paul VI had enlarged to include 16 bishops as an executive committee, took place in 1966. The commission was only consultative, but its controversial final report to Pope Paul was approved by a majority of the membership. In that report, the commission proposed that the pope might use his supreme authority to approve at least some form of artificial contraception for married couples to assist them in their decisions to responsibly limit the size of their families. A minority of members dissented and issued a parallel report to the Pope. After more than two years of study and consultation, Pope Paul issued Humanae Vitae on July 25, 1968.

The pontiff exercised his duty and function as Successor of Peter and Vicar of Christ and issued the encyclical declaring that marriage and the conjugal life are ordered intrinsically to both the good of the spouses and the procreation and education of children. In Humanae Vitae, he removed any doubt that any of the forms of artificial contraceptive, oral hormonal anti-ovulants among them, are not in harmony with the authentic magisterial teaching of the Church and that the Christian faithful were to take care to avoid any act in conflict with that teaching.

In promulgating his encyclical, it is evident that the Pope did not see himself speaking as a private theologian like other theologians, but in virtue of the mandate entrusted to him by Christ himself as His Vicar. Clearly, Pope Paul did not utter his teaching ex cathedra and seek to place upon the instruction the seal of papal infallibility. And yet, in the authentic exercise of his supreme apostolic authority, he proposed anew the consistent truth of God’s unitive plan for marital love and the procreation of life and family.

Humanae Vitae was greeted with much dissent and disagreement. It remains among the most controversial of all papal encyclicals. And yet the authentic teaching of Pope Paul has been affirmed and restated by his successors and has been enshrined in canons of the Catechism of the Catholic Church (see Nos. 2366-2372), and there are many theologians who see the teachings of Pope Paul as remarkably prophetic in their warnings of the impact to society that might result from a contraceptive mentality.