Catholic Medical Quarterly

The Journal of the Catholic Medical Association (UK)

Building knowledge. Building faith. Protecting the vulnerable.

Catholic Medical Quarterly Volume 62(4) November 2012

The infallible teaching of Humanae Vitae

By Fr Thomas Crean O.P

Editorial note.
At its promulgation, many were told that Humanae Vitae belongs to the ordinary Magisterium of the Catholic Church. Many have taken this to mean that it is not an infallible document.

In the following article, the author argues otherwise.

Cover of Humanae VitaeThe encyclical letter Humanae Vitae, promulgated by Pope Paul VI in 1968, is certainly one of the most important Church documents of modern times. The Pope was addressing a question of great relevance for millions of married couples, namely, what the natural moral law permits and forbids with regard to regulating procreation. Already in 1930, Pope Pius XI had restated the perennial teaching of the Church concerning contraception in his letter Casti Connubii, wherein he noted that “any use whatsoever of matrimony exercised in such a way that the act is deliberately frustrated in its natural power to generate life is an offense against the law of God and of nature” (para. 56). The advent of the contraceptive pill, however, had raised an apparently new question, prompting speculation among some Catholics that this method of regulating procreation might be morally permissible. In accord with his duty as shepherd of Christ’s flock, Pope Paul VI carefully pondered this question and gave his response in his encyclical on 25th July, 1968. He taught that married couples must avoid “every action which, either in anticipation of the conjugal act, or in its accomplishment, or in the development of its natural consequences, proposes, whether as an end or as a means, to render procreation impossible” (para. 14). In other words, the contraceptive pill may not be used. The Pope also made it clear that this prohibition was not simply a law of the Church, applying only to Catholics, but part of the immutable moral law, applying to all mankind. He explained that for the spouses to make the conjugal act deliberately infertile is “intrinsically disordered, and hence unworthy of the human person” (ibid.).

The authority of encyclicals

What is the authority of this teaching? People sometimes suppose that because papal encyclicals rarely use the dramatic language associated with, for example, the solemn definitions of the Immaculate Conception and the Assumption, they must therefore belong to what is called ‘non-infallible teaching’; teaching which could conceivably be in error, however unlikely this may be. When a bishop writes a pastoral letter to his diocese about, say, the mystery of the Trinity, it is unlikely that it will contain errors, both because of the learning which he may be presumed to possess and because of the light which is given him by the Holy Spirit to accomplish his duties; but it is not impossible that it could contain erroneous statements about the Trinity which might later need to be corrected. Was Pope Paul’s teaching about contraception also of this kind?

In an article published in 1949, the American theologian Joseph Fenton explained that it is an error to suppose that papal encyclicals cannot contain infallible, or as it is also called, ex cathedra teaching. The first Vatican Council solemnly defined that the Pope speaks infallibly ‘whenever, performing his task as shepherd and teacher of all Christians, he defines with his supreme apostolic authority a doctrine concerning faith or morals, to be held by the whole Church’. As Fenton notes, the Pope can indeed meet these conditions for infallibility when writing an encyclical. In the first place, the very fact that an encyclical is addressed to all the bishops of the world sufficiently shows that the Pope is addressing the whole Church. Again, it is quite possible for a Pope to ‘define’ doctrine in the course of an encyclical. A ‘definition’, Fenton explains, is simply “an ultimate and irrevocable doctrinal decision”. It does not need to be introduced by some special forms of words such as ‘We declare and define’. Nor does it need to be accompanied by a warning that the contrary opinion is heretical, or by the announcement of penalties for those who are contumacious.

Fenton’s explanation of the word ‘definition’ accords with a far higher authority, that of Vatican I itself. The relator of that Council, that is, the man charged with explaining to the assembled bishops the precise meaning of the texts that they were voting on, described what is meant by ‘defining’ a doctrine in these terms:-

“The word ‘defines’ signifies that the Pope directly and conclusively pronounces his judgement about a doctrine which concerns matters of faith or morals, and that he does so in such a way that each one of the faithful can be certain of the mind of the Roman Pontiff.”

Humanæ Vitæ and Vatican I

To return to Humanae Vitae. Does its teaching on contraception pill fulfil the four conditions that Vatican I laid down for a papal teaching to be infallible? We can consider them in turn.

  1. The Pope must be exercising his office of ‘shepherd and teacher of all Christians’, not, for example, giving a Sunday sermon or a lecture to theological students. Humanae Vitae meets this condition and even goes beyond it. Pope Paul addresses his encyclical to “the Venerable Patriarchs, Archbishops, Bishops and other local Ordinaries in peace and communion with the Apostolic See, to priests, the faithful and all men of good will”. Pope Paul was acting as universal shepherd, just as Christ had said to St Peter, without any limitation, ‘Feed my sheep’ (Jn. 21:17).
  2. He must be ‘defining a doctrine with his supreme apostolic authority’. He must not, in other words, be proposing a doctrine as merely probably true or as simply safe to follow. As the Relator explained at Vatican I, to define a doctrine the Pope must, using the authority that he alone of mortal men possesses, “directly and conclusively pronounce his judgement... in such a way that each one of the faithful can be certain” of his meaning. In Humanae Vitae¸ Pope Paul explicitly invoked his apostolic authority. “After mature reflection and assiduous prayers”, he wrote, “We now intend, by virtue of the mandate entrusted to us by Christ, to give our reply to these grave questions” (para. 6). He also gave his reply ‘directly and conclusively’: all forms of abortion, sterilization and contraception are to be ‘wholly rejected’ as ‘intrinsically wrong’, and whoever disagrees is ‘entirely mistaken’ (para. 14). Surely, no one who reads Humanæ Vitæ need be in any doubt as to ‘the mind of the Roman pontiff’.
  3. The Pope must be speaking about a matter of faith or morals, and not, for example, giving his opinion about literature or secular history. This condition is obviously fulfilled by Humanae Vitae, which gave a teaching on the morality of contraception.
  4. He must intend that his teaching be accepted as true by the whole Church. This condition is barely separable from the first two, since if the Pope is acting as supreme pastor and delivering a definitive judgement, he can hardly wish that his teaching should not be accepted. But Pope Paul did explicitly remind Christians of the duty to accept his teaching. To married people, he wrote, “Let married couples, then, face up to the efforts needed, supported by the faith and hope which do not disappoint . . . let them implore divine assistance by persevering prayer; above all, let them draw from the source of grace and charity in the Eucharist.’ (para. 25). To priests, he wrote, “Be the first to give, in the exercise of your ministry, the example of loyal internal and external obedience to the teaching authority of the Church” (para. 28). To his brother bishops: “At the head of the priests, your collaborators, and of your faithful, work ardently and incessantly for the safeguarding and the holiness of marriage, so that it may always be lived in its entire human and Christian fullness.” Pope Paul wished that his clear and definite teaching be embraced by all the faithful.


Christ founded a Church to show us the way to heaven and promised to remain with it always. If the Catholic Church is what Christ said that it would be, it must be able to give its members clear and certain teaching

The teaching of Humanae Vitae on contraception meets the criteria for infallibility. We need not be surprised by this. Christ founded a Church to show us the way to heaven and promised to remain with it always. If the Catholic Church is what Christ said that it would be, it must be able to give its members clear and certain teaching about what kinds of action are displeasing to God. In regard to a question such as that of contraception, which touches so many people and touches them so intimately, we should not suppose that Christ, the good Shepherd, would leave His people without this sure guidance. Pope Paul’s teaching has since been repeated by his successors, John Paul II and Benedict XVI. The purpose of this article is to show that even by itself, Humanae Vitae gives a teaching which cannot be revised and will remain true for all time. And Jesus answering said to him, ‘Whatever thou shalt bind on earth, shall be bound also in heaven’. box here Christ founded a Church to show us the way to heaven and promised to remain with it always. If the Catholic Church is what Christ said that it would be, it must be able to give its members clear and certain teaching