There is little left to be said about Humanae vitae. This is not because it is not a rich and fruitful document. It is, of course. Indeed, it is the foundation of the Church’s entire moral position in the modern age. When Paul refused to open the door to birth control, he provided the conceptual framework for John Paul to keep the door barred against abortion and euthanasia. He also provided the orientation toward human life that one finds in Francis’s Laudato si’. On the other hand, no other papal pronouncement has been as controversial the world over as Humanae vitae. It has been cheered and lamented by Catholics and non-Catholics alike. Yet it is the fiftieth anniversary of Humanae vitae, and the occasion does, we think, call for a few words.

Foremost among them is the recognition of the fact that we have discussed before. 2018 is the year of Paul VI. We have seen the fiftieth anniversary of the Credo of the People of God, we are marking the fiftieth anniversary of Humanae vitae, and this fall, we shall see him raised to the altars as Saint Paul VI. But the influence of Paul VI in this time extends far beyond some anniversaries and a canonization. There is a sense that the Church has been plunged, since 2013, into some of the debates that raged under Paul VI. After the pause presented by John Paul II and Benedict XVI—and the collapse of the consensus that those popes represented—the dialectic within the Church between tradition and modernity (and, frankly, modernism) has resumed.

We have commented, we think, elsewhere about Gladden Pappin’s argument (following Baudrillard) that, following the pause from 1991 to 2001, history has resumed. Perhaps there is something to be said for this in terms of world history. But it seems clear that, regardless of what has happened in the world at large, history has resumed in the Church. It is natural, therefore, to look back to Paul VI in these times. Paul VI was the last pope to confront—and be forced to judge—the conflict between tradition and modernity. And Humanae vitae is the premier example of Paul confronting and deciding such a conflict. The lessons of Paul’s act of frankly Apostolic courage and clarity still deserve to be considered, along with the other lessons to be drawn from Paul’s complex, often frustrating papacy.

In Humanae vitae, we find the germ of the basic liberal narrative of the Church. After the Council, all things were possible and it looked like the Church was going to enter modernity enthusiastically. Innovations that were opposed fiercely by Pius XII in Humani generis looked tame in comparison to what burst onto the scene after 1965. Then Pope Paul, with a voice that seemed to come from an earlier time, clearly and unambiguously opposed one of the most cherished practices of modern liberalism. Things started to go wrong. For the liberals, 1968 to 2013 was an unmitigated stream of disasters and disappointments. (This is not quite right, but close enough for our purposes.) Ever since Humanae vitae, there is a sense of having lost what could have been. And this sense has become especially acute since Francis’s election.

The story of Humanae vitae is well known by now. Paul set up a commission to study birth control. The bishops and theologians came down almost unanimously in favor of permitting, at least in some circumstances, birth control. It was widely expected—and a draft of an encyclical prepared, if we remember right—that Paul would ratify the decision of the commission. However, the towering prefect of the Holy Office, Alfredo Cardinal Ottaviani, and a handful of others (no doubt, in the standard liberal telling of the story, identified as reactionaries), opposed such an opening. They were able to convince Paul to go against the experts on the commission and reject any opening to birth control. Yet, according to the liberals, this teaching has not been received by the faithful, who contracept in roughly the same proportion as the faithful of the third century professed that the Son was of like substance as the Father, and some future enlightened pope is expected to come and set things straight.

We have mused before whether the deliberations leading to Humanae vitae were on Paul’s mind when he proclaimed his great Credo of the People of God. The basic narrative is, of course, that Paul was dismayed by the Dutch Catechism and other errors and enormities seemingly receiving approval from the hierarchy. He decided, therefore, to confirm his brethren in the Apostolic faith handed down from Peter to Paul VI. Yet we cannot shake the sense that Paul’s creed and Humanae vitae are of a piece. To say that the Paul of Humanae vitae is separate from the Paul of the creed would be to separate him from himself. One reads about Paul’s agonies of conscience during the explosive period following the Council, but one does not read that Paul was unmoored altogether.

We see then that Paul understood acutely the essence of the Petrine ministry. The pope acts as the guardian of the unity of the faith. His refusal to bend to the spirit of the age must be seen as an act touching upon the very essence of the papacy. Over the past five years, especially in the context over the debate of Amoris laetitia, we have had opportunity to read much (and write some) about the vision of the papacy in Pastor aeternus, the First Vatican Council’s great dogmatic decree about the Petrine office. The pope receives the assistance of the Holy Spirit not so that he can propose new doctrines—after all, public revelation ceased with the death of the last apostle—but so that he can guard the faith definitively. To condemn error is, therefore, at the heart of the Petrine office.

In this regard, Paul had for his example Pius XI and his encyclical, Casti connubii. In that document, which may be read as a rejoinder to the Anglicans’ collapse and acceptance of contraception at the 1930 Lambeth Conference, Pius condemned contraception in ringing terms. Terms, in fact, that have been argued invoked the extraordinary magisterium. Indeed, we know because the working papers of Paul’s commission to examine birth control were leaked at the time to try to create pressure on the pope that the irreformability of Casti connubii was hotly debated in the commission. However, it appears that Pius XI and Casti connubii weighed heavily on Paul’s mind.

The pope’s role as guarantor of the unity of faith would be undercut severely if a pope were, per impossibile, to overturn a clear ruling by one of his predecessors in a matter touching upon faith and morals. Once such a thing happened, the rule of faith would be at the mercy of the reigning pope. After all, what one pope does, another pope can undo. Whether or not Paul articulated that sense, we do not know. However, by reaffirming Pius’s clear condemnation of contraception, whether Casti connubii was technically infallible or not, Paul revealed his knowledge of the deeper truth about the papacy.

This was understood, we think, by his contemporaries. The Jesuit-run AARP Magazine supplement, America, has relived its glory days by posting some of its contemporary content about Humanae vitae. One of its early editorials responds to Humanae vitae by placing dissenters in dialogue with Paul himself. Paul’s teaching was not a teaching, according to the editors, but merely one opinion among many, based on reasoning subject to critique. It was, we see, anything except an Apostolic utterance, drawing its authority from Christ’s command to Peter to teach all nations. In other words, the critics of Humanae vitae have to topple the pope from his exalted position and make him just another man on the street with just another opinion. There is no other way to resist Paul on this point.