Natural Family Planning and the Myth of Catholic Contraception

Is our culture close to turning a corner on Humanae Vitae, half a century after its promulgation and the widespread rejection of it that followed? There are reasons for cautious optimism. The historical context of the encyclical is important, given that it came just 38 years after Pope Pius XI’s Casti Connubii, which had already reaffirmed the longstanding Christian prohibition on contraception. What occasioned Humanae Vitae was really the emergence of the pill, which unlike barrier methods of contraception did its work inside the body, and so looked scarcely different from confining sexual intercourse to the woman’s infertile period.[1]

But while the pill is still the contraceptive of choice for many, there is now growing disquiet about its side effects. This is significant not just from the perspective of health but also a feminist one: We once thought the oral contraceptive liberating, but today the discourse is shifting towards recognizing that women are made to disproportionately bear the hormonal burden of birth control. Additionally, given our contemporary attraction to all things organic and natural, there is, rather unsurprisingly, an appetite for something of a “green” alternative to the pill.

It was in the midst of all this that the smartphone app “Natural Cycles” sprung onto the scene, and was greeted with something of a media fanfare last year. “Contraception? There’s an app for it,” read the headlines, when it became the first smartphone app to be certified as a “contraceptive” in the European Union. It is old-school fertility awareness combined with new technology and know-how: The app works by applying a complex algorithm to a woman’s temperature readings in order to predict her fertile and infertile days.[2] Marketed as “non-hormonal and non-intrusive,”[3] it seemed like the answer to those burgeoning concerns about the pill.

To the optimist, this might be read as the beginning of the end of the pill, and with it the contraceptive mentality of contemporary culture. But such optimism must be tempered with realism. So long as fertility awareness methods like “Natural Cycles” continue to be thought of as “natural contraception,” the teaching of Humanae Vitae will remain somewhat obscure.

This problem here is not one of semantics, but intelligibility. For every so often, one continues to hear that the of use fertility awareness to space pregnancies, endorsed by Humanae Vitae as licit,[4] is simply “Catholic contraception.” This invariably leads people to one of two conclusions: Either natural family planning (NFP) is not acceptable because it is contraception plain and simple, or, other forms of contraception should be similarly permitted. The question of the morality of NFP is therefore fundamentally a question of what precisely the Church is against when she says she is against contraception, and whether she is consistent in this belief.

My aim in this essay is, ultimately, this: I want to make the case that fertility awareness-based methods are simply not contraception, and that this is consistent with the teaching of Humanae Vitae. But to do so we would do well to place our discussion in the wider context of marriage and marital love, lest we become like strange botanists who fixate on the thorns and neglect the blooming of the rose.

The Eucharist and Marital Love

As a starting point, it is worth reflecting on how, as Christians, we are accustomed to calling the Eucharist “the marriage supper of the Lamb.” What significance does earthly marriage hold for understanding this, and vice versa?

On the evening of Maundy Thursday, 1960, a Spanish priest by the name of Josemaría Escrivá began his homily on the Eucharist by speaking precisely about human love. Those who love each other, he said, often seek to express that love in some kind of symbol—a gift, perhaps an image of oneself—especially when one cannot always remain physically with one’s beloved. “They can do no more, because a creature’s power is not so great as its desire.” But through the Eucharist, Christ is able to give us not a mere symbol but his very own self.[5]

In the Eucharist, then, one finds the perfection of the call to love that comes from deep within our being. Love for another impels us to give not just gifts but our very lives—our whole being—to the beloved. Yet, this is not the same as wanting to be a slave, which would not just be repugnant but antithetical to love. Love seeks mutual reciprocity. But what are the practical implications of this? Is it even possible to give one’s whole person to someone else, and yet truly remain one’s own person? In posing this question we are like the disciples who asked, “How can this be? How can this man give us his flesh to eat?”

For all our reliance on symbols to express the depths of our love for others, there is in fact one way in which we can give ourselves completely to another person, and not just figuratively speaking. And that is none other than marriage. We frequently receive all kinds of gifts at weddings, but the one gift that makes marriage what it is, is the mutual gift of self—pledged in the vows (ratum), actualized in marital intercourse (consummatum). The gift of one’s body in marriage, where two shall become one flesh, is an image of the Eucharist, and “this mystery has many implications.”

The consummation of marriage, as with all other complete sexual acts within marriage that follow, is not just one way among many of expressing marital love. Rather, marital intercourse is the way of expressing the covenantal love of marriage; it is constitutive of marriage. That is why we call it “the marital act.” It is where, as in worthy reception of the Eucharist, both give their whole persons to each other, without reserve, in order to be united physically and spiritually. This mutual self-giving ought also to animate all other acts of love within marriage, however dramatic or mundane. It is not, after all, a mere feeling experienced during sex, but a way of living two lives as one.

A Natural Law Account of Sexuality

Such a worldview, though distinctly Christian, is rooted in a natural law understanding of marriage that is in principle accessible to everyone. We can understand that fervent desire to give oneself to another without having any understanding of the Sacraments or indeed any divine revelation at all, although knowledge of the Eucharist surely reminds us that our nuptial vows, though beautiful in themselves, point to something still more profound and beautiful.

The hallmarks of marriage—unity, procreation, indissolubility—are rooted in our shared human nature. That is why St. Thomas Aquinas calls marriage an “office of nature,”[6] and this is the case for both Christians and non-Christians. When marriage occurs between the baptized, it is also a Sacrament; but, as St. Thomas says elsewhere, grace perfects nature but does not destroy it.[7]

On the level of nature, we can already understand why marriage is not, as it is often mistaken to be these days, simply a pledge of lifelong love and friendship. Rather, it is a distinctive kind of such a pledge. But what is the source of that distinctiveness?

The answer is a twofold one, and lies in the very nature of the sexual act. Firstly, it is evident that, so long as each individual instance of sexual intercourse lasts, sex has a strict biological exclusiveness built into the way it unites two people together. Furthermore, it has a procreative power that also requires just two—no more, no less—to actualize.

Our recognition of those powerful facts of our sexuality makes us seek some means of protecting the goods of conjugal fidelity and procreation, which seem to call out for more than just casual, temporary arrangements. Of course, as rational beings, we are uniquely capable of making promises of various kinds and with varying timespans. We can thus pose these two questions to ourselves: What sort of promise seems to best fulfil this natural call of our sexuality? What form of relationship fulfils that deep-seated desire in us to give of ourselves completely to another, and yet remain one’s own person?

The beauty of human love is that these two questions find their answer in the same place: The institution of marriage. It is a truth about our nature that we grasp, not perhaps by deductive reasoning, but through self-knowledge—through an inner perception[8] that our sexuality is made for, and is best served by, a kind of permanent friendship that we pledge for a lifetime with one other person. Our innermost being directs our understanding to the truth that sexual intercourse is not just a mere bodily exchange of biological material that also happens to be pleasurable, but is inherently made for love.

In this way, we can make sense of marriage as a permanent, exclusive union for unitive sexual love and childbearing. As an office of nature, it is more than just a legal arrangement; it is a mode of being, through which we find a new identity as a person, and build a new nexus of relations in which our children find their identities, and our children’s children, and so on. We recognize this from the way we perceive flesh and blood relations to not be brute biological facts, but to permanently ground identity and carry obligations which are independent of any legal framework,[9] and provide the basis for the rights of the family under the state.

The Contemporary Culture: Marriage as Mere Contract

On a natural law account, then, marriage can be seen as a particular kind of friendship that arises out of human sexual complementarity. Sex, with its biologically exclusive structure for unity and procreation, make sense as the consummation of the public vows of marriage, and not just as an incidental fact to the relationship. Our bodies can be said to have a natural nuptiality—a made-for-marriage-ness.

This means that sexual intercourse has a particular integrity that must be respected, since it is that by which marriage makes any sense at all. And it is at this point that our modern cultural understanding of sex, with its reliance on contraception, encounters a great practical difficulty. If marriage exists precisely because of our nature as sexed and sexual beings, then to alter or frustrate the nature of the sexual act is to strip it of its intelligibility vis-à-vis the marital relationship. The consequence is that marriage in turn becomes less intelligible to society—not that its fundamental nature can be changed, but in that the concept that people hold in their minds is subject to corruption.

The question of sex and contraception is therefore, at its core, a question of what form of friendship marriage really is. For any attempt to separate the unitive from the procreative dimensions in sex is inescapably confronted with the following dilemma: Were marriage just a promise between two people of lifelong friendship, it would be little different from other close relationships. Were it just about procreation, then, like other animals, there would be no intrinsic reason for exclusivity.

Of course, if marriage is not per se connected to sex, then it is more difficult to make sense of why the integrity of the complete sexual act must always be respected. Sex becomes just one of many ways in which a couple express their love, but there is no inherent reason to restrict it to marriage, or to not alter its character. Of course, there might still be pragmatic reasons to keep a sexual relationship exclusive, especially when procreation comes into the picture. Marriage would be a public way of proclaiming that exclusivity, but not the only means of doing so. All this is already being borne out by contemporary society.

Fundamentally, in this merely contractual view of things, marriage is nothing truly special compared with other relationships with lifelong friends. Its attendant legal rights and protections will still give it a particular attraction and utility, but if cultural memory is sufficiently eroded over time then society will come to ask why marriage is called “marriage” at all. Is it not just a “civil partnership”? Is it not simply a legal contract, like any other? Needless to say, indissolubility would no longer be an essential part of it. The word “marriage” and its mesmeric force[10] will become seen as a relic of a bygone era—ultimately dispensable when divorced from a nuptial account of sexuality.

Traditional Christian teaching on contraception cannot be understood without this sense of what is at stake. It stands at the dividing line between the two rival conceptions of marriage and sexuality I have outlined—a nuptial view, and a purely contractual view. No doubt, the rise of contraception is linked both to the abandonment of the former view as well as the emergence of the latter view in our time. As Pius XI astutely observed in Casti Connubi, the “basic principle” of contemporary attacks on the sanctity of marriage lies in this, “that matrimony is repeatedly declared to be not instituted by the Author of nature . . . but invented by man” (§49).[11]

Natural Family Planning and Contraception

With the two rival accounts of marriage in mind, it is easier to see what precisely the Christian tradition is against with regard to contraception. From the perspective of the nuptial view of sexuality, contraceptive sex is simply an unintelligible act.

But at this point a question may arise as to how infertility fits into the picture—whether those who are infertile are incapable of entering into marriage, if marriage is for procreation. If the answer is yes, then surely sexual intercourse between an infertile couple is no different from contraceptive sex? It is not difficult to see how the question concerning NFP follows from this. After all, even a woman in perfect health is only actually fertile some of the time—a normal menstrual cycle has in-built fertile and infertile days. It would seem that sex during the infertile days is “contraceptive.”

It is important to stress that in the nuptial view of sexuality, marriage arises out of our shared nature, not our individual capabilities. Nature in this sense is not mere empirical data about our biology, but the essence shared by members of our species which makes us human. We are by nature sexual beings who are sexually differentiated; the call to marriage is something built into that nature, not invented by our rationality as the contractualist view of marriage would have it. This means that even if a person is infertile for whatever reason, he or she is not thereby excluded from the institution of marriage—for such a person is still a bearer of sexuality, and that sexuality is still made for procreation.

What would make a difference is impotence—if a couple were unable to perform the sexual act—as the putative marriage cannot be consummated.[12] But in making this point I am not reducing sexuality to the sexual act itself. Rather, it is to stress that, after all, marriage still requires the marital act, which retains its unitive and procreative significance even without, for example, ovulation. One might note how even intercourse before ovulation has taken place can still lead to pregnancy; that biological fact suggests that the occurrence of ovulation itself should not be taken as a necessary condition of proper marital intercourse. Thus what is necessary for marriage is a sexual act that is the kind of act that is unitive and procreative. But it is not necessary that procreation is intended in each instance of marital intercourse.

All this should give perspective to why NFP is not a form of contraception. Perhaps, there is often too much focus on the fact of sexual intercourse during infertile days. But we forget that NFP—when used to avoid rather than achieve pregnancy—works by not having intercourse during fertile days. Surely, there should be no problem with abstinence for the adherent of traditional Christian teaching.

We might begin here by repeating the observation that there is nothing intrinsically wrong with sex during a woman’s infertile period, as it is still a procreative-type act. Secondly, we can safely assume that there is no obligation to have sex just because one knows one is fertile (Indeed, one will search in vain to find in Casti Connubi or Humanae Vitae an obligation to chart one’s fertility). Yet there is still a certain amount of unease among some people about the intention of deliberately having sex only when it will not lead to conception. No doubt, it does look like it is contra conception.

This is where the notion of intention has often led to misunderstandings about the difference between contraception and NFP. Of course, as Elizabeth Anscombe pointed out in her classic essay “Contraception and Chastity,” it is true that the oral contraceptive pill is different from the body’s infertile period because of the “contraceptive intention” accompanying its use, and this helps us to understand it as contraception since it does not seem to alter the sexual act in the way that barrier methods of contraception do.[13] Humanae Vitae thus made it abundantly clear that “excluded is 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” (§14).[14]

However, what this statement from Humanae Vitae does not say is that the intention to avoid pregnancy for a time is intrinsically contraceptive, or even morally wrong. In fact, where there are good, serious reasons to space pregnancies, then this intention can be pursued by married couples with tranquillity of conscience, provided the right means are employed.

What, then, is a “contraceptive intention” if not an intention to avoid pregnancy? Note that what Paul VI says is that morally excluded is “every action which . . . proposes . . . to render procreation impossible,” not the mere intention. An explicit connection is made here with the conjugal act. It is thus evident that contraceptive intentions can only be sensibly understood in conjunction with an action that intentionally frustrates the procreative potential of a sexual act (or acts), whether before, at the moment of, or after it. It is this kind of contraceptive “intentionalness” in an action, as Anscombe calls it, that is prohibited.[15]

But an action that is not connected to the sexual act in this way, and which is pursued by a couple to help them abstain and so prevent procreation, does not have this intentionalness. Otherwise, the couple who decide to play tennis to avoid sex on a fertile day would be guilty of a “contraceptive intention”—such a conclusion can only be reached by twisting Paul VI’s words beyond their natural meaning.

This account helps make sense of the following distinction: Whereas barrier methods of contraception always carry the intentionality of disrupting a sexual act’s procreative function because of the physical structure of the act,[16] the pill does not necessarily do so on account of the different structure of its workings. Because the occurrence of ovulation is not essential for a sexual act to be marital, the pill can be licitly prescribed when there are proportionately grave medical reasons, where the intention behind its use has nothing to do with avoiding conception. Marital intercourse need not be excluded during this period.

The problem is where the stopping of ovulation is deliberately intended. Though the pill is taken some time before intercourse, it is properly contraceptive in intention because the very action is done to make future sexual acts infertile. By contrast, sexual intercourse deliberately chosen when a woman is infertile (whether periodically or permanently) is not an action that has the intentionality of preventing procreation. Here, one has simply chosen an action that is incapable of leading to procreation, not acted deliberately to frustrate the procreative potential of a sexual act.

Thus, there is a categorical difference between contraception proper and the use of fertility awareness to decide when to have intercourse. Whether it is through the Billings Method or the “Natural Cycles” app, even when one confines intercourse to the infertile period, one is still performing a reproductive-type act that one is not simultaneously, or at some other time, acting against. Hence, NFP is simply not contraceptive, and does not offend the nuptiality written into our sexual nature. In fact, it is meant to be at the service of marriage and the family, to promote the common good of the shared life of parents and their children.

Final Reflections: On the “Contraceptive Mentality”

It is possible, then, that with NFP one is still able to exercise “responsible parenthood, lived in respect for the full truth of the conjugal act”—to borrow Pope John Paul II’s words in Evangelium Vitae (§13). Notably, however, in the same paragraph of that encyclical this ideal is contrasted with what John Paul II terms the “contraceptive mentality,” whose values set the heart so strongly against procreation that when one is faced with an unplanned pregnancy the temptation to “remedy” the situation with abortion is thereby increased.[17]

It is thus apt for us to turn to one last question: Can NFP be used with a “contraceptive mentality”?

Often when this question is asked one cannot help but feel that NFP is being unfairly singled out, due to misconceptions about intention that have hopefully been clarified by now. If what is meant by that question is, “Can NFP become contraceptive because of a fault of the mind?” then the answer is that it is simply impossible that any state of mind alone can somehow turn a true act of marital intercourse into a contraceptual act. The mind can turn it into a selfish, or unloving, act, but making it contraceptive just by a mental act is beyond its powers.[18]

But if by “contraceptive mentality” we mean a rejection of the nuptial view of sexuality—a rejection of the intrinsic link between sex and procreation, or worse, a rejection of the view that sexuality exists for marriage and marital love—then of course the use of NFP can be distorted by a contraceptive mentality. But this is not just a problem for NFP users; even casual sex without contraception can be engaged in with a contraceptive mentality. The fault of the contraceptive mentality, though it colors one’s sexual actions, is at its root one of false understanding.

That is why, in the final analysis, NFP calls for deeper reflection on the meaning of our sexuality vis-à-vis marriage. Certainly, it is not the particular method of fertility awareness chosen, however scientifically advanced and accurate, that can be relied on as an absolute safeguard against the contraceptive mentality of our time. Nonetheless, because it is not intrinsically anti-nuptial, NFP still presents to couples a conducive space for appreciating more fully the truth of the conjugal act, in a way that contraception does not.

Ultimately, what is needed for any family planning is a genuinely nuptial spirit: A necessary part of this is the sacrifice of abstinence, which though painful is undergone as a sign and a means of preserving the unity and exclusivity of the sexual relationship—much like how the thorns of a rose help guard against unwelcome visitors. Combined with an awareness that even in infertile marital intercourse one is still acting in a procreative manner, the sexual encounter of husband and wife can continue to flower in self-giving love and openness to life.

[1] Elizabeth Anscombe, Contraception and Chastity (London: Catholic Truth Society, 2003), 28–29. Pope Paul VI does not refer explicitly to the oral contraceptive pill in Humanae Vitae (1968). Nonetheless he makes reference to “man’s stupendous progress in the domination and rational organization of the forces of nature to the point that he is endeavoring to extend this control over every aspect of his own life . . . even over the laws that regulate the transmission of life” (§2). Accessed 28 February 2018.

[2] Maddy Savage, “The Swedish physicist revolutionising birth control,” BBC News, Aug. 7, 2017. Accessed 28 February 2018.

[3] According to the Natural Cycles website, “Natural Cycles is a natural contraceptive method that is non-hormonal and non-intrusive.” Accessed 28 February 2018.

[4] Paul VI writes thus in Humanae Vitae, §16: “If therefore there are well-grounded reasons for spacing births, arising from the physical or psychological condition of husband or wife, or from external circumstances, the Church teaches that married people may then take advantage of the natural cycles immanent in the reproductive system and engage in marital intercourse only during those times that are infertile, thus controlling birth in a way which does not in the least offend the moral principles which We have just explained.”

[5] Josemaría Escrivá, “The Eucharist, Mystery of Faith and Love” in Christ is Passing By (Manila: Sinag-Tala, 1974), 121–122.

[6] Thomas Aquinas, The “Summa Theologica” of St Thomas Aquinas, trans. Fathers of the English Dominican Province (London: Burns, Oates and Washbourne, 1920), Suppl., Q. 49, Art. 2, co. Also available online:

[7] Ibid., I, Q. 1, Art. 8, ad. 2. Also available online:

[8] By “inner perception” I have in mind the concept of connatural knowledge in natural law, which Jacques Maritain helpfully describes as “a kind of knowledge which is produced in the intellect but not by virtue of conceptual connections and by way of demonstration,” but rather “through inclination, by looking at and consulting what we are and the inner bents or propensities of our own being . . . the intellect is at play not alone, but together with affective inclinations and the dispositions of the will, and is guided and directed by them.” See: Jacques Maritain, “On Knowledge through Connaturality” in Natural Law: Reflections on Theory and Practice, ed. William Sweet (South Bend, IN: St. Augustine’s Press, 2001), 13–24. While it is possible to come to a conception of marriage as exclusive and procreative via deductive reasoning about sexuality, such a thought process can take on an uncomfortably utilitarian character; it seems to me that our grasp of marriage as a natural institution, and of sexuality as made for marriage, is fundamentally connatural. However, that is not to say that learning about marriage as fulfilling our desires for sexual love and childbearing through social experience (of other married couples, for instance) has no role in refining this connatural grasp, for it is often through relationships with others that we learn more about ourselves and our shared human nature.

[9] I have previously made this point about genetic ties in an article on donor conception and “three-parent” IVF. See: Michael Wee, “Genetics, identity and three-parent babies,” The Straits Times, July 7, 2017, A24. Also available online:

[10] I have borrowed the phrase “mesmeric force” from Anscombe’s celebrated paper, “Modern Moral Philosophy,” Philosophy 33:124 (1958), 8. In the paper, Anscombe famously contends that the word “ought” has, in modern moral philosophy, retained a peculiar “mesmeric force” even though the Judeo-Christian worldview that gave substance to such a force in earlier conceptions of ethics has been abandoned by philosophers. There is something of an analogy with the word “marriage” in contemporary culture, which is still, on the face of it, treated as something of great significance and therefore celebrated in great style, even though the institution of marriage is understood very differently by different groups of people today.

[11] Pope Pius XI, Casti Connubi (1930). Accessed 28 February 2018.

[12] For a more detailed discussion of impotence and infertility in relation to the marital act, see: Luke Gormally, “Marriage and the Prophylactic use of Condoms,” Faith Magazine, Mar. 1, 2006. Accessed 1 March 2018.

[13] Anscombe, Contraception and Chastity, op. cit., 29.

[14] In this instance, I have quoted from the NC News Service English translation which was published as Pope Paul VI, Of Human Life: Humanae Vitae (Boston, MA: Pauline Books & Media, 1968). Its rendering of this sentence in Humanae Vitae, §14 is much closer to the official Latin text than the English translation on the Holy See’s website. The Latin reads, “Item quivis respuendus est actus, qui, cum coniugale commercium vel praevidetur vel efficitur vel ad suos naturales exitus ducit, id tamquam finem obtinendum aut viam adhibendam intendat, ut procreatio impediatur.” Accessed 1 March 2018.

[15] Anscombe, Contraception and Chastity, op. cit., 30.

[16] This is important for understanding why the use of condoms with the intention of preventing the transmission of AIDS cannot be admitted into Catholic moral life under the principle of double effect. As Nicanor Pier Giorgio Austriaco, O.P. points out in Biomedicine and Beatitude: An Introduction to Catholic Bioethics (Washington, D.C.: The Catholic University of America Press, 2011), 92, “the physical structure of a human act limits the moral objects that can be legitimately chosen to specify it from the perspective of the acting person in the same way that matter limits form . . . Using a condom necessarily impedes the procreative nature of the conjugal act . . . Thus, despite their further intention to prevent the transmission of the AIDS virus, a couple using a condom for prophylactic purposes cannot claim that they are not engaged in a contraceptive act.”

[17] Pope John Paul II, Evangelium Vitae (1995), §13. Accessed 1 March 2018.

[18] On this point I am indebted to Simcha Fisher, who has also discussed the question of NFP and the “contraceptive mentality,” and writes with much-needed clarity and common sense that “[i]t is possible to use NFP selfishly. But that’s the sin of selfishness, not the sin of contraception.” See: Simcha Fisher, The Sinner’s Guide to Natural Family Planning (Huntington, IN: Our Sunday Visitor, 2014), Kindle Edition, 22.

Featured Image: Model of a contraceptive pill, Europe, c. 1970, by Wellcome Images; Source: Wikimedia Commons, CC BY 4.0.


Michael Wee

Michael Wee is the Education Officer of the Anscombe Bioethics Centre, a Catholic academic institute based in Oxford. He co-teaches bioethics at St Mary's College, Oscott, which is the seminary of the Archdiocese of Birmingham, and has written on contemporary ethical issues in the Catholic Herald and Public Discourse.

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