No, Natural Family Planning Is Not Contraception

The Church's Clear Distinction Makes All the Difference

Deep Dive Podcast
Audio segment produced with AI narration summarizing Patrick Madrid’s written content.

ANOTHER TOPIC that resurfaces from time to time on my radio show concerns Natural Family Planning, commonly referred to as NFP. For reasons that remain puzzling, a small, misguided, and vocal segment of the “traditionalist Catholic” world insists that it is immoral for married Catholic couples to make use of Natural Family Planning for the purpose of avoiding conception, typically for serious reasons such as health concerns, financial hardship, or other legitimate circumstances.

Calls come in occasionally from Catholics who flatly assert that NFP is contrary to the moral law and who equate it with contraception. Some go further and claim that couples who practice NFP are committing grave sin.

These objections overlook key historical approvals, and remain directly contradicted by Sacred Scripture, the constant teaching of the Church, the Popes, the Fathers, and the mainstream tradition of Catholic moral theology.

Periodic continence within marriage is nothing new. What is new is the scientific sophistication with which a woman’s cycle can now be observed and charted. The moral principle involved, however, remains exactly the same as it has always been.

Scripture and Periodic Abstinence

The Bible is clear that married couples may abstain from marital relations for a time, by mutual consent, for a legitimate reason.

The husband should give to his wife her conjugal rights, and likewise the wife to her husband. For the wife does not rule over her own body, but the husband does; likewise the husband does not rule over his own body, but the wife does. Do not refuse one another except perhaps by agreement for a season, that you may devote yourselves to prayer; but then come together again, lest Satan tempt you through lack of self-control.
(1 Corinthians 7:3–5)

This passage is key. Temporary abstinence within marriage, undertaken by mutual consent of the spouses and for a good purpose (e.g., prayer), is not sinful.

The Church’s Official Teaching in the Catechism

“A particular aspect of this responsibility concerns the regulation of procreation. For just reasons, spouses may wish to space the births of their children. It is their duty to make certain that their desire is not motivated by selfishness but is in conformity with the generosity appropriate to responsible parenthood.

“Moreover, they should conform their behavior to the objective criteria of morality: When it is a question of harmonizing married love with the responsible transmission of life, the morality of the behavior does not depend on sincere intention and evaluation of motives alone; but it must be determined by objective criteria, criteria drawn from the nature of the person and his acts criteria that respect the total meaning of mutual self-giving and human procreation in the context of true love; this is possible only if the virtue of married chastity is practiced with sincerity of heart” (CCC 2368; see Gaudium et Spes 51:3).

Before considering the specifics of the Church’s teaching, it is worth briefly summarizing the kinds of objections I’ve frequently encountered on from callers and that I have seen online.

Some argue that NFP is merely contraception “by timing.” They claim that any deliberate effort to avoid conception violates openness to life, regardless of the means employed.

Others claim that spouses who practice NFP are exploiting a moral loophole, allegedly manipulating nature in order to enjoy marriage while avoiding children, and that this mindset is no different in principle from artificial birth control.

A related argument holds that recourse to infertile periods reflects a “lack of trust” in Divine Providence, and that couples who seek to avoid pregnancy, even temporarily, are resisting God’s will.

Still others insist that while abstinence may be lawful for prayer (per Saint Paul), abstinence chosen specifically to avoid conception is a corruption of the marital vocation, ordered toward procreation, and thus transforms NFP into a de facto contraceptive practice.

These claims may sound traditional, but they collapse under scrutiny.

Answering Arguments Equating NFP with Contraception

Some critics insist that Natural Family Planning requires grave reasons, not merely serious or just ones, often citing selective translations of Pius XII or early drafts of Humanae Vitae. Yet the official text of Humanae Vitae no. 16 refers to just reasons, a formulation found in the Catechism of the Catholic Church (2368).

Pope Pius XII’s reference to “grave reasons” (a term he uses once) and “serious motives” (three times) in his 1951 “Address to Midwives” (Vegliare con Sollecitudine: To watch over with solicitude) applies specifically to long-term or permanent avoidance of pregnancy.

The Church’s explicit endorsement of periodic continence predates Vatican II by decades. Pope Pius XI, in his 1930 encyclical Casti Connubii, affirmed the lawfulness of marital relations during naturally infertile periods, provided no artificial means are used to frustrate procreation (i.e. contraception).

Pope Pius XII’s “Address to Midwives” also declared that married couples may abstain from marital intimacy during the wife’s infertile periods for serious reasons without sin.

“Serious motives, such as those which not rarely arise from medical, eugenic, economic and social so-called ‘indications,’ may exempt husband and wife from the obligatory, positive debt for a long period or even for the entire period of matrimonial life. From this it follows that the observance of the natural sterile periods may be lawful, from the moral viewpoint: and it is lawful in the conditions mentioned.” (ibid.).

“If, however, according to a reasonable and equitable judgment, there are no such grave reasons either personal or deriving from exterior circumstances, the will to avoid the fecundity of their union, while continuing to satisfy to the full their sensuality, can only be the result of a false appreciation of life and of motives foreign to sound ethical principles.”

These pre-conciliar popes, expounding the Church’s unchanged magisterial tradition, demonstrate that NFP’s moral foundation is rooted in Church doctrine and is not a post-Vatican II novelty.

The argument that only “grave” or “very grave” reasons justify the use of NFP is a complete misrepresentation of the Church’s teaching on this issue. That language appeared only in early drafts of Humanae Vitae and was deliberately omitted in the final, authoritative text which speaks of “well-grounded reasons” and “just reasons” (see 10, 16), in keeping with Pope Pius XII’s reference to “serious motives” and the Catechism’s consistent use of the phrase “just reasons” (CCC 2368). By appealing to early drafts instead of the final official version which reflects the Church’s actual teaching, critics of NFP attempt to impose a stricter standard than the Church Herself requires of married couples.

Angela D. Bonilla’s article, “Humanae Vitae: Grave Motives to Use a Good Translation” (Homiletic & Pastoral Review, May 2007; posted online at Catholic Culture), shows how gravi motivi (“grave motives”) in the Italian draft led to a more rigorist interpretation. She shows that the final, official Latin version instead uses seriis causis (serious reasons) and iustae causae (just causes), which the official English translation renders as “well-grounded reasons,” thus avoiding a rigorist slant.

Thomas Storck makes the same point in his 2013 article, “The Curious Controversy Over Natural Family Planning” (Crisis Magazine), noting that claims about Humanae Vitae requiring “grave” reasons are based on an early Italian draft, not the authoritative final Latin text. He points out that “serious reasons” and “just reasons” were the correct formulation reflected in Humanae Vitae 16 and the Catechism of the Catholic Church 2368.

Although some English versions of Humanae Vitae used the phrase “grave reasons,” the authoritative Latin edition refers to iustae causae (“just causes”), as Bonilla and Storck show. This language conforms to Pius XII’s use of “serious motives” in his “Address to Midwives,” which gives examples such as medical, financial, and social circumstances.

In Familiaris Consortio (32), Pope John Paul II warned against a “contraceptive mentality” that selfishly rejects generosity toward life, a mindset that can distort any method, including NFP if misused. However, when a couple practices NFP virtuously, as Pius XII affirmed, their periodic continence arises from serious, objective reasons that are typically medical, economic, or social.

Properly intended, a couple’s use of NFP fosters trust in Divine Providence and guards against the very “contraceptive mentality” NFP critics fear.

Others misread Casti Connubii (1930) as condemning all intentional avoidance of conception. In reality, Pope Pius XI condemns acts that deliberately frustrate the marital act by depriving it of its procreative power. He does not mention periodic continence at all. That silence is significant, especially given the historical context. The encyclical was written in response to the Anglican Communion’s fateful approval of artificial contraception earlier that same year.

Long before Vatican II, the Holy Office (later the Congregation for the Doctrine of the Faith) under Pope Pius IX (1853), Pope Leo XIII (1880), and later popes explicitly approved advising couples to practice periodic continence when struggling with temptations to contraception, provided nothing interfered with the marital act itself.

A June 16, 1880 response from the Sacred Penitentiary (now known as the Apostolic Penitentiary) states that married couples using marriage only on days when conception is more difficult “are not to be disturbed,” and confessors may cautiously suggest this to deter the “detestable crime of onanism,” a reference to Onan’s contraceptive sin of withdrawal, condemned by God and punished severely in Genesis 38:8–10. (See Fr. Brian W. Harrison, O.S., “Is Natural Family Planning a ‘Heresy’?”, originally published in Living Tradition (Roman Theological Forum).

That alone disproves the claim that NFP’s recourse to infertile periods by abstaining from the marital act represents a modern innovation.

Examples of Just Reasons to Use NFP

The Catholic Church teaches that spouses may, for just and serious reasons, postpone pregnancy by practicing periodic abstinence through Natural Family Planning. These reasons must be based on legitimately serious circumstances (e.g., physical, psychological, economic, etc.), not merely preference, convenience, or a desire for hedonism.

Here are a few concrete, real-world examples:

• A woman undergoing cancer treatments such as chemotherapy or radiation, where pregnancy could seriously endanger her life or health.

• A mother or father suffering from mental illness, such as bipolar disorder or debilitating postpartum depression, that makes it temporarily unsafe or unjust to bring another child into the situation.

• A family suddenly facing financial hardship, for example, the husband has lost his job, and the household has no income or savings to fall back on.

• A couple living in a war zone or refugee camp where basic needs like food, shelter, and security are uncertain or unavailable.

• A couple with a small home who have welcomed long-term guests, such as extended family or refugees, and who now lack the privacy, space, and stability needed for healthy marital and family life.

• A couple already caring full-time for a child with profound disabilities or serious medical needs.

• A couple caring for elderly, ailing parents and cannot presently extend themselves further without neglecting serious responsibilities, etc.

• A mother caring for a premature infant or a newborn with serious medical problems and who requires constant attention, medical monitoring, or frequent hospital visits.

• A couple already caring for several very young children at once, especially when births have occurred in rapid succession and the mother’s health, recovery, or ability to care adequately for the children she already has would be seriously strained by another immediate pregnancy.

• A mother recovering from severe postpartum depression, where another pregnancy could pose serious risks to her mental and physical health and to the stability and well-being of the family.

In such cases, avoiding pregnancy through NFP and abstaining from marital intimacy is not a rejection of life but is a responsible, charitable, and morally upright and prudent response to difficult realities the couple faces.

Examples of Insufficient (Unacceptable) Reasons to Use NFP

The following examples are illustrative, not exhaustive. They assume that there are no significant medical, psychological, economic, or social circumstances that would justify postponing pregnancy for a time (see above).

A married couple wrongly uses NFP to avoid pregnancy because:

• They simply do not want children.

• They want to enjoy a carefree, child-free lifestyle.

• They want to travel without the responsibilities and complications of raising children.

• They are saving for luxuries or a higher standard of living rather than meeting their genuine needs.

• They want to accumulate a certain level of wealth before considering children, even though they are financially capable of supporting a family.

• She wants to preserve her figure or avoid the physical effects of pregnancy (e.g., stretch marks).

• He wants her to preserve her figure or avoid the physical effects of pregnancy.

• They view children primarily as an inconvenience or a burden rather than a gift from God.

• They prefer the comfort and freedom of life as a couple and do not want children to disrupt that lifestyle.

• They fear that children will interfere with their hobbies, entertainment, or recreational activities.

• They are postponing pregnancy merely because parenthood requires sacrifice.

• They are conforming to cultural attitudes and pressures that regard children as undesirable or burdensome.

• They reject the idea of trusting God’s providence while having no objectively serious reason to postpone pregnancy.

• They intend to avoid having children indefinitely despite having no proportionately serious reason for doing so.

As explained above, the Church recognizes that some couples may indeed be dealing with serious medical, psychological, economic, and social circumstances could morally justify postponing pregnancy for a time. There is a clear distinction between responsible parenthood, which calls for prudence as well generosity, sacrifice, and self-giving, versus a contraceptive mentality characterized by an unwillingness to embrace the sacrifices inherent in being open to life and welcoming children.

Does NFP = “A contraceptive Mentality”?

No. The Church has consistently taught that Natural Family Planning is not the same as contraception. Still, some accuse those using NFP of nonetheless being guilty of having a “contraceptive mentality” even though they aren’t technically using contraception.

While selfish motives can certainly exist, the accusation here is mistaken because it wrongly absolutizes this concern, treating all use of NFP as morally compromised. Pope John Paul II acknowledged that NFP can be misused with a selfish spirit, but selfishness is a flaw in intention, not in the act itself.¹ The moral object of NFP remains distinct from contraception.

NFP does not suppress or sterilize the conjugal act; it simply refrains from it during fertile times. Abuse of a good does not nullify its legitimate use, and the mere possibility of misusing NFP does not redefine the nature of NFP as a morally legitimate practice.

Another version of this rigorist objection to Catholic teaching on NFP holds that it fosters a “contraceptive mentality,” effectively functioning as a “natural” form of contraception through the systematic use of abstinence during the fertile period.

Critics argue that when couples engage in marital intimacy during infertile times, even though the act itself remains fully open to life and does nothing to preclude the possibility of conception, they do so with the expectation that conception will not occur and thus seek the pleasure of the act while deliberately excluding, as evidenced by their abstinence during fertile periods, the procreative responsibility inherent in it.

On this view, no circumstance can justify abstaining to avoid conception, despite the Church’s teaching to the contrary. NFP is therefore judged to be fundamentally disordered and contrary to the meaning and purpose of marriage, even when practiced for a just reason and for a limited time. Such a position treats the couple’s intention as morally disordered in itself.

But the Church clearly rejects this rigorist approach. Both the Church and the rigorist critic agree that a couple who habitually uses NFP to avoid conception for the entirety of their marriage is acting sinfully and in a disordered manner, since such a permanent intention to exclude children denies the very meaning and primary end of marriage. On that point, there is no dispute.

The real dispute, though, is considerably narrower than the rigorist argument suggests. The question is not whether the permanent and systematic exclusion of children is sinful. It clearly is. The question is whether the temporary, occasional, seriously motivated spacing of children is similarly immoral. The Church clearly and decisively teaches that it is not.

The rigorist position, by contrast, goes far beyond what the Church herself requires by imposing a subjective moral standard, namely, that no sexual intimacy is ever licit unless procreation is specifically intended in each and every act. This is a standard the Church’s Magisterium has never taught and, in fact, explicitly contradicts.

This is an all-important distinction because, in the case of couples who eschew contraception in any form, their marital intimacy always remains naturally ordered toward the possibility of conception. Their intention is to space children for serious reasons, yet their openness to life remains intact should God will to bless them with children. Even while they judge it prudent to defer conception for a time, they do not exclude it but remain open to it.

The distinction between deferral (NFP) and permanent exclusion (contraception) is real and not a loophole. The Catholic Church’s teaching on marriage and procreation takes into account not only the marital act itself but also the real, concrete circumstances of married life as it unfolds, including the demands of health, finances, natural disasters, war, and similar serious circumstances.

As for real-world instances of couples using NFP exclusively and permanently to avoid children altogether, such cases would seem to be exceedingly rare. Moreover, the likelihood that a couple who actually has a contraceptive mentality choosing the discipline and self-denial entailed by NFP, rather than resort to contraception, including onanism, seems vanishingly low.

Another objection to NFP as a subtle attempt to equate it with contraception recently appeared in the comments section for this article. I add it here for additional clarity: Aren't NFP and contraception just "different means to the same purpose?"

My response: That's like saying that dieting (NFP) and bulimia (contraception) are just different means to the same end. Dieting is healthy and normal because it works with the body; bulimia is disordered and unhealthy because it directly frustrates a natural process.

Bulimia (contraception) enables the pleasure of eating the food but avoids the caloric responsibility because it is vomited back up before it can be digested. Dieting (NFP) is simply refraining from eating the food.

Regardless of the end, NFP and contraception are completely different. The “purpose” doesn't make the two things the same. Contraception is an immoral action; NFP is a non-action, that is, refraining from an act.

This same analogy also answers the concern that NFP could be misused as a permanent strategy to avoid conception altogether. Any attempt to fast permanently would be disordered, injurious, and eventually lethal, and even Christ Himself ate food after His own extended forty-day fast before commencing His public ministry. Just as the Church condemns as immoral the act of starving oneself to death by permanently abstaining from food, it equally condemns the choice of a married couple to use NFP continuously and permanently for the sole purpose of perpetually excluding any possibility of conception.

The Church has always consistently condemned contraceptive acts that deliberately frustrate procreation, such as Onanism (see Genesis 38:8–10), but permits marital relations during natural infertility.

St. Augustine, in On the Good of Marriage, affirms this, as does St. Thomas Aquinas (Summa Theologiae, Suppl. q. 49), stating that intercourse during known infertility, including old age and barrenness, is not sinful so long as the infertility is not artificially induced and the possibility of procreation is not impeded.

This principle is echoed in Pope Pius XI’s Casti Connubii, which affirms that timing alone does not render an act immoral. What matters is not only the intention and circumstances, but also the moral object of the act itself. When the act is not contraceptive in itself, and refraining from marital intimacy is not, it still must not be rooted in selfishness or vice and must be rightly ordered to the possibility of conception.

He explicitly condemns as immoral any act that would frustrate the procreative nature of the marital act, but he also teaches that husband and wife do not commit sin or act against nature by engaging in marital relations even during times when infertility is naturally present (e.g., old age, pregnancy).

This same and vitally important distinction between refraining from intercourse (as in Natural Family Planning) and corrupting intercourse by impeding its procreative nature (as in contraception) is crucial. The Church has explicitly taught that the former is morally permissible, while the latter is intrinsically and gravely sinful.

When evaluating the morality or immorality of an act, three things must be considered: (1) the act itself, also known as the object of the act, (2) the intention, and (3) the circumstances. These three are intrinsically related but distinct, which means that the act itself is not the same thing as the motive or intention behind the act.

As the Catechism explains:

“It is therefore an error to judge the morality of human acts by considering only the intention that inspires them . . .” (CCC 1756).

“Circumstances or intentions can never transform an act intrinsically evil . . . into an act ‘good’ or ‘defensible as a choice’” (CCC 1753).

The inverse of this principle is equally true: The intention to avoid conception for a serious reason cannot render the morally neutral or morally good choice of abstinence (that is, refraining from intercourse during the fertile period) intrinsically evil. Contraception, however, deliberately corrupts the marital act itself; therefore, no intention, no matter how serious, can render it morally good.

One’s intention can be immoral (that is, a “contraceptive mentality”),² but that does not and cannot render refraining from the act (that is, abstinence) immoral or sinful.

This is why, in the case of a couple using NFP, there actually is no morally relevant act directed against procreation, because they refrain from marital intimacy during the fertile time. Their choice concerns whether to engage in the marital act at all, not how to perform or alter the act itself.

By contrast, in the case of a couple using Onanism or some artificial form of contraception, they do engage in the act of marital intercourse, but in a corrupted way, because they have foreclosed the possibility of procreation while hedonistically enjoying the pleasure of the act divorced from the responsibility that goes with it.

Strictly speaking, abstinence involves a voluntary choice, but it is not a moral act against the nature of intercourse, since no act of intercourse takes place. Contraception, on the other hand, is a positive act that directly frustrates the procreative nature of the marital act itself.

The former is a non-act with respect to intercourse. The latter is an act.

An Appeal to “Providence”

Another objection raised against NFP appeals to Divine Providence. It argues that if God doesn’t “make mistakes” (He doesn’t), married couples should simply allow Him alone to determine when conception occurs, without recourse to discernment or planning as with NFP. There’s nothing whatsoever wrong with a couple living out their marriage exactly that way (Nancy and I did, and God blessed us with 11 children). But the problem with insisting on that approach is that it would entail that any attempt to space births for a just reason would mean the couple thinks they “know better than God.” But that is not so.

This objection misunderstands how Divine Providence and human responsibility interact. Catholic teaching affirms God’s sovereignty while also calling couples to responsible parenthood, which involves prudential judgment, not a Que Será, Será fatalism. Spouses have a legitimate right to consider health, financial, psychological, and other circumstances and allowing for that through NFP lets them cooperate with God’s design rather than resist and override it (as always happens with contraception). NFP offers a concrete way for married couples to live out the four cardinal virtues:

Prudence, which is the habit of right reason applied to action, discerning what ought to be done here and now.

Fortitude, which enables spouses to carry out that judgment with perseverance, especially when self-denial is required.

Justice, which orders their choices according to God’s law and the objective goods of marriage. And

Temperance, which moderates their natural desire for bodily pleasure, allowing spouses to refrain from enjoying marital intimacy for the sake of a higher good. Far from opposing providence, such discernment in NFP reflects fidelity to God’s will and the couple’s proper role in prudently discerning and cooperating with it.

Why Some NFP Critics Are So Sure—and So Wrong

Over the past 40 years, I’ve encountered countless Catholics who insist that NFP is contraception and thus immoral: in-person discussions, during Q&A sessions at my public lectures, via email, and frequently from callers on my daily radio show. I don’t dismiss their concerns as unworthy of consideration, nor do I question their sincerity and desire to know and live the truth.

Even so, I’ve long observed a consistent pattern. The overwhelming majority of those who hold that NFP is immoral have not actually read the authoritative Catholic sources I quote throughout this article. They’ve noticed similarities between NFP and contraception (similarities that are real but ultimately superficial), or they’ve heard from persuasive voices who reject NFP, but they aren’t familiar with what the Church’s Magisterium has explicitly and consistently taught on this question.

This creates a challenging dynamic. Their sincere, strongly held objections rest on incomplete information about what the Church actually teaches on NFP and why. Among some critics, limited exposure to the primary sources produces maximum confidence in their conclusions, while deeper study consistently reveals complexity and nuance their initial position did not account for. Confidence and correctness are not the same thing, and on this question, the gap between them is wide.

I say this from first-hand knowledge, because I’ve experienced it myself. Most likely, you have too. There have been multiple occasions when I held strong opinions on topics related to economics, politics, history, or other fields, only to discover after reading more deeply that my confident initial position was simply wrong. It happens to everyone. There’s no shame in revising or even abandoning mistaken opinions when confronted with better, more comprehensive evidence.

The challenge with NFP discussions is that many critics confidently assert positions about what “the Church teaches” without having examined what the Church has actually taught on this issue.

When I’ve asked, “Have you read the full text of Pius XII’s Address to Midwives?” or “Can you show me where in Casti Connubii this is condemned?” or “Are you familiar with the distinction between the object of an act, the intention, and the circumstances?” the answer is usually no. These things are vital to properly understanding the Church’s teaching on why contraception is morally wrong and NFP isn’t.

Other Common Objections

To the claim that NFP violates natural law universally and intrinsically

The natural law does not forbid spouses from making legitimate use of the natural cycle of the wife’s fertility when deciding whether or not to engage in the marital act. From the beginning, the Church has carefully distinguished between deliberately frustrating a fertile marital act (contraception) and choosing to refrain from sexual intercourse during the fertile period (see Humanae Vitae no. 16; Pius XII, Address to Midwives, 1951).

Contraception is intrinsically evil, but NFP is a periodic continence, analogous to fasting from food, and can be morally licit for just reasons. Abstinence from the marriage act does not violate the nature of the act, which contraception always does.

To the claim that Casti Connubii teaches there are no exceptions whatsoever to avoiding conception

Casti Connubii (1930) condemns “acts” that deliberately frustrate the procreative power of the marital act itself. It does not address periodic continence at all. The encyclical was written in direct response to the Anglican Communion’s decision that same year to permit artificial contraception.

The clearest evidence that Casti Connubii does not prohibit NFP is that Pope Pius XI himself did not interpret it that way. Both before and after 1930, Vatican responses on the topic continued to affirm the legitimacy of periodic continence as a remedy against contraception and as morally licit for serious reasons.

To the claim that the sinfulness of contraception is the intent to have relations while deliberately planning to avoid conception

Intent alone does not define the moral object of an act. Contraception is evil because it deliberately renders the marital act sterile. NFP involves no such attempt. When the marital act occurs, it remains fully ordered to procreation.

To the claim that all use of NFP constitutes mortal sin, regardless of reasons or circumstances

The Church has consistently rejected this claim. From the teachings of Popes Pius XII, Paul VI, and John Paul II, the Church has consistently affirmed that periodic continence for serious or just reasons is not sinful. Simply put, the notion that all use of NFP is a mortal sin contradicts Church teaching.

The Church’s Magisterium on NFP

Pope Paul VI, Humanae Vitae, no. 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.

Paul VI says that recourse to infertile periods is not contraception and is not immoral.

Pope Pius XII, Address to Midwives (1951)

Serious motives, such as those which not rarely arise from medical, eugenic, economic and social so-called “indications,” may exempt husband and wife from the obligatory, positive debt for a long period or even for the entire period of matrimonial life. From this it follows that the observance of the natural sterile periods may be lawful, from the moral viewpoint: and it is lawful in the conditions mentioned.

Pope Pius XI, Casti Connubii (1930)

Nor are those considered as acting against nature who in the married state use their right in the proper manner although on account of natural reasons either of time or of certain defects, new life cannot be brought forth.

Pope John Paul II, Familiaris Consortio, no. 32

When, by means of recourse to periods of infertility, the couple respect the inseparable connection between the unitive and procreative meanings of human sexuality, they are acting as “ministers” of God’s plan and benefit from their sexuality according to the original dynamism of total self-giving, without manipulation or alteration.

Pope John Paul II, Evangelium Vitae, no. 97

It is precisely this respect which makes legitimate, at the service of responsible procreation, the use of natural methods of regulating fertility.

St. John Chrysostom, commenting on 1 Corinthians 7 in his Homily 19 on First Corinthians, explains that St. Paul does not say simply that they may abstain from sexual intimacy, but that they are to do so by agreement and for a time. Doing so does not deprive marriage of its honor, but he allows this for prayer.

St. Augustine affirms the same principle in his work On the Good of Marriage explaining that spouses may sometimes abstain from marital intimacy by mutual consent, to devote themselves to prayer, and that doing so is not contrary to the goods of marriage, but rather in harmony with them (see sections 6-11).

St. Thomas Aquinas and Infertile Marital Intercourse

More than seven centuries ago, St. Thomas Aquinas directly addressed and rejected the claim that marital intercourse becomes unlawful simply because conception cannot occur. His teaching is unambiguous.

The marriage act is directed primarily to the begetting of children; but it has a secondary end, which is the mutual fidelity of the spouses, and also the remedy of concupiscence. Hence, if it be impossible for generation to result, the marriage act is not on that account rendered unlawful.
Summa Theologiae, Supplement, q. 49, a. 5, ad 2

If a man know that his wife is barren, or if she be past the age of childbearing, it is not a sin for him to use the marriage act, because he does not act against the good of offspring, since he does nothing to prevent conception, but only makes use of marriage as it is.
Summa Theologiae, Supplement, q. 49, a. 3

St. Thomas Aquinas says nothing negative about periodic continence by married couples for the purpose of spacing children. In fact, he does not address that issue at all, even when discussing temporary abstinence within marriage for spiritual reasons (see Summa Theologiae, Supplement, questions 41–49). He draws on St. Augustine, who teaches that procreation is marriage’s primary end, and permits temporary abstinence by mutual consent for prayer in accordance with St. Paul in 1 Corinthians 7:5.

While St. Thomas holds that sexual intercourse known to be permanently infertile may be venially sinful if motivated purely by pleasure, he neither condemns nor even mentions timing of marital relations to naturally infertile phases. Note that such biological knowledge did not exist in his time. (See Summa Theologiae, Supplement, Question 49, especially articles 5–6. See also the entire Supplement, Questions 41–68, for the absence of any discussion of periodic continence for the purpose of spacing births. He reminds us that marital intercourse engaged in solely for pleasure rather than for offspring or rendering the marital debt, is at least venially sinful (see Summa Theologiae, Supplement, q. 49, a. 6; q. 49, a. 5, ad 2).

Dominic Prümmer, O.P.

The use of marriage during the naturally infertile periods is not illicit, since nothing is done to impede or pervert the act itself. The moral evil of contraception consists in the positive frustration of the generative power of the marital act.

John C. Ford, SJ, and Gerald Kelly, SJ

Recourse to the infertile periods involves no interference with the natural structure of the marital act. The act, when it occurs, remains fully natural, even though conception is not intended.

Germain Grisez

Choosing not to engage in intercourse at certain times does not render the marital act infertile. It simply refrains from the act. Therefore periodic abstinence differs in kind, not merely in degree, from contraception.

Servais Pinckaers, O.P.

To abstain from an act is not to falsify it. Moral evil arises when one acts against the meaning of the act itself, not when one freely chooses not to act.

Janet E. Smith

NFP doesn’t say no to God in His procreative act. It treasures a woman’s fertility and it enhances, not alienates, the relationship between spouses. It is not subject to the same objections as contraception. (Transcript of Janet E. Smith’s talk “Contraception: Why Not?” (1993), University of Notre Dame. Full text: https://www3.nd.edu/~afreddos/courses/264/contraception-whynot.htm

The Fundamental Moral Distinction

Contraception involves engaging in the marital act while deliberately robbing it of its procreative meaning and power. NFP involves abstaining from the marital act during fertile periods for a legitimate reason. Avoiding the use of a good thing is not the same as abusing that good thing. NFP is not contraception, and the Church has never taught otherwise.

Appendix: Recommended Reading

St. Augustine
On the Good of Marriage and On Marriage and Concupiscence. See Marriage and Virginity (The Works of Saint Augustine: A Translation for the 21st Century, Part I, vol. 9; New City Press, 1999), see also the Christian Classics Ethereal Library: https://ccel.org/ccel/augustine/doctrinal.html

Dominic Prümmer, O.P.
Handbook of Moral Theology (Roman Catholic Books).

John C. Ford, S.J., and Gerald Kelly, S.J.
Contemporary Moral Theology, Vol. II: Marriage Questions.

Germain Grisez
Christian Moral Principles and Living a Christian Life.

Servais Pinckaers, O.P.
The Sources of Christian Ethics.

St. Thomas Aquinas
Summa Theologiae, Supplement, Questions 41–49 (On Marriage).

Charles D. Provan
The Bible and Birth Control, Monongahela, PA: Zimmer Printing, 1989.)

National Catholic Bioethics Center (NCBC)
www.ncbcenter.org, Making Sense of Bioethics
https://www.ncbcenter.org/making-sense-of-bioethics-cms/tag/Natural%2BFamily%2BPlanning%2B%28NFP%29

https://www.ncbcenter.org/resources-and-statements-cms/tag/Natural%2BFamily%2BPlanning%2B%28NFP%29

Video lecture series by Fr. Tadeusz Pacholczyk, Director of Education at the NCBC
https://www.ncbcenter.org/seeking-the-moral-path-video-lectures-by-fr-tad

Copyright © 2025 Patrick Madrid. All rights reserved. All text, images, and other original content are the property of the author.

I hope you enjoy my articles here. If so, please tap the Share button above to post any of them on X or Instagram or to send it to someone who might be interested in it. And if you enjoy thoughtful, friendly, faith related content, you’ll appreciate my daily program on Relevant Radio. Listen here or get the free Relevant Radio app.

1. See Familiaris Consortio no. 32 (“In the light of the experience of many couples and of the data provided by the different human sciences, theological reflection is able to perceive and is called to study further the difference, both anthropological and moral, between contraception and recourse to the rhythm of the cycle: it is a difference which is much wider and deeper than is usually thought, one which involves in the final analysis two irreconcilable concepts of the human person and of human sexuality”) and CCC 1753-1756.

2. For Pope John Paul II’s use of the term “contraceptive mentality” see Evangelium Vitae, 13; see also Catechism of the Catholic Church, 2368.