WHY THE TRUE CATHOLIC REJECTS NATURAL FAMILY PLANNING

Something to defend!

The Mission of the Most Holy Trinity is an authentic defender of the Holy Catholic family, seeing it as essential to the preservation of the Faith and the sanctification of souls. The Catholic family is the domestic church, established by God through the sacrament of Matrimony and ordered toward the procreation and Christian formation of children. The Church teaches that the family is the foundation of both Church and society.

Despite the clear magisterial teachings on Matrimony and the family, many, even in traditional Catholic circles, promote and teach the contraceptive method called "Natural Family Planning (NFP)." Therefore, as faithful children of our Holy Mother Church we must wage war for this institution and defend it against those who oppose its purpose, even if it means we will face negative repercussions.

A moral question

Natural Family Planning (NFP) is often presented as a moral alternative to artificial contraception. It is commonly defended on the grounds that it merely cooperates with nature rather than frustrating it. However, when examined through the lens of true Catholic moral theology, papal teaching, and the perennial understanding of marriage, it becomes evident that the modern promotion and habitual use of NFP shares the same contraceptive mentality condemned by the Church.

The question is not whether biological rhythms exist—they certainly do—but whether the deliberate and habitual use of infertile periods with the precise intention of avoiding offspring is compatible with the ends of marriage as taught infallibly by the Church.

I. The Primary End of Marriage:

Procreation

The Catholic Church teaches that the primary end of marriage is the procreation and education of children.

This is settled doctrine:

"The primary end of marriage is the procreation and education of offspring; the secondary end is mutual assistance and a remedy for concupiscence” (1917 Code of Canon Law, canon 1013 §1).

“The primary end of marriage is the procreation and education of children; the secondary end is mutual help and a remedy for concupiscence" (Pope Pius XI, Casti Connubii (1930).

This hierarchy of ends was consistently taught by the Fathers, Scholastics, and Popes prior to Vatican II. Any marital act that is positively directed against the primary end, even if it avoids artificial means, is surely guilty of serious moral disorder and sin. For this reason someone cannot enter validly into marriage knowing that they are infertile and unable to bare children, despite natural nature of the condition.

II. A Comparison of Acting Against the End

Catholic moral theology judges human acts according to their object, intention, and end. An act becomes morally disordered when it is positively directed against the natural end for which a faculty was given, even if the external form of the act is preserved. This principle is consistently applied across moral theology and is not unique to marriage.

Below are two examples:

1. Eating Deliberately Excluding Nourishment

The natural end of eating is nourishment and the preservation of life. When a person eats while deliberately intending to exclude nourishment—for example, by inducing vomiting—the act becomes gravely disordered. The individual still eats food; no poison is introduced, and the physical process of eating remains intact. Yet the act is sinful because the eater wills the pleasure of eating while rejecting its natural end.

The moral disorder lies not in the food itself, but in the intention to frustrate nourishment. Notice the emphasis on intention since even if the person did not induce vomiting but intended to while eating the act has been morally compromised. Acts therefore are judged by its end, not merely by its outward form.

2. Speech Deliberately Ordered Against Truth

The natural end of speech is the communication of truth. When speech is deliberately used to deceive, the act becomes morally disordered, even though no violence is done to language itself. Words are spoken correctly, grammar is preserved, and communication occurs; nevertheless, lying is intrinsically sinful because it perverts the purpose of speech.

As St. Augustine and St. Thomas teach, speech ordered against truth contradicts the nature of the faculty itself. The moral species of the act is determined by the intention to deceive.

Application to the Marital Act

In the same way, the marital act has a natural and primary end: the procreation of children. When spouses engage in the marital act while deliberately intending to exclude this end, the act becomes morally disordered, even if no artificial means are used. As with eating without nourishment or speech without truth, the disorder arises from the willful rejection of the act’s proper end, not from the external mechanics.

Thus, any marital act positively directed against its primary end participates in the same moral principle long recognized by Catholic theology: to use a faculty while rejecting its God-given purpose is to act against nature and against the moral law

III. Intention Determines the Moral Species of the Act

Traditional Catholic moral theology teaches that the moral species of an act is determined primarily by its object and intention.

St. Thomas Aquinas teaches:

“An action takes its species from the object, and from the end intended.”

— Summa Theologiae, I–II, q.18, a.6

When spouses deliberately choose to engage in marital relations only during infertile periods, not for grave reasons, but as a regular way of avoiding children, the intention is identical to contraception: namely, to enjoy the marital act while excluding its procreative meaning.

The absence of a physical barrier does not change the moral reality of the intention.

IV. Pope Pius XI and the Condemnation of Contraceptive Mentality

Pope Pius XI condemned not only specific methods, but the principle of separating sex from procreation:

“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.”

— Casti Connubii, n. 54

While rhythm-based abstinence is not explicitly named here, the principle is clear: marital acts deliberately rendered sterile in intention violatethe natural law.

The pope further warns against placing personal convenience above God’s design:

“Those who in exercising it deliberately frustrate its natural power and purpose sin against nature and commit a deed which is shameful and intrinsically vicious.”

V. Pope Pius XII: A Narrow and Often Abused Exception

Defenders of NFP often appeal to Pope Pius XII’s 1951 address to midwives. However, this address does not endorse NFP as a lifestyle, but allows periodic continence only for grave reasons (e.g., serious health risks, extreme poverty).

“Serious motives, such as those which not rarely arise from medical, eugenic, economic and social conditions, may exempt husband and wife from the positive and obligatory debt for a long time, even for the entire duration of the marriage.”

— Pius XII, Address to Midwives, 1951

This is not a blanket approval. It presupposes:

• Grave reasons

• A spirit of sacrifice

• Openness to life in principle

The modern NFP movement, however, promotes routine child-avoidance, often for reasons of comfort, lifestyle, or personal preference—reasons explicitly rejected by the tradition.

When we look back upon the lives of large and holy Catholic families—many of whom lived in genuine poverty and uncertainty—we can scarcely place ourselves in a state of necessity grave enough to justify the deliberate avoidance of children. The saints did not calculate their families according to comfort, financial security, or personal preference. They embraced sacrifice, trusting that God would provide what was necessary for those lives He Himself willed into existence. For the Catholic, it is God who plans the family, not man; to claim that we must first secure every condition before welcoming life is not prudence, but a failure of trust in Divine Providence.

Surely Pope Pius XII would not have approved of the way NFP is promoted today as "Catholic contraception." We cannot accept such a notion!

VI. The Sin of Onan and the Eternal Principle

Scripture itself reveals God’s judgment on contraceptive intent:

“And Onan knew that the seed should not be his; and it came to pass, when he went in unto his brother’s wife, that he spilled it on the ground, lest that he should give seed to his brother. And what he did displeased the Lord: wherefore He slew him.”

— Genesis 38:9–10 (Douay-Rheims Bible)

The Church has consistently taught that Onan was punished not merely for disobedience, but for the deliberate frustration of generation.

NFP used with contraceptive intent differs only in method, not in moral object.

VII. The Fruits of NFP and the Contraceptive Mentality

Our Lord teaches:

“By their fruits you shall know them.” (Matthew 7:16)

The widespread promotion of NFP has coincided with:

• Smaller families

• Delayed openness to life

• The normalization of child-avoidance

• A loss of sacrificial marital spirituality

These are the same fruits produced by artificial contraception.

Conclusion: NFP and the Evidence of Two Religions

The Catholic Church has always taught that marriage is ordered primarily toward the procreation and education of children, and that any marital act deliberately directed against this end is morally disordered.

The post–Vatican II (Novus Ordo) paradigm represents a decisive break from this moral vision. What was once reluctantly tolerated is now actively promoted. What was once judged by objective ends and intention is now evaluated primarily by method. Child-avoidance, formerly treated as a moral danger, is now normalized and encouraged under the banner of “responsible parenthood.”

This is not a difference of emphasis, discipline, or pastoral approach. It is a difference of moral theology.

A religion that condemns contraceptive intent cannot simultaneously build structures to facilitate it. A theology rooted in sacrifice, providence, and objective ends cannot be reconciled with one centered on calculation, personal discernment, and fertility management.

This divergence over NFP therefore stands as additional evidence—among many others—that the Novus Ordo system operates according to a moral framework distinct from that of the Catholic Church as it existed and taught prior to Vatican II.

The Catholic religion remains what it has always been. The question is not whether Catholic teaching has changed—but which religion one is following.

Semper, ubique, et ab omnibus