Church Teaching on Rhythm Method & Natural Family Planning

  • Posted December 28, 2018

We know that artificial contraceptives are mortally sinful. The Catholic Church teaches that one who uses these contraceptives, and dies with this stain of sin on their soul will go to hell. One can not be a Catholic and reject this. However, what of the question of Natural Family Planning otherwise known as the Rhythm Method?? Is Natural Family Planning sinful?

This turns out to be a misunderstood question, so here is what the theologians and the Church says…

On the Question of Natural Family Planning

by the Most Reverend Mark. A. Pivarunas, CMRI

The issue of Natural Family Planning is certainly one that has been misunderstood and misrepresented. On one hand, there are some who erroneously believe that NFP can be practiced indiscriminately without the necessary conditions listed by Pope Pius XII (i.e. a serious reason, mutual consent, and morally possibly) and on the other, there are some who condemn entirely the practice of NFP, regardless of serious necessity. It would be better, of course, if this delicate matter were treated in private — with married couples and those preparing for marriage. Because it has become so public, however, it is necessary to answer the important question: “What DOES the Catholic Church really teach on this moral issue?” You will find the answer well explained by His Excellency. Once again, let this also serve as a reminder to all couples that a sufficiently grave reason is necessary to make use of Natural Family Planning.


February 18, 2002

Dear N.,

Praised be Jesus and Mary!

Thank you for your recent letter on the topic of “rhythm” and I welcome the opportunity to set this matter straight.

Not unlike the Protestants who misinterpret Sacred Scripture, there are some traditional Catholics who misunderstand past teachings of the Catholic Church and thereby arrive at erroneous conclusions. I believe that this is certainly the situation with “rhythm.”

Consider the following points:

1) The very concept of “rhythm” was first considered by the Catholic Church in 1853. The Bishop of Amiens, France, submitted the following question to the Sacred Penitentiary:

“Certain married couples, relying on the opinion of learned physicians, are convinced that there are several days each month in which conception cannot occur. Are those who do not use the marriage right except on such days to be disturbed, especially if they have legitimate reasons for abstaining from the conjugal act?”

On March 2, 1853, the Sacred Penitentiary (during the reign of Pope Pius IX) answered as follows:

“Those spoken of in the request are not to be disturbed, providing that they do nothing to impede conception.”

a) Please note: “providing that they do nothing to impede conception.” When married couples practice rhythm, they do not do anything unnatural in the act itself.

In Medical Ethics by Fr. Charles J. McFadden, O.S.A, Ph.D., we read:

“In the use of the safe period, married persons do not interfere in any way with the operation of nature. Their marital relationship is carried out in the strictly natural manner… No unnatural action is committed by those who exercise their marital rights in a truly natural manner during the safe period… In marriage, both parties acquire mutual permanent rights to marital relationship. This fact indicates that they have the right at all times. Generally speaking, however, they do not have the obligation to exercise their rights at any specific time.”

b) Conception certainly can still take place even when couples practice rhythm. In Marriage Guidance by Fr. Edwin F. Healy, S.J., S.T.D., we find:

“Rhythm cannot be looked upon as a certain method of avoiding offspring… The reasons for lack of certainty are: (1) It is difficult to be sure of the strict regularity of a particular woman’s ovulation periods. (2) Fertilization at times occurs during the periods which this theory regards as absolutely sterile.”

2) Another reference to rhythm appeared in 1880. Fr. Le Conte submitted the following questions to the Sacred Penitentiary:

“Whether married couples may have intercourse during such sterile periods without committing mortal or venial sin?”

“Whether the confessor may suggest such a procedure either to the wife who detests the onanism of her husband but cannot correct him, or to either spouse who shrinks from having numerous children?”

The response of the Sacred Penitentiary (during the reign of Pope Leo XIII), dated June 16, 1880, was:

“Married couples who use their marriage right in the aforesaid manner are not to be disturbed, and the confessor may suggest the opinion in question, cautiously, however, to those married people whom he has tried in vain by other means to dissuade from the detestable crime of onanism.”

a) Please note that onanism and rhythm are two different things. In Medico-Moral Problems, Fr. Gerard Kelly, S.J., explained:

“The Church teaches that contraception is a sin because it means doing what is evil. It is not the same with rhythm. Those who practice the rhythm do nothing evil. They simply omit doing something good — that is, they abstain from intercourse at the time when it might be fertile. Therefore, the morality of using rhythm must be judged in the same way as other omissions: if the abstinence from intercourse is a neglect of duty, it is sinful; if it does not imply a neglect of duty, it is not sinful.”

b) In The Administration of the Sacraments by Fr. Nicholas Halligan, O.P., there is yet another reference to the morality of rhythm:

“As regards the conjugal act spouses are free to choose whatever time they wish to use their marital rights or also to abstain by mutual consent. Thus they are not obliged to perform this act only during the fertile period, neither are they obliged to refrain during the sterile period.

“God has endowed the nature of woman with both periods. Deliberately to limit the use of marital relations exclusively to the sterile periods in order to avoid conception (i.e., to practice periodic continence or rhythm) is, according to the common teaching of theologians, morally lawful in actual practice if there is mutual consent, sufficient reason and due safeguards against attendant dangers. “It is also common teaching that this practice of family limitation without good and sufficient reason involves a degree of moral fault. This fault certainly could be mortal if serious injustice is done or there exists grave danger of incontinence, divorce, serious family discord, etc.”

c) Furthermore, the above responses of the Sacred Penitentiary (which are quoted in sections 1 and 2 of this letter) were the moral guidelines for the theologians long before Pope Pius XII addressed this issue. As we read in Handbook of Moral Theologyby Fr. Dominic Prummer, O.P.:

“To make use of the so-called safe period (i.e., to refrain from the conjugal act during the period when the woman is fertile) has been declared lawful by the Sacred Penitentiary, but it is not a certain means of preventing conception, since there is no infallible way of determining the safe period.”

3) You misinterpret Pope Pius XI in his encyclical Casti Connubii when he teaches:

“Since, moreover, the conjugal act by its very nature is destined for the generating of offspring, those who in the exercise of it deliberately deprive it of its natural force and power, act contrary to nature, and do something that is shameful and intrinsically bad.”

a) Married couples do not “deprive it [the marriage act] of its natural force and power” with the practice of rhythm because conception is still possible.

b) The footnotes in Denzinger on this quote of Pope Pius XI refer to the sinful practice of onanism — whether by interrupted copulation or by artificial instruments. There is no mention of rhythm at all.

4) It is also incorrect to say that Pope Pius XI had not referred to rhythm in his encyclical when he taught:

“Nor are those married couples to be considered as acting against the order of nature who make use of their right in the proper, natural way, even though through natural causes either of time or of certain defects, new life cannot thence result.”

a) In Moral Theology by Fr. John C. Ford, S.J., and Fr. Gerard Kelly, S.J., we find an interesting answer to those who would doubt whether this quote of Pope Pius XI was referring to rhythm:

“The fact that the licit use of the sterile period was already at that time a commonplace among theologians, the fact that the phrase ‘through natural reasons… of time’ was used, rather than ‘reasons of age’ or some similar expression, and the fact that the immediate context of the encyclical itself was concern for the difficulties of married people tempted to onanism — all these considerations convinced the great majority of theologians that Pius XI was here referring to the permissible use of the sterile periods as a means of avoiding conception. Pius XII, we may mention here, explicitly confirmed this view in 1958 (Address to Hematologists, 12 Sept. 1958, A.A.S., 50 [1958] 736), thus dispelling what little doubt had existed on this point.”

b) Thus whatever interpretation you may apply to Pope Pius XI’s “Nor are those married couples…”, Pope Pius XII has already confirmed what his predecessor meant.

5) For those who would belittle Pope Pius XII’s teaching on the morality of rhythm on the score that he addressed only mid-wives and nurses, let them realize that this address is contained in the Acta Apostolicae Sedis (the official Acts of the Apostolic See).

Refer to: Acta Apostolicae Sedis 43 (1951) 845-46. On two other occasions, Pope Pius XII reiterated this same teaching and these also can be found in the Acta Apostolicae Sedis 43 (1953) 855-60 at 859 and Acta Apostolicae Sedis 50 (1958) 732-48, at 736.

a) It is interesting to note that Fr. Paul Nau, O.S.B., in his article on the “Ordinary Universal Teaching Authority of the Pope” explicitly referred to this teaching of Pope Pius XII on rhythm as an example of an allocution used to promulgate a teaching to the universal Church:

“The pope can use other means for worldwide communication. With extreme care for tact and delicacy, Pope Pius XII has chosen, in speaking of certain more delicate problems of conjugal chastity, to confine his remarks to an audience of doctors, nurses and technicians.

“A good example of this is the allocution Pius XII gave in 1951 to the midwives. Certainly an allocution is not the most solemn means of teaching at the pope’s disposal, but it is just as certain that the pope did intend to teach quite authoritatively in this case.

“There is no question but that such a discourse was intended to have, and in fact has had, a much wider audience than that of his immediate hearers. The same is true of letters and allocutions directed to bishops. As Supreme Pastor teaching other pastors, the pope here exercises a magisterium that is virtually universal. The audiences in these cases are like sounding boards for greater resonance and wider acceptance of the papal teaching.

“When considering such widespread resonance and acceptance of teachings in the Church, we cannot overlook the help of the Holy Spirit given personally to the Successor of Peter. This assistance is meant to prevent the Pastor from leading the flock astray. The pope is endowed with infallibility because he must direct the Church which Christ promised would be preserved from all error till the end of time.

“We can expect the help of the Holy Spirit on any occasion to be in direct proportion to the impact the pope’s words have on the faith of the universal Church. Whatever is accepted throughout the Church must be true, and the greater acceptance a papal declaration finds, the greater reason we have for accepting it as part of the Catholic faith.”

6) It is important to mention that Pope Pius XII placed a condition on the use of rhythm:

“Consequently to embrace the state of matrimony, to use continually the faculty proper to it, and in it alone, and on the other hand to withdraw always and deliberately, without a grave motive, from its primary duty, would be to sin against the very meaning of conjugal life” (A.A.S., 43 [1951] 845-846).

7) Well before Vatican II, moral theologians consistently reiterated the teaching of the Sacred Penitentiary and Pope Pius XII on the morality of rhythm.

It is difficult to comprehend how anyone can claim that the pope, the Sacred Penitentiary, and moral theologians have been in error on this issue for some 150 years and that laity have now figured it out.

With an assurance of my prayers, I remain

Sincerely in Christ,
Most Rev. Mark A. Pivarunas, CMRI

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