Some Catholics reject NFP altogether, since they view it as essentially no different than contraception. But the Magisterium definitively teaches that contraception is intrinsically evil, and that NFP is not. Natural family planning uses periodic abstinence to reduce the likelihood of conception. So NFP cannot be considered immoral on the same basis as contraception. For between periods of abstinence, NFP allows each and every marital sexual act to be procreative, whereas contraception deprives sexual acts of their procreative meaning.
Is it moral for spouses to periodically abstain from marital relations? The morality of NFP is based on the teaching that a husband and wife may cease from marital relations, for a determinate period of time, for a variety of different reasons. This principle was taught infallibly by an Ecumenical Council.
The Council of Trent: “If anyone says, that the Church errs, in that she declares that, for many causes, a separation may take place between husband and wife, in regard of bed, or in regard of cohabitation, for a determinate or for an indeterminate period; let him be anathema.”
This teaching of Trent includes periodic abstinence (separation…in regard of bed…for a determinate…period) as well as other types of separation. Therefore, the rejection of natural family planning on the basis of a claim that the husband and wife may not periodically abstain from marital relations for a determinate period of time is a heresy against the Catholic Faith.
Periodic abstinence from marital relations is moral. And NFP does not have the evil moral object of depriving the marital sexual act of the procreative meaning, as contraception does. But what is the good moral object of NFP? The act of deciding to refrain from marital relations periodically has the good moral object of responsible use of human procreation.
So the remaining question is whether the spouses may use NFP in any circumstance for any reason, or only in certain circumstances for certain reasons. The basic teaching of the Magisterium on ethics provides a clear answer. As Veritatis Splendor instructs us, in order to be moral, all three fonts of morality must be good:
2. moral object
But we have already determined that NFP has a good moral object. So for the use of NFP in particular cases to be moral, a good intention (motive, purpose, reason) and good circumstances are needed.
Must the intention or reason for choosing NFP be grave, or is a just reason sufficient?
“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.” (Humanae Vitae, n. 16).
“But it is equally true that it is exclusively in the former case that husband and wife are ready to abstain from intercourse during the fertile period as often as for reasonable motives the birth of another child is not desirable. And when the infertile period recurs, they use their married intimacy to express their mutual love and safeguard their fidelity toward one another. In doing this they certainly give proof of a true and authentic love.” (Humanae Vitae, n. 16).
Humanae Vitae teaches that “well-grounded reasons” or “reasonable motives” are sufficient to make the font of intention good in the use of NFP. A grave reason is NOT needed in order to use NFP to space births (to decrease the total number of children that would otherwise be anticipated).
Pontifical Council For The Family: “However, profoundly different from any contraceptive practice is the behavior of married couples, who, always remaining fundamentally open to the gift of life, live their intimacy only in the unfruitful periods, when they are led to this course by serious motives of responsible parenthood. This is true both from the anthropological and moral points of view, because it is rooted in a different conception of the person and of sexuality. The witness of couples who for years have lived in harmony with the plan of the Creator, and who, for proportionately serious reasons, licitly use the methods rightly called ‘natural,’ confirms that it is possible for spouses to live the demands of chastity and of married life with common accord and full self-giving.” (Pontifical Council for the Family, Vademecum ['Go with me'] for Confessors concerning some Aspects of the Morality of Conjugal Life, n. 2-6.)
The Holy See teaches that “serious motives,” and more specifically “proportionately serious reasons,” are needed in order to use NFP to avoid, or to decrease the likelihood of, conception. The reason or motive for using NFP cannot be light or trivial, since the responsible use of the procreative faculty is a serious matter. However, the motives also need not be particularly grave or unusual. All spouses are called to exercise responsible parenthood.
Finally, we come to a consideration of the third font, circumstances. If the intention is good, and the couple are using NFP, which has a good moral object, then only the circumstances remains to be good for the act to be entirely moral. The font of circumstances is bad (making the act immoral) whenever the bad consequences morally outweigh the good consequences, as these consequences can be reasonably anticipated at the time that the act is chosen.
Now since children are the highest good of marriage, the use of NFP has more bad consequences when it is used more strictly, to avoid all conception, and less bad consequences when it is used only to space out births. And this is why the Holy See speaks about proportionately serious reasons. The good consequences must be proportionate to the bad consequences for any act to be moral. A very strict use of NFP, in an attempt to avoid all conception, by a couple with no children, requires grave circumstances, such as the likelihood of serious birth defects in the child, or of a serious danger to the life of the mother. Whereas, if the couple is already blessed with a number of children, the strict use of NFP requires a lesser degree of gravity for its use, since the bad consequence of a childless marriage is not at issue.
Any bad intention makes an act immoral. Any bad moral object makes an act intrinsically evil and always immoral. But proportionality applies to the circumstances. For circumstances vary greatly, and many good and bad consequences to any act are possible, some with more moral weight and others with less. So this evaluation of the circumstances is a matter of degree. All of the complex circumstances of the married life of the spouses should be considered, with all of the reasonably anticipated good and bad consequences. Then if the use of NFP has more good consequences than bad consequences, the font called circumstances is good.
When all three fonts of morality are good, the act is moral.
Ronald L. Conte Jr.
Roman Catholic theologian and Bible translator
portions of this post were taken from my book:
The Catechism of Catholic Ethics