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"It is through conscience that human beings see and recognize the demands of the divine law. They are bound to follow their conscience faithfully in everything they do."
Religious Liberty, no 2.


A History of Its Treatment by the Catholic Theologians and Canonists

Enlarged Edition

John T. Noonan, Jr.

The Belknap Press of HARVARD UNIVERSITY PRESS Cambridge, Massachusetts, and London, England 1986



Unquestionably the most celebrated and the most debated invocation and interpretation of natural law by the Church in modern times have been the teaching of the magisterium on the steps which may, and the steps which may not, be taken to rule human fertility. Two famous documents, Gaudium et spes of the Second Vatican Council and Humanae vitae of Paul VI, embody this teaching. What do they prohibit, what do they permit, what do they encourage, what do they make mandatory? To what extent are they affirmations of earlier doctrine? To what extent do they represent the development of doctrine and, in particular, development in understanding of the natural law? To what extent do they call for further investigation, clarification, or development?

The time for debate over doctrine itself is past. The teaching of Humanae vitae is a given of Catholic doctrine. The time now is to understand the encyclical and to answer questions within its framework.

First. Gaudium et spes and Humanae vitae must be read together. Gaudium et spes specifically refers to certain questions regarding the regulation of procreation which have been reserved for judgment by the Pope. Humanae vitae builds upon the conciliar foundation; the Pope speaks out of the conciliar context.(1) It has been asserted that the two documents are discordant.(2) But this assertion has been sustained principally by contrasting a draft version of Gaudium et spes with Humanae vitae. The final text of Gaudium et spes, modified as it had been at the insistence of Paul VI, is, after all, the only authentic voice of the Council. The essential unity of Council and Pope in Gandium et spes and the Pope in Humanae vitae has been ably argued by Pope John Paul II when as Cardinal Wojtyla he expounded the connection between the two, the one “stressing the christological and sacramental aspect of marriage,” the other more “strictly theological and systematic.”(3) Paul VI, who as Pontiff had confirmed the teachings of the Council in 1965, did not repudiate them, but incorporated them in his own encyclical of 1968. The bishops who had given Gaudium et spes to the world in 1965 did not reject the Pope’s elaboration of it in 1968. To set Pope against Council, document against document, is a sure way to polemical misunderstanding of both. They stand together.(4)

Second. The foundation of the teaching is the human person. As Cardinal Wojtyla was to put it, “The central value, upon which other values in love depend, is the value of the human person. It is to the human person that basic responsibility refers.”(5) Thus, the Second Vatican Council, speaking of married love in Gaudium et spes, declares, “That love, an eminently human one since it is directed from one person to another through the affection of the will, embraces the good of the whole person. . . .”(6) Biological laws which “pertain to the human person,” Paul VI teaches, are those which reason apprehends,(7) and, he observes, conjugal love is “a special form of personal friendship.”(8) It is the unique union of two persons by human love that is the starting point for the Council and the Pope. The reason for this starting point is that married love takes its source from God, Who is Love, and whose love is at once personal and paternal.(9)

Third. The choice of this foundation is a development of doctrine. True, two of the three traditional values of marriage—fides and sacramentum— rested on this foundation. Fidelity in marriage was a requirement which always acknowledged, at least implicitly, the uniqueness of two persons in marriage for each other. Indissolubility, based ultimately on the paradigm of Christ’s union with his Church, was peculiarly a recognition of a personal element transcending the changes of animal existence. But not before, in any such authoritative document of the magisterium, had the personal character of conjugal love been made the starting point for teaching on the significance of conjugal intercourse and its relation to procreation. The first argumentation against the unnaturalness of contraception rested on its contradiction of the natural purpose of the genital organs and the genital act.(10) Such natural biological purpose is common to men and animals. The new starting point had been sketched in the work of Herbert Dorns in 1936.(11) It is proper to human beings. If some action is condemned, it is not because it violates animal biology, but because it is contrary to something in the special relation of two persons united by marriage encountering each other in conjugal intercourse.

Fourth. The Council teaches that one purpose of conjugal intercourse is the expression of conjugal love. Referring to this love “simultaneously joining the human and the divine,” the Council declares: “This love is uniquely expressed and perfected by the marital act itself.”(12) Paul VI teaches that even when conjugal coupling is by nature sterile, its finality “toward the signifying and strengthening of the union of the spouses does not cease.”(13) So fundamental is this signifying that, Paul VI teaches, a matrimonial act which is imposed upon one spouse is “no true act of love,” and it is therefore contrary to the moral order.(14)

Fifth. That the expression of conjugal love is a purpose of conjugal intercourse is a development of doctrine. True, in teaching as old as St. Paul, the centrality of conjugal intercourse in marriage had been insisted upon (1 Cor. 7, 3-6); but the Pauline phrasing and emphasis had been in terms of obligation. Expression of love as a purpose of conjugal intercourse had been a theological opinion of the nineteenth century.(15) Never before had it been taught by an ecumenical council or by a papal encyclical. Never before had such high authorities so nuanced and qualified the Pauline teaching on the marital debt that the right to conjugal intercourse was illuminated by the requirements of mutual love. Never before had a Pope made clear that the imposition of a matrimonial act could be a breach of the moral order.

Sixth. Both the Pope and Council place the locus for responsibility for the number of children in the decision of the married couple. In solemn terms, the Council affirms that, after taking account of their own welfare and that of their children already born or foreseen, and the material and spiritual conditions of the times and their own state in life and the welfare of the family, community, temporal society and the Church herself, the two spouses will make a judgment: “This judgment ultimately the spouses themselves must make before God.”(16) In harmony with this teaching, Paul VI declares that parenthood is to be “conscious.” Such parenthood, he points out, means the control of innate impulses by the use of reason and will. It means observance of “the physical, economic, and psychological conditions,” and, in the light of these conditions, a decision to have more children or “for a definite or indefinite time not to bear a child.”(17) Conscious parenthood, he observes finally, requires observance of the objective moral order. In this presentation of parental responsibility, no higher gift is shared by a married couple than their right and duty to imitate the action of God in deciding when to bring new life upon the earth and as pro-creators to act in collaboration with the Creator in producing new images of God.(18)

Seventh. Emphasis upon “conscious parenthood” and the sole responsibility for parenthood vested in the couple is a development of doctrine. True, the entire Christian tradition had been one of “responsible parenthood” in that Christian teaching has never been irresponsibly philoprogenitive or proclaimed “the more, the better.” In its radical insistence that procreation be carried out only in marriage, the doctrine had been opposed to the mindless multiplication of offspring. In its permission of marriage for the old and the sterile the Church had not sought to maximize fertility. In constantly teaching that the bonum prolis meant not mere physical offspring but children “to be religiously educated,” the Church affirmed a preference for the spiritual quality of the persons procreated over purely physical increase.(19) Nonetheless, the emphasis on the locus of decision and the ultimate responsibility of the couple for the decision was new, an advance in doctrine underlining the duty of the procreators to act responsibly in procreating.

Eighth. Both Council and Pope taught that there were ways of exercising this responsibility which were contrary to the teaching of the Church. These methods included sterilization and abortion. The Council further taught that “objective criteria taken from the nature of the person and his acts” must determine the morality of any method in such a way as to preserve “the full meaning of mutual gift and human procreation in the context of true love.”(20) The Pope in a central passage of Humanae vitae declared, “Where conjugal intercourse is foreseen or carried out or brought to its natural results, there must be rejected every act whatsoever which, as an end to be accomplished or as a means to be applied, intends that procreation be impeded.”(21) Again, in the encyclical he taught that there was “an indissoluble nexus, established by God, which it is not lawful for man by his own will to break, between the significance of union and the significance of procreation which inhere together in the conjugal act.”(22) In these terms the Pope specifically taught that certain ways of robbing conjugal coitus of fertility were unlawful and unnatural. The Pope did not employ the com-prehensive, popular, and imprecise term “contraception,” but clearly contraception in some sense was embraced by his condemnation.

Ninth. In teaching that certain methods of exercising responsibility in conjugal intercourse were contrary to divine law, the Council reaffirmed a teaching of the Church as old as the passage in Galatians 5.20 that pharmakeia (the use of abortifacients, contraceptives) should not be practiced by the followers of Jesus.(23) In recent times this teaching had been summed up in Pius XI’s encyclical Casti connubii,(24) At the same time Paul VI advanced a new and distinct basis for the doctrine forbidding intervention which deliberately deprived a naturally fecund marital act of fecundity. This doctrine, he declares, “rested” on “the indissoluble bond between the significance of unity and the significance of procreation.” In declaring this to be the basis for the doctrine Paul VI showed that the basis of the law was not animal biology, but the symbolic meaning, rooted in biological rhythms, but graspable only by human intelligence and speaking only to rational beings. It is with particular reference to this central symbolic significance of the procreative-unitive act that the Pope says,“We think that the human beings of our age are most suited to see that this doctrine is consonant with human reason”(25)—that is, people of today are peculiarly suited to grasp symbolic significance.(26)

Respect for this symbolic significance, rooted in natural processes, is not set out as an arbitrary demand of the Church. The sign has not been capriciously selected. The natural oneness of procreation and love is interpreted by the Pope as the plan of the Creator. Man does not have unlimited power to modify this plan. He who keeps the laws governing generation acknowledges that “he is not the lord of the sources of life but rather the minister of the plan begun by the Creator.”(27) In this way respect for the symbol is united with respect for life. In this way the basic reason for the rule is that which a history of the teaching on contraception had identified as offering “an absolute bar to contraception because of its departure from the order established by God.”(28)

Tenth. That there are ways of exercising responsibility in procreation is implicit in Gaudium et spes and explicit in Humanae vitae. It is lawful, Paul VI proclaims, for spouses “to follow the natural rhythms immanent in the generative faculties by having marital intercourse in precisely those times which are empty for conception.”(29) If the spouses at such times which are “not fit for conception” engage in intercourse “to evidence mutual love and to keep the fidelity promised to each other,” they surely offer evidence “of a true and entirely righteous love.”(30) Physicians are encouraged by the Pope to establish a firm foundation for the regulation of offspring on the basis of such “observed natural rhythms.”

Eleventh. In this teaching, Paul VI develops what was briefly acknowledged by Pius XI in Casti connubii and enlarged upon in allocutions by Pius XII.(31) Humanae vitae is the fullest and most formal recognition of the right of married couples for just reasons deliberately to separate procreative purpose from marital intercourse by the choice of times when the natural rhythm of biology makes conception improbable. In these circumstances, the Pope declares, there is no breaking of the natural nexus of fertility and unity: the spouses “use the faculty given them by nature.”(32) The force of this distinction can only be grasped by seeing that the symbolic character of the procreative-unitive act rests on the natural rhythm. When the rhythm gives this unity, it is not for man to disrupt it. When the rhythm produces a lack of fecundity, there is no offense to the natural order in letting the act signify love alone. The stress on natural rhythm and the contrast between this rhythm and human intervention to produce sterility represent a clarification of doctrine.

Twelfth. The Council implies, and the Pope makes explicit, that it is lawful for the spouses to use “means necessary to cure diseases of the body, although an impediment to procreation thence arises, even though it has been foreseen, provided that on no account is this impediment directly intended.”(33) In short, therapeutic measures may be undertaken although a side effect is to affect fertility and produce temporary sterility. As long as the intention is to achieve normal health, the side effect on fertility does not prohibit the use of the therapeutic contraceptive. Such approval of indirectly contraceptive measures had been anticipated by Pius XII permitting them under the principle of double effect.(34) Humanae vitae, by implication, accepted the validity of appeal to this principle even in this area touching on the transmission of life.


The following has been established: Gaudium et spes and Humanae vitae are not in conflict. The teaching of both as to responsible parenthood and right ways of achieving it starts from consideration of the human person and requires objective criteria based on the nature of persons and their conjugal acts. The encyclical takes the natural rhythm of fecundity and infecundity as the basis for the symbolic human significance of conjugal acts in which fecundity accompanies the expression of love. In starting point and in insistence on the duty of responsible parenthood, Gaudium et spes and Humanae vitae are a development of doctrine. Are further clarifications needed? Is further development possible?

It would be surprising that the development of doctrine on the requirements of parenthood and conjugal love left wholly unaffected specific teaching which is dependent on these requirements. It would be equally surprising that a teaching of the Church as old as St. Paul’s Letter to the Galatians would be abandoned. It would finally be surprising that an issue which occasioned such doubt and study within the Church was completely resolved in one stroke. Paul VI was under no illusion on this score. He urged Catholic scholars to show that “there cannot be a true contradiction between the divine laws of transmitting life and of fostering authentic conjugal love.”(35) If this lack of contradiction is still to be demonstrated, there is an area in which clarification and demonstration may go hand in hand.


Three clarifications may be considered.

First. Consider the case of a poor couple living in a barrio with ten living children. The husband is unemployed and alcoholic. When he is drunk, he is apt to seek conjugal intercourse regardless of the just desires of his wife and regardless of whether the times are fertile for her. Does the wife commit an evil act if she prepares herself with a contraceptive for the loveless intercourse she foresees?(36) The conjugal act which will take place will be deprived of its power to express love because it will be an act of domination by the husband. If the reasoning of Humanae vitae is followed, the essential wrong of disassociating an act of true love from fertility will not occur, for no act of true love will take place. As Humanae vitae has made clear, the true disorder in a contraceptive act is not “frustration of nature” but disruption of the symbolic nexus of love and fertility.(37) Where there can be no such disruption because no act of love, no symbolic meaning exists and there can be no act contrary to the symbolism. Rather, the wife acts in exercise of her responsibilities as a parent.

To this argument, these objections may be made: (1) The wife wills to be directly sterile which is expressly condemned by the encyclical.(38) (2) The wife does not diminish but does increase the disorder by making a loveless act also an act contrary to the procreative good which must always be respected.(39)

As to (1): the analogy of self-defense is of assistance. It is never lawful to intend directly to take human life or to assert dominion over the life-begetting faculties. The reason is the same. Life and the transmission of life belongs to God. Man does not have unlimited power over life or over the generative powers.(40) But, according to the classic analysis, it is lawful to defend one’s own life by an act which takes the life of the aggressor. In such a case one intends directly to defend oneself and one intends directly the act of self-defense; that the same act is life-taking is an evil consequence accepted as outweighed by the good effect—the evil is only indirectly intended, no direct dominion over another’s life is asserted.(41) A pari, when the wife defends her procreative responsibility here, she intends directly to exercise responsible judgment; that the same act is sterilizing is an evil consequence outweighed by the good effect—the evil is only indirectly intended, no direct dominion over the generative facilities as such is asserted.

Further, it may be said that a sterilizing intention is wrong because it asserts human dominion over what God has reserved as sacred, the nexus of fertility and conjugal love. But when the act of the husband will foreseeably destroy this nexus, the intent of the wife is not to destroy the nexus but to diminish the disorder. No sacred nexus exists. The indissoluble bond which God has willed that man not break on his own initiative is, Humanae vitae teaches, “between the meaning of unity and the meaning of procreation.”(42) It is not a bond between two things, but between two meanings. If one meaning does not exist, as by hypothesis it will not, no natural bond can exist to be destroyed.

As to (2): there is indeed disorder which gives rise to the wife’s choice. But in choosing not to conceive a child irresponsibly, she does not increase the disorder. Through no fault of hers the symbolic nexus does not exist. She acts to reduce the evil. She does not act “against life,” but to protect her parental responsibilities.

Second. Consider the case of spouses who have five children; the wife’s health will be endangered by a pregnancy; the husband travels frequently; there will be a number of months in which they will not be together at an unfecund time. Jointly they decide they should have no more children for the present. Jointly they decide that their marital unity is endangered by prolonged conjugal continence. Jointly they determine to use contraceptive intercourse on certain occasions. Do they necessarily engage in conduct condemned by the encyclical?

This case corresponds by design to the general situation, described by the French episcopate in its response to Humanae vitae, of a choice between alternative duties, “une alternative de devoirs.” If the couple faces alternative duties, the French bishops said, they must decide “which duty is the greater.”(43) The consciences of the couple are left to make the choice. If they choose conjugal intercourse deprived of fertility, they do not do wrong.

This case is weaker than the first in two respects. The conjugal act will, by hypothesis, express love. Therefore to deprive it of fecundity will attack the sacred symbolic nexus. Further, if this case is good, any conjugal contraception might be justified on the ground that expression of love plus exercise of procreative responsibility usually outweighed the evil consequence of sterility. The prohibition of contraception would be reduced to nothing or almost nothing. Moreover, in buying and placing the disassociative means the couple wills to use these means to achieve a good end. But the encyclical, relying on Christian moral principle as old as St. Paul (Romans 3.8), expressly teaches that such means cannot be justified by a good end.(44)

Nonetheless, Martelet has argued, the case is also ruled by the principle of double effect. Evil means are not chosen in order that good may come. To suppose that in the teeth of the encyclical the French bishops justify such means is to do violence to both their fidelity to the Holy See and their intelligence.(45) Rather a set of physical actions, making one moral whole, are willed with the will to express conjugal love and exercise procreative responsibility; the sterilizing effect is willed indirectly and accepted as an evil consequence outweighed by the good.

The preliminary physical actions of buying and positioning disassociative means are to be regarded as parts of a single moral act, that of conjugal intercourse deprived of procreative power. The encyclical focuses on this whole unit of moral action in condemning the disassociation of procreation and love whether it is accomplished by an act before, during, or after conjugal coitus. It is therefore proper to judge these physical actions as part of a single moral act.

An analogy may assist Martelet’s argument. In defending oneself in a just war, the physical actions of purchasing ammunition and putting it in place are each distinct from the action of shooting a gun in self-defense. If the purchase and positioning of the ammunition were judged as individual moral actions whose purpose was to prepare to kill someone, they would have to be judged evil means. But if they are regarded as parts of a single moral act—just self-defense—they are morally defensible; and so they are commonly judged.(46)

It is never licit to use arms with the direct intention to kill, just as it is never licit to use contraceptives with the direct intention to sterilize. The arms will violate the human person by killing just as the contraceptives will violate the human person by destroying the structure of the sexual act. As intended for use against the person, neither weapons nor contraceptives are indifferent. But the intention of self-defense legitimates the use of arms and the intention to exercise procreative responsibility legitimates the use of the contraceptive.

A defender of Martelet and the French bishops could add that the analysis applies only in circumstances where the exercise of procreative responsibility and expression of conjugal love cannot otherwise be accomplished— in short, in circumstances which, if not rare, would not be common. Only in such circumstances would the good accomplished be great enough to outweigh the evil of disassociating fertility from the expression of love. Moreover, the good accomplished, as the French bishops make clear, could never outweigh the right to life of already existing life. As far as conformity with the encyclical goes, the position of the French bishops was reached with much deliberation.(47) It was anticipated by the bishops of Belgium and echoed by the bishops of Canada.(48) It was not repudiated by Paul VI. He had made no attempt in Humanae vitae to decide “concrete cases.”(49) That concrete cases should be relatively plentiful in which the prohibition of Humanae vitae would not be effective would be no defect in the encyclical and no objection to this particular instance of the principle of double effect.

The authority supporting this conclusion, and its non-repudiation by the Holy See, must make anyone hesitate to criticize it.50 But the couple does will to use means disassociating love and fertility. Their will to use such means is inescapably, necessarily, part of their will in these circumstances to “exercise procreative responsibility.” Unlike the first case where, by hypothesis, no union of the expression of love and of procreative power would have existed, here an actual union of the two meanings would occur but for the use of means preventing the union. The use of disassociative methods is an intervention in the signification of the sexual act. Is not the person violated when the signification of the act is violated?(51)

Further, the Council explicitly teaches that governing the use of methods are “objective criteria taken from the nature of the person and his acts.”(52) But here the appraisal of the proportionate good justifying the resort to disassociative methods as a last resort is a subjective, or at the least, a highly circumstantial judgment. Are the criteria employed taken from the nature of the person?

Answering the first of these questions affirmatively, and the second negatively, I would turn to a third case which does not appear to be open to these objections.

Third. Nature implies normality. The teaching of the Church builds on the natural rhythm of fertility and sterility. There is, consequently, as Martelet puts it, “the fundamental right to the regularisation of the cycle.”53 If the rhythm is irregular, it is not natural. Means may be taken to correct it.(54) When a spouse uses such means, there again may be a double effect—the achievement of a regular rhythm, the sterilizing of intercourse. As the good effect achieved is the very basis of the teaching—that is, the natural rhythm—the good outweighs the indirect evil consequences.

Such an analysis makes comprehensible how Martelet can observe, “At all cost, then, we must distinguish between contraception and contracep¬tion.”(55) Only one kind of contraception is condemned by Humanae vitae: “There is really contraception when one deprives the speech of love of a power of life which it normally would have at the time.”(56) The italics are Martelet’s. The disassociation of the normal unity of procreative power with the conjugal act is the offense against the divine plan which Paul VI repudiates.

In elaboration of the distinction between contraception and contraception, Martelet offers the analogy of digitalis. Digitalis is a poison, which can kill. Used therapeutically, it can sustain life.(57) The analogy may be accepted and carried further. When digitalis is used therapeutically we do not speak of it as a poison but as a medicine. It would be confusing to speak of it in both contexts as a poison. Similarly it is confusing to speak of contraception and contraception. As the encyclical does not use the term, it would be good to avoid it and to speak, on the one hand, of condemned methods of depriving the unitive act of procreative power and, on the other hand, of lawful means employed to assure the natural regularity of the rhythm of fertility and sterility. The condemned means are disassociative or disruptive, the permitted means are regulative. For accuracy we must say not “contraceptive,” but “disassociative means”; not “contraception,” but “disruption of the unity.”

In the light of this distinction, the achievement of the natural rhythm of sterility may be accomplished by therapeutic agents which affect the hormones and are indirectly sterilizing or by other means which assure sterility at the times nature intends sterility. In each case the good intended and achieved is not mere menstrual regularity but the actual rhythm of fertile and sterile periods which God has designed for human beings. If God intends the human sexual act to be fruitful, He does not intend it to be fruitful thirty days a month. The bond between the expression of love and the power to procreate is absolute when it occurs, but rhythmic in its occurrence. The rhythm is such that there is a peak phase of fertility when a follicle has ripened (“ovulation”) and phases where the possibility of conception is very low. Like all natural events, probabilities determine the likelihood of conception occurring or not. In the peak phase, if intercourse takes place, the fertilization of an egg by sperm is not certain, but fairly probable (15-25%). In the low phases, fertilization is improbable (1% or 2%).(58) Determining the normal by what is probable we may say that it is normal to conceive during the peak phase and abnormal to conceive during the low phases. This rhythm of probable fertility followed by probable sterility is what God has inscribed in our natures. We may seek to assure it by hormonal regulation. May we not assure it by other means? In using them we intend to achieve the good of this normal rhythm. Such means may of course be employed only at such times in the cycle in which fertility is not normally intended by nature. The regulative effect then intended will not be the disruption of the union of natural procreative power and the conjugal act, but the restoration of the rhythm of fertility-sterility, which is the divine plan for mankind. In eliminating improbable or abnormal fertility, use of such means would eliminate a “true anomaly.”(59)

In considering when fertility is intended by nature, what is specifically human in reproduction must be considered. Unlike mammals such as the rat, a woman is not fertile at all times but only on a periodic basis. Unlike coitus in mammals such as the cat, human coitus does not normally trigger ovulation, so that there is in human beings no intrinsic relation between the coital act and fertilization.(60) Unlike any animal, there is no connection in human beings between copulation and the time of ovulation.(61)

Moreover, unlike the sperm of birds and reptiles, the spermatozoa of men is short-lived. A turtle’s sperm may last naturally for four years; an African night adder’s for five months; a copperhead’s for eleven days.(62) Human sperm are estimated to live no longer than forty-eight hours as a normal maximum; seventy-two hours is an outer limit.(63) For all female mammals, ova are among the most shortlived cells in the body. But a ferret’s ova will last as long as twenty-four hours. The best estimate of the normal life of a woman’s egg is under twenty-four hours. Hence, the human period of fertility is uniquely brief.

Since the sperm may live forty-eight hours, intercourse on the day of ovulation or two or three days before ovulation will normally be fertile. At all other times, intercourse will be normally infertile. At the most on four days a month is the union of intercourse and fertility normal.(64) If we seek to understand the divine plan from what nature has given humanity, we must infer that it is for a brief part of any life that fertility is intended, and that nature has designed man so that many acts of intercourse will be sterile. If sterility is secured at all times save the fertile time intended by nature, the natural design is secured.

The following objections will occur: (1) The encyclical says that “every act whatsoever” which intends to impede procreation must be rejected.(65) But this analysis accepts acts which intend to impede procreation. (2) The encyclical repeats earlier condemnations of the Church of any direct sterilizing of men or women, permanently or for a period. But this analysis permits sterilizing for a period.(66) (3) The encyclical rejects the control of births by “artifice.” But this analysis accepts the use of artificial means.(67) (4) If the proposed means are used, either sterility is assured which is already present, which is a vain thing, or sterility is introduced which disassociates love and fertility. Therefore the analysis permits either an unnecessary action or an evil one. (5) The encyclical warns against the grave consequential dangers in the acceptance of artificial means—the increase of conjugal infidelity; the encouragement of sexual promiscuity among the young; disrespect for women treated as objects of male lust; abuses by public authorities forcing contraceptive practices upon their countries.(68) But this analysis leaves the door open to such results. (6) This analysis treats the body as an objective nature distinct from the person. But the acting person is a unity.(69) We cannot separate body and person and prescribe what is natural by looking at bodily rhythms alone. (7) We cannot know precisely and directly when ovulation is occurring. We have knowledge only by signs—changes in the cervical mucus so that it becomes wet, stretchy, and lubricative, and increase in basal body temperature.(70) These signs indicate that intercourse may be fertile because ovulation is about to occur, is occurring, or has just occurred. A couple cannot determine more precisely when ovulation occurs. The limit on the couple’s knowledge means that the couple must go by signs rather than by reality. The couple should treat the entire period of the signs of fertility as the actual fertile period intended by nature; and that period will be more than four days.(71) Finally: the encyclical was the work of years of study and of great public importance. But this minimizing analysis reduces its scope to four days a cycle and trivializes the great truth the encyclical conveys.

In response, it may be said:

First. The encyclical does not speak literally when it says “every act whatsoever,” because the encyclical a little later specifically permits therapeutic measures which have an indirect contraceptive effect.(72) Further, the condemnation is no broader than the reason for the condemnation. The reason for the condemnation is the natural association, established by God, between conjugal intercourse and procreation. What is condemned is the breaking of this natural nexus.(73) But an unnatural nexus is broken when measures are used to assure sterility outside of the normal ninety-six hours of fertility. Further, the encyclical says that “every conjugal act whatsoever must be intrinsically (per se) open to the transmission of life,”(74) and again, despite its italics and the comprehensive “whatsoever,” it does not speak literally, because the encyclical has just itself declared, “In fact, as is known by usage, new life does not arise from every conjugal coupling. For God has so wisely disposed natural laws and the times of fecundity that they themselves intrinsically (per se) put intervals between acts of generation.”(75) According to the encyclical then, there are times which are intrinsically sterile, but every conjugal act must be intrinsically open to transmitting life. Is a conjugal act at a time which is intrinsically sterile intrinsically open? Not in any literal sense. Are the conjugal acts of spouses whose sterility has been established, or the conjugal acts of a pregnant spouse, intrinsically open to the transmission of life? Literally, no. They are closed from transmitting life by physical causes. Yet they are entirely lawful. It is clear then that, concretely, not every act need to be open to the transmission of life; and it is inferable that to preserve the sterility of times which are intrinsically sterile is unobjectionable. To secure such sterility is not to act against the divine design but to cooperate with it.

Suppose that a wife who was pregnant chose for reasons of health or comfort to employ a contraceptive in conjugal intercourse: would such intercourse be intrinsically less open to the transmission of life than it already was? Obviously not. The same holds true if a contraceptive were employed by an elderly person past the age of childbearing. Is it any different if a contraceptive is used on, say, the first day following the end of menstruation, when conception is improbable? In each of these cases, the conjugal act in the concrete cannot transmit life, and use of a contra¬ceptive in no way increases this inability to transmit life.

When sterility is secured, respect is retained for the special language in which the expression of love and the power to procreate life are joined. The symbolic meaning of the nexus is maintained. But this meaning is channelled and confined to the period in which nature has intended that the association of love and fertility occur. The notion of nature “becomes liberating.”(76) Building on the natural laws of our being, the assurance of sterility at its normal time denies no symbol but sharpens and clarifies the union which does exist for a short period each month between love and procreative power.

Second. The encyclical does reiterate earlier condemnations of any direct sterilization even for a period. But this condemnation must be read in conjunction with the encyclical’s acceptance of a natural rhythm of fertility and sterility. The reason a sterilizing act is wrong is that it asserts man’s dominion over the generative process and effects the disruption of the natural nexus. But when steps are taken to assure that intercourse is not fertile in a period not intended by nature to be fertile, man acts in subordination to the divine plan and does not effect any disruption of the sacred link between love and fertility. Further, the directly intended act is the assurance of natural sterility. Applying the principle of double effect, the good effect intended outweighs the sterilizing effect, even if it were conceded, for purposes of argument, that this effect was in this context evil.

Third. The encyclical does use the term “artifice” to refer to certain contraceptive means, but it does not rest its condemnation on the artificial character of contraceptives, nor does it rest its condemnation on the fact that contraception involves human intervention in a natural process. The encyclical indeed insists that humans are to obey the laws inscribed in their being “with prudence and love.”(77) The Council had already taught that the objective criteria must be taken not just from “the act” of intercourse, as in the older analysis, but from “the person and his acts”—the Council had already put the criteria on the level of the encounter of persons in love.

As Martelet observes, the temperature method of regulating conception is not any more “natural” and not any less of a human intervention to produce sterile intercourse than other methods.78 All methods of having intercourse without conception depend on human intelligence and are “artificial.” What the encyclical condemns is not the artificial nor the intelligent nor the prudent and the human, but the deliberately willed disassociation between the conjugal act and the natural rhythm of fertility. No such disassociation is intended here.

Fourth. The act defended is neither vain nor evil. It supposes that the most prudent estimate will be made of when ovulation occurs. For seventy- two hours before and twenty-four hours thereafter no disassociation is attempted between fertility and conjugal intercourse. Otherwise, means are employed to regulate the rhythm and assure sterility. These means are not vain because there can be irregularity or uncertainty as to the exact time of ovulation. Are human beings more in conformity with the divine plan if they submit to the blind chance of this irregularity or uncertainty? God forbid. As Paul VI teaches, God has instituted marriage itself so that it not be the sport of “the blind course of natural forces” but exhibit God’s “plan of love.”(79) It dishonors the divine plan to say that the expression of human joined to procreative power must be the result of blind chance. Its high symbolic significance as an imitation of the loving activity of God depends on its accomplishment with loving intelligence.

Fifth. The consequential dangers of contraception outlined by the encyclical are present in the acceptance of any method of regulating fertility including the use of the temperature method of securing sterility. But just as use of the temperature method at least instills a measure of restraint in sexual conduct, so acceptance of the encyclical as just expounded instills a measure of restraint: for, as expounded, Humanae vitae sets limits. It is unlawful to have intercourse and employ methods which destroy fertility in the naturally fertile period. In this period continence must be observed if there are reasons for not desiring a child. There is thus still, in such circumstances, a need to rhyme conjugal continence with conjugal intercourse.(80) The period in which nature itself intends fertility may not be invaded. Short though this period is, it must be respected, and conjugal intercourse, if it is undertaken, must be undertaken in conformity with the divine plan for the transmission of life.

Sixth. This analysis does not separate body from person. It looks at a component of every heterosexual act, the existence of a fertile or sterile condition. It proceeds from the commonplace observation that those conditions are cyclical. It avails itself of the scientific discoveries that teach that, unlike the fertility of brute beasts, human fertility is fleeting, is not induced by coitus, and does not induce coitus. In man the choice of a time for sexual intercourse is a human choice. Because it is, intercourse has the meaning of expressing love and the meaning of expressing procreative power. But at those times when nature intends no procreation, there is no interference in the structure or signification of the sexual act when means are used increasing the probability that the natural rhythm will hold. The whole person is involved in the choice of a fertile or infertile time of intercourse and in the choice of means to increase the chances of infertility at the time of normal infertility.

Seventh. When it is said that a couple should go by the signs of fertility rather than by the fact of fertility, the crux is reached. There is a peak phase when fertility is probable and low phases when it is improbable. These probabilities are fundamental. There are further contingencies: there may be a second ovulation within a single period. There may be unusually long- lived sperm. Because of the range of the fundamental possibilities and because of the unusual contingencies, the proponents of various forms of natural family planning have counselled abstinence for durations substantially greater than the necessary if only the normal components are kept in mind.(81) But the requirements of successful natural family planning must not be confused with the requirements of divine law. If for divine law the norm is decisive, only one ovulation per period need be considered, and only ova and sperm of normal life need be supposed. For the purpose of applying divine law, the norm of fertility need not be greater than four days.(82)

But which four days? the objector presses. The four days are to be selected by the most prudent means available to any given couple. The most prudent means will vary with the couple and will depend on such factors as the luteal cycle of the particular woman. Cervical mucus, temperature change, experience of menstrual regularity can also be used to make the prudent estimate.

To recapitulate, an adequate answer to the seventh objection depends on a firm grasp of the principle that probability establishes what is normal; of the principle that respect for the normal does not require allowance for the abnormal but calls rather for its reduction; and of the principle that in applying any rule prudence in the estimate of probabilities is all that human beings are required to use.

Finally. When it is said that this interpretation of Humanae vitae is minimizing and reduces its impact to a small portion of a couple’s married life, it must be answered that it is scarcely an objection that the scope of a law should be narrow. In general, Christians have been called to liberty. Here, in respect to a pattern built into our biological nature by which we cooperate with God, we are asked to observe the unbreakable normal nexus of fertility and love. The teaching is surely not of a quantitative character. Do we worship God less because we are called to worship him formally only one day in seven?


1 See Second Vatican Council, Gaudium et spes, Pastoral Constitution on the Church in the Modern World, Concilii Oecumenici Vaticani II Constitutiones, Decreta, Declarationes, ed. Florentio Romita (Rome, 1967) sec. 51, n. 14. For references to the Council, see Paul VI, Humanae vitae, Acta apostolicae sedis 60, 481 (1968) sec. 9, n. 8; sec. 10, n. 10; sec. 24, n.28 and n. 30; sec. 25, n. 32; sec. 26, n. 38.

2 Philippe Delhaye, “L’Encyclique Humanae Vitae et l’enseignement de Vatican II sur le mariage et la famille (Gaudium et spes),” Bijdragen tijdschrift voor philosophie en theologie 29 (1968), pp. 351-367.

3 Karol Wojtyla, Fruitful and Responsible Love (New York: The Seabury Press, 1979), p. 16.

4 Cf. Gustave Martelet, S.J., “Pour mieux comprendre l encyclique ‘Humanae vitae ,” Nouvelle revue theologique 90 (1968), p. 1014: “Tel est le principe de continuity profond entre lencyclique et le Concile quil doit commander toute interpretation veritable d‘HUMANAE VITAE. Non seulement encyclique et Concile ne se contredisent pas, mais ils s’eclairent reciproquement. ”

Father Martelet has been credited with a part in the preparation of the encyclical itself: see John Horgan, editor, Humanae Vitae and the Bishops (Shannon: Irish University Press, 1.972) p. 13. It would be inexact to identify the views expressed in his article with the encyclical, but they may be taken to represent the thoughts of one familiar with the thoughts of Paul VI and anxious to do justice to them.

5 Wojtyla, Fruitful and Responsible Love, p. 20.

6 Gaudium et spes, sec. 49: “Ille autem amor, iitpote eminenter humanus, cum a persona in personam voluntatis affectu dirigatur, totius personae bonum complectitur ideoque corporis animique expressiones peculiari dignitate ditare easque tamquam elementa ac signa specialia coniugalis amicitiae nobilitare valet.”

7 Humanae vitae, sec. 10: “quoniam humana ratio in facultate vitae procreandae biologicas deprehendit leges, quae ad humanam personam pertinent.”

8 Ibid., sec. 9: “de peculiari ilia personalis amicitiae forma.”

9 Ibid.,, sec. 8: “Iamvero coniugalis amor turn nobis maxime veram suam naturam nobilitat- emque ostendet, si ilium, quasi a supremo quodam fonte, a Deo manare cogitaveriumus, qui CARITAS EST, (1 John 4.8), quique Pater est, EX QUO OMNIS PATERNITAS IN CAELIS ET IN TERRA NOMINATUR (Eph. 3.15).”

10 See pp. 238-246 above.

11 Martelet, “Pour mieux comprendre l’encyclique,” p. 906.

12 Gaudium et spes, sec. 49. “Haec dilectio proprie matrimonii opere singulariter exprimitur et perjicitur”

13 Humanae vitae, sec. 11: “cum non cesset eorum destinatio ad coniugum coniunctionem signijicandam roborandamque.”

14 Ibid., sec. 14: . . . usum matrimonii alteri coniugi impositum, nulla ratione habita eius status eiusque iustorum optatorum, non esse verum actum amoris, atque adeo Us adversari rebus, quas circa necessitudiness inter coniuges moralis recte postulat ordo”

15 See pp. 491-492 above.

16 Gaudium et spes, sec. 50: “Hoc iudicum ipsi ultimatim coniuges coram Deoferre debent."

17 Humanae vitae, sec. 10: “Si postea ad condiciones physicas, oeconomicas, psychologicas et sociales respicimus, it paternitate conscia fungi dicendi sunt, qui aut, prudenti consideratione magnoque animo ducti, statuunt numerosiores suscipere libqros, aut, seriis causis moralibusque praeceptis observatis, animum inducunt ut, vel ad certum vel ad incertum tempus, alium filium non gignant.”

18 Martelet, “Pour raieux comprendre,” p. 1036: “I’unite qui regne dans I’union conjugate entre expression d’amour et pouvoir de transmettre la vie napparait plus seulement comme un symbole de la tache du monde, elle apparait aussi comme symbole du Dieu vivant lui- mSme.”

19 See pp. 279-281 above.

20 Gaudium et spes, sec. 51: “Moralis igitur indoles rationis agendi, ubi de componendo amore coniugali cum responsabili vitae transmissione agitur, non a sola sincera intentione et aestimatione motivorum pendet, sed obiectivis criteriis, ex personae eiusdemque actuum natura desumptis, detenninari debet, quae integrum sensum mutuae donationis ac humanae procrea- tionis in contextu veri amoris observant.”

21 Humanae vitae, sec. 14: “Item quivis respuendus est actus qui, cum coniugale commercium vel praevidetur vel efficitur vel ad sues naturales exitus ducit, id tamquam finen obtinendum aut mediam adhibendam intendat, ut procreatio impediatur.”

22 Ibid., sec. 12: “Huiusmodi doctrina, quae ab Ecclesiae Magisterio saepe exposita est, in nexu indissolubili nititur, a Deo statuto, quem homini sua sponte infringere non licet, inter significationeni unitatis et significationem procreationis, quae ambae in actu coniugali insunt."

23 See pp. 44-45 above.

24 Pius XI, Casti connubii, Acta apostolicae sedis 22.560 (1930).

25 Humanae vitae, sec. 12: “Putamus nostrae aetatis homines aptissimos esse ad perspicien- dum, quam haec doctrina sit humanae rationi consentanea."

26 Cf. Robert E. Rodes Jr., “A Prospectus for a Symbolist Jurisprudence,” Natural Law Forum, pp. 88, 107 (1957): “. . . the meaning of sex is God’s love incarnate, incarnate first in nature, and later in His son ... it follows that the particular use of sex should be so undertaken as to be symbolic of this incarnate love.”

27 Humanae vitae, sec. 13: “is non quidem dominum se confitetur fontium vitae, sed potius ministrum consilii a Creatore initi.”

28 See p. 529 above.

29 Humanae vitae, sec. 16: “. . . Ecclesia docet, tunc licere coniugibus sequi vices naturales, generandi facultatibus immanentes, in maritali commercio habendo iis dumtaxat temporibus, quae conceptione vacent ...”

30 Ibid., sec. 16: “lidem sane, haec agentes, vere et omnino recti amoris testimonium prae- bent. ”

31 Casti connubii at 561; Pius XII, "Allocutio iis quae interfuerunt Conventui Societatis Catholicae Italicae inter Obstetrices,” Acta apostolicae sedis 43, 846 (1951); also Acta aposto- licae sedis 43, 859.

32 Humanae vitae, sec. 16: “. . . coniuges legitime facultate utuntur, sibi a natura data. ”

33 Ibid., sec. 15: “Ecclesia autem illas medendi rationes haud illicitas, quae ad morbos corporis curandos necessariae sunt, etiamsi exiunde oriatur procreationis impedimentum, licet praevisium, dummodo ne hoc impedimentum ob quamlibet rationem directo intendatur."

34. Pius XII, "Allocutio ad VII Conventum Societatis inter omnes gentes de Haematologia,” Acta apostolicae sedis 50, 734-735 (1958).

35 Humanae vitae, sec. 24: "Ita quidem docti homines, it praesertim que catholici nomine censentur, sua data opera res plane se habere, ut Ecclesia docet, nempe ‘veram contradictionem inter divinas leges vitae transmittendae et germani amoris coniugalis fovendi adesse non posse,’ GAUDIUM ET SPES, SEC. 51.”

36 Cf. Paul Chauchard, Amour et contraception (Paris: Maison Marne, 1965), pp. 108-109; M. Zalba, Rassegna di Teologia 9 (1968), p. 234, cited and agreed with by Bertrand de Margarie, “Reflections on Some Aspects of Humanae Vitae to Which Less Consideration Has Been Given,” Osservatore Romano, May 25, 1978.

37 Martelet, “Pour mieux comprendre,” p. 1029: “[V ency clique] fond la loi quelle dit ‘natu- relle’ sur un lien inviolable de SIGNIFICATION.”

38 I bid., sec. 14: “Pariter, sicut Ecclesiae Magisterium pluries docuit, damnandum est sen viros seu mulieres directo sterilitate, vel perpetuo vel ad tempus, afficere.”

39 Cf. The Bishops of the United States, “Human Life in Our Day,” Joint Pastoral Letter of November 15, 1968, reprinted, Horgan, ed. Humanae Vitae and the Bishops, p. 270: “There are certain values which may not oblige always to act on their behalf, but we are prohibited from ever acting directly againjst them by positive acts. Truth is such a value; life is surely another.”

40 Humanae vitae, sec. 13: “Sicut enim homo, in universum, corporis sui non hahet infinitam potestatem, ita etiam, et sane peculiari ratione, no genitalium quidem virium qua talium, quoniam hae suapte natura ad vitam humanam progigendam spectant, cuius Deus principium est. ”

41 Thomas Aquinas, Summa theologica 2-2, Q.64, art. 7, corpus: “Respondeo dicendum quod nihil prohibet unius actus esse duos effectus, quorum alter solum sit in intentione, alius vero sit praeter intentionem. . . Ex actu ergo alicuius seipsum (jefendentis duplex effectus sequi potest; unus quidem conservatio propriae vitae; alius autem occisio invadentis. Actus ergo huiusmodi, ex hoc quod intenditur conservatio propriae vitae, non habet rationem illiciti. . . Potest tamen aliquis actus ex bona intentione proveniens illicitus reddi si non sit proportionatus fini. ”

42 Humanae vitae, sec. 12: “. . . nexu indissolubili . . . inter significationem unitatis et significationem procreationis . . . Cf. Martelet, “Pour mieux comprendre,” p. 1028: “Notons- le bien surtout: ‘Ce lien indissoluble que Dieu a voulu et que I’homme ne peut rompre de son initiative,’ nest pas pour Vencyclique un lien entre deux CHOSES, mais ‘entre les deux SIGNI¬FICATIONS de Pact conjugal, que sont I’union d’amour et la fecondite de vie.’”

43 The Bishops of France, “Pastoral Note, November 9, 1968, sec. 16,” Informations catholiques internationales, November 15, 1968.

44 Humanae vitae, sec. 14: “numquam tamern licet no ob gravissimas quidem causas, facere mala ut eveniant bona”

45 Cf. Martelet, “Pour mieux comprendre,” pp. 1055-1056.

46 Cf. Albertus Magnus, Commentaria in Sententiarum Libros P. Lombardi 4, 16 sol., Opera omnia 29, 637; see Frederick H. Russell, The Just War in the Middle Ages (Cambridge: Cambridge University Press, 1975), pp. 276-277.

47 See Horgan, Humanae Vitae and the Bishops, pp. 12-14.

48 The Bishops of Belgium, August 30, 1968 in Horgan, p. 66; and the Bishops of Canada, September 27, in Horgan, p. 81.

49 Martelet, “Pour mieux comprendre,” p. 1015: “[Paul VI] rappelle la nomne que Von risquait de voir flechir, il ne precise pas les conditions qui vont permettre de s’y plier. II ne les nie pas non plus. 11 les suppose

50 The insistence of John Paul II on acceptance of “the exigent but uplifting teaching” of Humanae vitae (e.g., his allocution to a group of Bishops of Indonesia on their ad limina visit, June 7, 1980, Osservatore Romano June 9, 1980) should not be construed as a tacit repudiation of the gloss of the French and other hierarchies when their teaching is not mentioned and when their teaching professes to be in harmony with the encyclical.

51 Cf. “Les fondaments de la Doctrine de l’Eglise concernant les principes de la vie conju- gale,” a memoir prepared by a group of moral theologians of Cracow with the active participation of Cardinal Wojtyla, Analecta Cracoviensia 1, 193 (1969), at p. 202: “L’emploi des contraceptifs constitute une intervention dans la structure de I’acte sexuel, et done de lagir de personne, etant ainsi la violation de personne . . . ll ne s’agit, done, pas ici de l emploi d’un moyen en soi indifferent (comme Vest, par example, une arme), dont on peut se servir de fagon bonne ou mauvaise en dependance de Vintention de sujet agissant."

52 Gaudium et spes, sec. 51.

53 Martelet, “Pour mieux comprendre,” p. 1046: “le droit fondamental d la regularisation du cycle."

54 Ibid., p. 1047: "Chercher a retahlier un reel equilibre de sort que I'expression damour n’ait pas dautre fecondite que celle qui releve de la normality d’un cycle nest pas faire de la contraception." See also the theologians’ discussion before the encyclical reported 011 pp. 462- 464 above. It is one thing “intervenir dans les lois biologiques de la personne," Memoir of the Cracow moral theologians at 202, in the sense of contravening these laws. It is quite different to intervene to correct and regularize them, as happens daily in the practice of medicine.

55 Martelet, “Pour mieux comprendre,” p.. 1047 n. 68: “11 faut done distinguer d tout prix entre contraception et contraception.”

56 Ibid., “II y a reelement contraception lorsque I’on price de son pouvoir de vie un language d’amour que NORMALEMENT I’aurait ALORS.”

57 Ibid., p. 1047, n. 68.

58 Rodrigo Guerrero, "The Aging of Gametes,” Linacre Quarterly

59 Martelet, “Pour mieux comprendre,’' p. 1046: “. . . I’unite de I’amour et de la vie qui est en principe une unite rhythmee peut devenir une reelle anomalie, lorsqu’elle est donne dehors de tout rhythme.”

60 For the rat, see S. A. Asdell, Patterns of Mammalian Reproduction (Ithaca: Cornell University Press, 1964), p. 325. For the cat, see H. P. Cole and P. T. Cupps, ed., Reproduction in Domestic Animals (New York and London: The Academic Press, 1969), p. 359. Cf. Chaucard, Amour et contraception, p. 136.

61 Michael J. K. Harper and M. C. Chang, “Some Aspects of the Biology of Mammalian Eggs and Spermatozoa,” in Marcus W. H. Bishop, ed., Advances in Reproductive Physiology, pp. 5, 170.

62 A. D. Johnson and C. W. Foley, eds., The Oviduct and its Functions (New York and London: The Academic Press, 1974), pp. 24a, 204.

63 Carl Hartman, Science and the Safe Period (Baltimore: The Williams and Wilkins Co., 1962), p. 74.

64 E. S. E. Hafez and R. J. Blandau, eds., The Mammalian Oviduct: Comparative Biology and Methodology (Chicago and London: University of Chicago Press, 1969), pp. 139, 141.

65 Humanae vitae, sec. 14: “quivis . . . actus.”

66 Ibid., sec. 14.

67 Ibid., sec. 7: “artificiosas vias” and sec. 17: “ad natorum incrementa artificio coercenda adhibitus.”

68 Ibid., sec. 17.

69 Cf. the Cracow theologians, Analecta Cracovensia (1969), pp. 1, 202.

70 Mary Shivanandan, Natural Sex (New York: Warson, Wade, 1979), pp. 44-50.

71 Ibid., p. 52.

72 Humanae vitae, sec. 15.

73 Ibid., sec. IZ.

74 Ibid., sec. 11; “. . . quilibet matrimonii usus ad vitam humanam procreandam per se destinatus permaneat.” (Italics in original.)

75 Ibid., sec. 11: “revera, ut usu noscitur, non ex unaquaque coniugali congressione nova exoritur vita. Deus enim naturales leges ac tempora fecunditatis ita sapienter disposuit, ut eadem iam per se ipsa generationes subsequentes intervallent. ”

76 Martelet, “Pour mieux comprendre,” p. 1047: “La notion de NATURE que parait tout d'abord a certains inhumaine, est en reality liberatrice.”

77 Humanae vitae, sec. 31: “. . . leges . . . quae sunt prudenter amanterque colendae.”

78 Martelet, “Pour mieux comprendre,” p. 1048: “Le caractere NATUREL, c’est-a-dire con- forme a la veriti de I’amour, de la continence periodique ne consiste done pas dans I’absence d’artifices—puisque toute methode est par nature artificielle—elle ne consiste pas davantage dans le fait qu’elle pourrait indiquer le meilleur moment des recontres; elle consiste seulement en ceci qu’elle PERMET a un couple de respecter lorsqu’il est rhythmiquement donne, le rapport des expressions de son amour & son pouvoir possible de la vie.”

79 Humanae vitae, sec. 8: “Tantum igitur abest ut matrimonium e casu quodum vel e caeco naturalium virum cursu nascatur, ut reapsae illud sapienter providenterque Creator Deus ea mente instituerit, ut in hominibus suum amoris consilium efficeret.”

80 Cf. Chauchard, Amour et contraception, p. 143.

81 Shivanandan, p. 53.

82 The conclusion that the signs of fertility may reduce the period in which the use of regulatory means is excluded, but not increase it, differs from the position reached by Andre J. de Bethune, "Assisted (Supplemented) Rhythm—NFP,” Catholic Medical Quarterly 30 (1979), pp. 67-77; “Discussion and Replies,” ibid, 30 (1979), pp. 157-160, 195-197; 31 (1980), p. 47. Bethune appears to treat the signs of fertility as decisive. I am indebted to both Professor Bethune and Professor Josef Fuchs, S.J. for their comments on a draft of this article.