1. For today we have chosen the theme of "responsible parenthood" in the light of the Constitution "Gaudium et spes" and of the Encyclical "Humanae vitae."
The Council document, in treating of the subject, limits itself to recalling the basic premises; the papal document, however, goes further, giving to these premises a more concrete content.
The Council text reads as follows: "When it is a question of harmonizing married love with the responsible transmission of life, it is not enough to take only the good intention and the evaluation of motives into account; the objective criteria must be used, criteria drawn from the nature of the human person and human action, criteria which respect the total meaning of mutual self-giving and human procreation in the context of true love; all this is possible only if the virtue of married chastity is seriously practiced" (GS 51).
The Council adds: "In questions of birth regulation the sons of the Church, faithful to these principles, are forbidden to use methods disapproved of by the teaching authority of the Church" (GS 51).
2. Before the passage quoted, the Council teaches that married couples "shall fulfill their role with a sense of human and Christian responsibility and the formation of correct judgments through docile respect for God" (GS 50). This involves "common reflection and effort; it also involves a consideration of their own good and the good of their children already born or yet to come, an ability to read the signs of the times and of their own situation on the material and spiritual level, and finally, an estimation of the good of the family, of society and of the Church" (GS 50).
At this point there follow words of particular importance to determine with greater precision the moral character of "responsible parenthood." We read: "It is the married couple themselves who must in the last analysis arrive at these judgments before God" (GS 50).
And it continues: "Married people should realize that in their behavior they may not simply follow their own fancy but must be ruled by conscience--and conscience ought to be conformed to the law of God in the light of the teaching authority of the Church, which is the authentic interpreter of divine law. For the divine law throws light on the meaning of married love, protects it and leads it to truly human fulfillment" (GS 50).
3. The Council document, in limiting itself to recalling the necessary premises for responsible parenthood, has set them out in a completely unambiguous manner, clarifying the constitutive elements of such parenthood, that is, the mature judgment of the personal conscience in relationship to the divine law, authentically interpreted by the Magisterium of the Church.
4. The Encyclical "Humanae vitae", basing itself on the same premises, goes further and offers concrete indications. This is seen, first of all, in the way of defining "responsible parenthood" (HV 10). Paul VI seeks to clarify this concept by considering its various aspects and excluding beforehand its reduction to one of the "partial aspects, as is done by those who speak exclusively of birth control." From the very beginning, indeed, Paul VI is guided in his reasoning by an integral concept of man (cf. HV 7) and of conjugal love (cf. HV 8, 9).
5. One can speak of responsibility in the exercise of the function of parenthood under different aspects. Thus he writes: "In relation to the biological processes involved, responsible parenthood is to be understood as the knowledge and observance of their specific functions. Human intelligence discovers in the faculty of procreating life, the biological laws which involve human personality" (HV 10). If, on the other hand, we examine "the innate drives and emotions of man, responsible parenthood expresses the domination which reason and will must exert over them" (HV 10).
Taking for granted the above-mentioned intra-personal aspects and adding to them the "economic and social conditions," those are considered "to exercise responsible parenthood who prudently and generously decide to have a large family, or who, for serious reasons and with due respect to the moral law, choose to have no more children for the time being or even for an indeterminate period" (HV 10).
From this it follows that the concept of "responsible parenthood" contains the disposition not merely to avoid "a further birth" but also to increase the family in accordance with the criteria of prudence. In this light in which the question of "responsible parenthood" must be examined and decided, there is always of paramount importance "the objective moral order instituted by God, the order of which a right conscience is the true interpreter" (HV 10).
6. The commitment to responsible parenthood requires that husband and wife, "keeping a right order of priorities, recognize their own duties towards God, themselves, their families and human society" (HV 10). One cannot therefore speak of "acting arbitrarily." On the contrary the married couple "must act in conformity with God's creative intention" (HV 10). Beginning with this principle the encyclical bases its reasoning on the "intimate structure of the conjugal act" and on "the inseparable connection of the two significances of the conjugal act" (cf. HV 12), as was already stated previously. The relative principle of conjugal morality is, therefore, fidelity to the divine plan manifested in the "intimate structure of the conjugal act" and in the "inseparable connection of the two significances of the conjugal act."