1. We said previously that the principle of conjugal morality, taught by the Church (Second Vatican Council, Paul VI), is the criterion of faithfulness to the divine plan.
In conformity with this principle the Encyclical "Humanae vitae" clearly distinguishes between a morally illicit method of birth regulation or, more precisely, of the regulation of fertility, and one that is morally correct.
In the first place "the direct interruption of the generative process already begun ('abortion') is morally wrong" (HV 14), likewise "direct sterilization" and "any action, which either before, at the moment of, or after sexual intercourse, is specifically intended to prevent procreation" (HV 14)--therefore, all contraceptive means. It is however morally lawful to have "recourse to the infertile periods" (HV 16): "If therefore there are reasonable grounds for spacing births, arising from the physical or psychological conditions of husband or wife, or from external circumstances, the Church teaches that then married people may take advantage of the natural cycles immanent in the reproduction system and use their marriage at precisely those times that are infertile, and in this way control birth without offending moral principles..." (HV 16).
2. The encyclical emphasizes particularly that "between the two cases there is an essential difference" (HV 16), and therefore a difference of an ethical nature: "in the first case married couples rightly use a facility provided them by nature; in the other case, they obstruct the natural development of the generative process" (HV 16).
From this there derive two actions that are ethically different, indeed, even opposed: the natural regulation of fertility is morally correct; contraception is not morally correct. This essential difference between the two actions (modes of acting) concerns their intrinsic ethical character even though my Predecessor Paul VI states that "in each case married couples, for acceptable reasons, are both perfectly clear in their intention to avoid children," and he even writes: "that they mean to make sure that none will be born" (HV 16). In these words the document admits that even those who make use of contraceptive practices can be motivated by "acceptable reasons"; however, this does not change the moral character which is based on the very structure of the conjugal act as such.
3. It might be observed at this point that married couples who have recourse to the natural regulation of fertility, might do so without the valid reasons spoken of above. This, however, is a separate ethical problem, when one treats of the moral sense of "responsible parenthood."
Supposing that the reasons for deciding not to procreate are morally correct, there remains the moral problem of the manner of acting in this case, and this is expressed in an act which--according to the doctrine of the Church contained in the encyclical--possesses its own intrinsic moral qualification, either positive or negative. The first one, positive, corresponds to the "natural" regulation of fertility; the second, negative, corresponds to "artificial contraception."
4. The whole of the previous discussion is summed up in the exposition of the doctrine contained in "Humanae vitae," by pointing out its normative and at the same time its pastoral character. In the normative dimension it is a question of making more precise and clear the moral principles of action; in the pastoral dimension it is a question especially of pointing out the possibility of acting in accordance with these principles ("the possibility of the observance of the divine law," HV 20).
We should dwell on the interpretation of the content of the encyclical. To this end one must view that content, that normative- pastoral ensemble, in the light of the theology of the body as it emerges from the analysis of the biblical texts.
5. The theology of the body is not merely a theory, but rather a specific, evangelical, Christian pedagogy of the body. This derives from the character of the Bible, and especially of the Gospel which, as the message of salvation, reveals man's true good, for the purpose of modeling--according to the measure of this good--mean's earthly life in the perspective of the hope of the future world.
The Encyclical "Humanae vitae," following this line, responds to the question about the true good of man as a person, as male and female, about that which corresponds to the dignity of man and woman when one treats of the important problem of the transmission of life by married couples.
To this we shall devote further reflection.