Ed. and James: Let me rephrase and elaborate:
There are three modes in which infallible doctrinal teaching can be presented by the Magisterium:
1) by the Pope alone,
2) by the Pope and Bishops assembled together in an Ecumenical Council, or
3) by the College of Bishops (including the Pope as its head) even when they are dispersed throughout the world.
The Church's teaching against contraception is a classic example of this third mode of infallibility transmitting the doctrine of Christ.
While you correctly claim, that Humanae Vitae is not in itself an ex cathedra, infallible definition, you incorrectly fail to recognize that the teaching which it contains is infallible and irreformable, by virtue of having been taught constantly and definitively, over a period of many centuries, by a consensus of Popes and Bishops around the world - a consensus which was virtually unanimous until the early 1960s. Any single instance of affirming this doctrine might not in itself be authoritative enough to give us an absolute assurance of its truth; but the cumulative or combined weight of so many affirmations over an extensive period of time does give us that kind of assurance.
Humanae Vitae does not need the supportive corroborative testimony of other papal and episcopal statements in order to assure Catholics that its doctrinal position regarding contraception is immutable and irreformable.
You are inerror, but it is a prevalent error amongst even well-intentioned and orthodox Catholics. It is the idea that in order for a papal pronouncement to be infallible, in terms of Vatican I's conditions, it has to be a dogmatic definition: that is, the highest possible exercise of papal authority. Examples of this from the last century or so would be the dogmatic definitions of Mary's Immaculate Conception and Assumption by Popes Pius IX and Pius XII respectively. In a dogmatic definition we find a particularly solemn form of words (called the modus definitorius in Latin) employed in order to affirm that such-and-such a doctrine concerning faith or morals is revealed by God, and is a part of the Church's deposit of faith. As such, it must be believed with the assent of divine and Catholic faith, and willful doubt or denial of such defined dogma is formal heresy, carrying with it the juridical consequence of excommunication - placing oneself outside the Church.
It simply is not the teaching of either Vatican I or Vatican II that the Church's infallibility (which is enjoyed and exercised by the Pope alone under certain conditions) is limited to the field of dogma, that is, to the determination and promulgation of truths revealed by God in either Scripture or Tradition. Rather, infallibility also covers other truths which are closely linked to divine revelation, and which cannot be denied without endangering this deposit of revealed truth in some way. Examples of these closely related truths would be principles of the natural moral law - many of which are in any case revealed in Scripture as well. The natural law - to which even pagans have access in principle, as St. Paul teaches in Romans 1-2 - is the foundation on which the higher, supernatural law of Christ is based. Hence, the Church has always claimed a divine mandate to guard and interpret the natural law, as Paul VI affirms emphatically in Humanae Vitae.
Paul VI's intention was to hand down a decisive, final judgment on this issue - to settle the controversy once and for all. Or at least, since he foresaw that dissent and protest would in fact continue, his intention was to put an end to any objective grounds for uncertainty or wavering on this issue, on the part of faithful Catholics. JPII's position in Veritatis Splendor was to reaffirm Paul VI.
Papal infallibility is not limited to dogmatic definitions - i.e. judgments as to what is revealed (de fide) and what (in direct contrast) is heretical. Pope Pius IX and the Fathers of Vatican I promulgated the dogma of papal infallibility on the understanding that this prerogative of the Roman Pontiff also included the power to judge questions which are not in themselves matters of revealed truth, but closely related to revealed truth.
Why the papal birth control commission ?
If, after all this, the Pope had been wrong in his decision about contraception, what credibility would be left to the Catholic Church's claim that the Vicar of Christ enjoys a special and unique divine guidance to teach on these matters?
What Paul VI had in mind in referring to "the norms given by Pius XII" was the late Pontiff's final allocution on the subject of contraception, given just a month before his death in 1958. On that occasion Pius XII had expressed disapproval of a particular form of birth regulation which had not existed in the time of Pius XI: the newly-discovered "chemical" means of extending the period of infertility in a woman's cycle - i.e., the contraceptive "Pill." Some theologians who accepted Pius XI's strictures against unnatural methods of birth control were wondering whether perhaps this new intervention might not in fact fall under the ban of Pius XI, insofar as it did not entail - unlike condoms, "withdrawal" or diaphragms - any interference with the physical structure of the conjugal act.
This was the only question which might for a time have been seen by Paul VI as legitimately debatable: not the question of doctrine as to whether unnatural methods of birth control are ever acceptable, but the question of fact as to whether this new chemical invention should be classified as "unnatural" or not.
Get it? Such is the splendor of the truth.
Earnestly,
N.F.
