Profession of Faith
The Catholic Church declared dogmatic facts to be taught infallibly in a June 1998 letter from the Congregation for the Doctrine of the Faith (CDF), which was then headed by Joseph Cardinal Ratzinger, later Pope Benedict XVI:
Such doctrines [are] taught infallibly by the ordinary and universal Magisterium of the Church as a 'sententia definitive tenenda'. Every believer, therefore, is required to give firm and definitive assent to these truths, based on faith in the Holy Spirit's assistance to the Church's Magisterium, and on the Catholic doctrine of the infallibility of the Magisterium in these matters. Whoever denies these truths would be in a position of rejecting a truth of Catholic doctrine and would therefore no longer be in full communion with the Catholic Church.
The CDF explained that dogmatic facts fall under the second paragraph of the Church's Profession of Faith, which states:
'I also firmly accept and hold each and everything definitively proposed by the Church regarding teaching on faith and morals'. The object taught by this formula includes all those teachings belonging to the dogmatic or moral area, which are necessary for faithfully keeping and expounding the deposit of faith, even if they have not been proposed by the Magisterium of the Church as formally revealed.
In discussing "truths connected to revelation by historical necessity and which are to be held definitively, but are not able to be declared as divinely revealed," the letter mentions dogmatic facts in a list of examples: "the legitimacy of the election of the Supreme Pontiff or of the celebration of an ecumenical council, the canonizations of saints (dogmatic facts), [and] the declaration of Pope Leo XIII in the Apostolic Letter Apostolicae Curae on the invalidity of Anglican ordinations."
In his May 1998 motu propio Ad tuendam fidem, Pope John Paul II stated:
This second paragraph of the Profession of faith is of utmost importance since it refers to truths that are necessarily connected to divine revelation. These truths, in the investigation of Catholic doctrine, illustrate the Divine Spirit’s particular inspiration for the Church’s deeper understanding of a truth concerning faith and morals, with which they are connected either for historical reasons or by a logical relationship.[1]
Reasoning
In the 1998 letter, the CDF offered the following explanation for why dogmatic facts fall under the second paragraph of the Profession of Faith:[1]
"The truths belonging to this second paragraph can be of various natures, thus giving different qualities to their relationship with revelation. There are truths which are necessarily connected with revelation by virtue of an historical relationship, while other truths evince a logical connection that expresses a stage in the maturation of understanding of revelation which the Church is called to undertake. The fact that these doctrines may not be proposed as formally revealed, insofar as they add to the data of faith elements that are not revealed or which are not yet expressly recognized as such, in no way diminishes their definitive character, which is required at least by their intrinsic connection with revealed truth. Moreover, it cannot be excluded that at a certain point in dogmatic development, the understanding of the realities and the words of the deposit of faith can progress in the life of the Church, and the Magisterium may proclaim some of these doctrines as also dogmas of divine and catholic faith. ... Such a doctrine can be confirmed or reaffirmed by the Roman Pontiff, even without recourse to a solemn definition, by declaring explicitly that it belongs to the teaching of the ordinary and universal Magisterium ... as a truth of Catholic doctrine (second paragraph). Consequently, when there has not been a judgement on a doctrine in the solemn form of a definition, but this doctrine, belonging to the inheritance of the depositum fidei, is taught by the ordinary and universal Magisterium, which necessarily includes the Pope, such a doctrine is to be understood as having been set forth infallibly. The declaration of confirmation or reaffirmation by the Roman Pontiff in this case is not a new dogmatic definition, but a formal attestation of a truth already possessed and infallibly transmitted by the Church."
Implications
While the Catholic Church distinguishes between truths set forth as divinely revealed (doctrines de fide credenda) or to be held definitively (doctrines de fide tenenda), as dogmatic facts are, the Church has stressed:
"[T]there is no difference with respect to the full and irrevocable character of the assent which is owed to these teachings. The difference concerns the supernatural virtue of faith: in the case of truths of the first paragraph, the assent is based directly on faith in the authority of the word of God (doctrines de fide credenda); in the case of the truths of the second paragraph, the assent is based on faith in the Holy Spirit's assistance to the Magisterium and on the Catholic doctrine of the infallibility of the Magisterium (doctrines de fide tenenda). ... Every believer, therefore, is required to give firm and definitive assent to these truths, based on faith in the Holy Spirit's assistance to the Church's Magisterium, and on the Catholic doctrine of the infallibility of the Magisterium in these matters. Whoever denies these truths would be in a position of rejecting a truth of Catholic doctrine and would therefore no longer be in full communion with the Catholic Church."[1]