Where does the idea that there are only two ex cathedra statements come from?

Many contemporary Catholic commentators claim that there have been only two ex cathedra statements in history—Ineffabilis Deus (1854, on the Immaculate Conception) and Munificentissimus Deus (1950, on the Assumption). Yet the Relatio of Bishop Vincent Gasser at Vatican I (1870)—the official interpretive document for Pastor Aeternus—insists that papal infallibility had already been exercised “thousands and thousands of times.” This document was appended to the council’s acts and cited again at Vatican II. If the magisterial tradition acknowledges repeated infallible teachings, why does the notion of “only two ex cathedra statements” persist? Where does this restricted interpretation originate? Requested excerpts from the Relatio: > (30). But some will persist and say: "[...] let us also define the form to be used by the Pontiff in such a judgment." It seems to me that this was the mind of some of the most reverend fathers as they spoke from this podium. But, most eminent and reverend fathers, **this proposal simply cannot be accepted because we are not dealing with something new here. Already thousands and thousands of dogmatic judgments have gone forth from the Apostolic See; where is the law which prescribed the form to be observed in such judgments?**" > (90). In this definition we treat: (01) the subject of infallibility, namely the Roman Pontiff as Pontiff, i.e., **as a public person in relation to the Universal Church.** (02) There is contained in the definition the act, or the quality and condition of the act of an infallible pontifical definition, i.e., the Pontiff is said to be infallible when he speaks "ex cathedra." This formula is received in the schools, and the meaning of this formula as it is found in the very body of the definition is as follows: when the supreme Pontiff speaks "ex cathedra," **not, first of all, when he decrees something as a private teacher, nor only as the bishop and ordinary of a particular See and province, but when he teaches as exercising his office as supreme pastor and teacher of all Christians.** Secondly, not just any manner of proposing the doctrine is sufficient even when he is exercising his office as supreme pastor and teacher. Rather, **there is required the manifest intention of defining doctrine, either of putting an end to a doubt about a certain doctrine or of defining a thing, giving a definitive judgment and proposing that doctrine as one which must be held by the Universal Church.** ... Some common examples of statements that clearly passs the "Gasser test" for infalliblity. > **Furthermore, we declare, we proclaim, we define that it is absolutely necessary for salvation that every human creature be subject [both spiritually and temporally; see prev. paragraphs] to the Roman Pontiff.** > > — Unam Sanctam, *Bull of Pope Boniface VIII promulgated November 18, 1302* Included in _Sources of Catholic Dogma, 'Denzinger'_, see 468 and 469 1. In discharge of the office of pastor and doctor of all Christians, in virtue of his supreme Apostolic authority: The document is an authoritative papal bull. 2. Defines a doctrine: "we declare, we proclaim, we **define**…" 3. Regarding faith or morals: Yes. He speaks about what is necessary for salvation. 4. To be held by the universal Church: Bulls are addressed to the whole Church. > The most Holy Roman Church firmly believes, professes and preaches [...] that no one existing outside the Catholic Church, not only pagans, but also Jews or heretics and schismatics, can become partakers of eternal life, but will go into _the eternal fire_ _prepared for the devil and his angels_, unless they are gathered to it before the end of life, and that the unity of the ecclesiastical body is so strong that only those who remain in it benefit from the ecclesiastical sacraments and fasting, almsgiving and other offices of piety and exercises of the Christian soldiery bring forth eternal rewards, and that no one, no matter how much alms he gives and if he sheds blood for the name of Christ, can be saved unless he remains in the bosom and unity of the Catholic Church. > > — Cantate Domino, *Bull of Pope Eugene IV, February 4, 1442, Council of Florence* Included in _Sources of Catholic Dogma, 'Denzinger'_, see 703 to 715 1. In discharge of the office of pastor and doctor of all Christians, in virtue of his supreme Apostolic authority: The document is an authoritative papal bull. 2. Defines a doctrine: The necessity of submission to the Roman Church for salvation. 3. Regarding faith or morals: Yes. He speaks about what is necessary for salvation. 4. To be held by the universal Church: Bulls are addressed to the whole Church. Additionally, Wikipedia lists five others: 1. *Tome to Flavian*, by Pope Leo I (449), on the two natures in Christ, received by the Council of Chalcedon. 2. Letter of Pope Agatho (680), on the two wills of Christ, received by the Third Council of Constantinople. 3. *Benedictus Deus*, by Pope Benedict XII (1336), on the beatific vision of the just after death rather than only just prior to the final judgment. 4. *Cum occasione*, by Pope Innocent X (1653), condemning five propositions of Cornelius Jansen as heretical. 5. *Auctorem fidei*, by Pope Pius VI (1794), condemning several Jansenist propositions of the Synod of Pistoia as heretical.