I have seen and heard the statement quoted by many good theologians and Catholic sites. In fact, I am all but sure it is true, as I have done all but read it out of the original manuscript. The definition was also made at Florence. Both Florence and Lyons II infallibly declared that those who die in Original Sin descend immediately into Hell. We know for a fact that an infant cannot be forgiven Original Sin without Baptism. This has been proved invincibly by the Fathers and the Councils of the Church. The Catechism of the Council of Trent says it very clearly:
“If then through the transgression of Adam, children inherit original sin, with still stronger reason can they attain through Christ our Lord grace and justice that they may reign in life. This however, cannot be effected otherwise than through baptism. Pastors therefore should inculate the absolute necessity of administering baptism to infants, and of gradually forming their minds to piety by education in the Christian religion… The faithful are earnestly to be exhorted to take care that their children be brought to the Church , as soon as it can be done with safety, to receive solemn baptism. Since infant children have no other means of salvation except baptism, we may easily understand how grievously those persons sin who permit them to remain without the grace of the sacrament longer than necessity may require, particularly at an age so tender as to be exposed to numberless dangers of death.”
Moreover, the quote is listed THREE times in Denzinger: 464, 493a, and 693. I will type them here right from my own Denzinger book:
GREGORY X 1271-1272
COUNCIL OF LYONS II 1274
Ecumenical XIV (concerning the union of the Greeks)
464 "We believe that the true Church is holy, Catholic, apostolic, and one, in which is given one holy baptism and true remission of all sins. We believe also in true resurrection of this flesh, which now we bear, and in eternal life. We believe also that the one author of the New and the Old Testament, of the Law, and of the Prophets and the Apostles is the omnipotent God and Lord. This is the true Catholic Faith, and this in the above mentioned articles the most holy Roman Church holds and teaches. But because of diverse errors introdcued by some through ignorance and by others from evil, it (the Church) says and teaches that those who after baptism slip inot sin must not be rebaptized, but by true penance obtain forgiveness of their sins. Because if they die truly repentant in charity before they have made satisfaction by worthy fruits of penance for (sins) comitted and omitted, their souls are cleansed after death by purgatorical or purifying punishments, as Brother John (footnote 1) has explained to us. And to relieve punishments of this kind, the offerings of the living faithful are of advantage to these, namely, the sacrifices of Masses, prayers, alms, and other duties of piety, which have customarily been performed by the faithful for the other faithful according to the regulations of the Church. However, the souls of those who after having received holy baptism have incurred no stain of sin whatever, also those souls who, after contracting the stain of sin, either while remaining in their bodies or being divested of them, have been cleansed, as we have said above, are received immediately into heaven. The souls of those who die in mortal or with original sin only, however, immediately descend to hell, yet to be punished with different punishments. The same most holy Roman Church firmly believes and firmly declares that nevertheless on the day of judgment “all” men will be brought together with their bodies “before the tribunal of Christ” “to render an account” of their own deed [Rom. 14:10].
(footnote 1) Brother John Parastron, O.F.M.
I have not added anything whatsoever to the above quotation except the bolding of the matter in question.
The teaching appears again, 493a:
“It (The Roman Church) teaches . . . that the souls . . . of those who die in mortal sin, or with only original sin descend immediately into hell; however, to be punished with different penalties and in different places.”
I have added nothing to this, either. It is from: “Hell and Limbo (?) (footnote 1) [From the letter “Nequaquam sine dolore” to the Armenians, Nov. 21, 1321]”
(footnote 1) Bar(Th) approximately the year 1321, n. II. Cf. Zeitschr. f. kath. Theologie 52 (1928): 79 ff. (A Straub); Estudios ecclesiásticos 5 (1926): 438 ff. (F. Segarra).
Finally, this teaching is seen in 693 (see next post)