If I may a few facts on St Thomas, from the Dimonds book , "Outside the Church There is absoultly No Salvation"...
ST. THOMAS AQUINAS
St. Thomas Aquinas, despite all of his fabulous writing and learning about the Catholic Faith, being a fallible human being, was wrong on many points, including his explicit statement in the Summa Theologica that “The flesh of the Virgin was conceived in Original Sin.”[ccxli] One scholar noted that the book St. Thomas was writing when he died was called The Compendium of Theology, in which are found at least nine explicit errors.[ccxlii] In fact, “over thirty years ago, Dr. Andre Daignes, Professor of Philosophy in Buenos Aires, Argentina, pointed out twenty-four formal errors in the Summa of St. Thomas.”[ccxliii] This simply proves again that the theological speculations of even our greatest sainted theologians are just that – fallible speculations. Only St. Peter and his successors, the popes, when speaking from the Chair of Peter, have the unfailing faith.
Pope Pius IX, Vatican Council I, ex cathedra:
“So, this gift of truth AND A NEVER FAILING FAITH WAS DIVINELY CONFERRED UPON PETER AND HIS SUCCESSORS IN THIS CHAIR…”[ccxliv]
In Summa Theologica III, Q. 66, Art. 11, St. Thomas tries to explain his belief in baptism of desire and blood. He tries to explain how there can be “three baptisms” (water, blood and desire) when St. Paul declares in Ephesians 4:5 that there is only one. He says:
“The other two Baptisms are included in the Baptism of Water, which derives its efficacy, both from Christ’s Passion and of the Holy Ghost.”[ccxlv]
With all due respect to St. Thomas, this is a feeble attempt to answer the objection as to how there can be “three baptisms” when God reveals that there is only one. It is feeble because St. Thomas says that the other two baptisms, desire and blood, are included in the baptism of water; but this is false. One who receives baptism of water doesn’t receive baptism of desire and baptism of blood, even according to the baptism of desire advocates. Therefore, it is false to say, as St. Thomas does, that the other two baptisms are included in the baptism of water; they most certainly are not.
Furthermore, in teaching the theory of baptism of desire, St. Thomas repeatedly admitted that neither is a sacrament.
St. Thomas Aquinas, Summa Theologica III, Q. 66, A. 11, Answer 2: “As stated above, a sacrament is a kind of sign. The other two [baptism of desire and blood], however, are like the Baptism of Water, not, indeed, in the nature of sign, but in the baptismal effect. Consequently they are not sacraments.”[ccxlvi]
The fierce baptism of desire advocate, Fr. Laisney, admits the same in his book, Is Feeneyism Catholic?, p. 9:
Fr. Laisney, Is Feeneyism Catholic?, p. 9: “Baptism of Desire is not a sacrament; it does not have the exterior sign required in the sacraments. The theologians, following St. Thomas… call it ‘baptism’ only because it produces the grace of baptism… yet it does not produce the sacramental character.”[ccxlvii]
But the Council of Trent (a few centuries after St. Thomas, in 1547) infallibly defined as a dogma that THE SACRAMENT OF BAPTISM is necessary for salvation!
Pope Paul III, The Council of Trent, Can. 5 on the Sacrament of Baptism, ex cathedra: “If anyone says that baptism [the sacrament] is optional, that is, not necessary for salvation (cf. Jn. 3:5): let him be anathema.”[ccxlviii]
So, whom does one follow, St. Thomas or the infallible Council of Trent? Compare the two:
St. Thomas Aquinas, Summa Theologica III, Q. 68, Art. 2: “… it seems that a man can obtain salvation without the sacrament of Baptism, by means of the invisible sanctification…”
Pope Paul III, The Council of Trent, Can. 5 on the Sacrament of Baptism, Sess. 7, 1547, ex cathedra: “If anyone says that baptism [the sacrament] is optional, that is, not necessary for salvation (cf. Jn. 3:5): let him be anathema.”[ccxlix]
There is an obvious contradiction here. The fallible St. Thomas Aquinas says that it is possible to obtain salvation without the Sacrament of Baptism, while the infallible Council of Trent defines that the sacrament is necessary for salvation. And what does “necessary” mean? According to Part III, Q. 68, A. 2, Obj. 3 in St. Thomas’ own Summa Theologica, “that is necessary without which something cannot be (Metaph. V).”[ccl] Thus, “necessary” means without which something cannot be. Thus, salvation cannot be – it is impossible – without the Sacrament of Baptism (de fide, Council of Trent). Catholics must accept this truth and reject St. Thomas’s fallible opinion in the Summa Theologica on baptism of desire.
Pope Benedict XIV, Apostolica (# 6), June 26, 1749: “The Church’s judgment is preferable to that of a Doctor renowned for his holiness and teaching.”[ccli]
Pope Pius XII, Humani generis (# 21), Aug. 12, 1950:
“This deposit of faith our Divine Redeemer has given for authentic interpretation not to each of the faithful, not even to theologians, but only to the Teaching Authority of the Church.’”