“There are those who claim that Baptism of Blood, and that Baptism of Water is the only means of salvation. This is a serious error. The Church does indeed teach that Baptism of Desire and Baptism of Blood are means of salvation to those who through no fault of their own have not received Baptism of Water, but who have the efficacious (working on it) desire to enter the Catholic Church or who give their life for the name of Our Blessed Lord, Jesus Christ. The Council of Trent when defining justification made it clear that the desire spoken of here has to do with the desire to receive the Sacrament of Baptism, not some kind of independent entities excluding the Baptism of Water. This doctrine has been given much clarification by Pope Pius IX and again by Pope Pius XII. It is addressed again at this time to crush the recent proliferation of the error that Baptism of Desire and Baptism of Blood do not exist, and to put this new resistance to these truths, to rest.”
In the Council of Florence, that was held in the fifteenth century, there was no mention of Baptism of Desire and Baptism was absolutely essential for salvation:
“The positive document: ‘The Decree for the Armenians’
‘The Decree for the Armenians’, in the Bull ‘Exultate Deo’ of Pope Eugene IV, is often referred to as a decree of the Council of Florence. While it is not necessary to hold this decree to be a dogmatic definition of the matter and form and minister of the sacraments, it is undoubtedly a practical instruction, emanating from the Holy See, and as such, has full authenticity in a canonical sense. That is, it is authoritative. The decree speaks thus of Baptism:
Holy Baptism holds the first place among the sacraments, because it is the door of the spiritual life; for by it we are made members of Christ and incorporated with the Church. And since through the first man death entered into all, unless we be born again of water and the Holy Ghost, we can not enter into the kingdom of Heaven, as Truth Himself has told us. The matter of this sacrament is true and natural water; and it is indifferent whether it be cold or hot. The form is: I baptize thee in the name of the Father and of the Son and of the Holy Ghost. We do not, however, deny that the words: Let this servant of Christ be baptized in the name of the Father and of the Son and of the Holy Ghost; or: This person is baptized by my hands in the name of the Father and of the Son and of the Holy Ghost, constitute true baptism; because since the principal cause from which baptism has its efficacy is the Holy Trinity, and the instrumental cause is the minister who confers the sacrament exteriorly, then if the act exercised by the minister be expressed, together with the invocation of the Holy Trinity, the sacrament is perfected. The minister of this sacrament is the priest, to whom it belongs to baptize, by reason of his office. In case of necessity, however, not only a priest or deacon, but even a layman or woman, nay, even a pagan or heretic can baptize, provided he observes the form used by the Church, and intends to perform what the Church performs. The effect of this sacrament is the remission of all sin, original and actual; likewise of all punishment which is due for sin. As a consequence, no satisfaction for past sins is enjoined upon those who are baptized; and if they die before they commit any sin, they attain immediately to the kingdom of heaven and the vision of God.”
By the time we get to the Council of Trent need is felt to introduce some flexibility. This is what the Catholic Encyclopedia has to say about the canons of Baptism, coming from the Council of Trent:
“The negative document: ‘De Baptismo’
The negative document we call the canons on baptism decreed by the Council of Trent (Sess. VII, De Baptismo), in which the following doctrines are anathematized (declared heretical):
The baptism of John (the Precursor) had the same efficacy as the baptism of Christ,
True and natural water is not necessary for baptism, and therefore the words of Our Lord Jesus Christ “Unless a man be born again of water and the Holy Ghost” are metaphorical.
The true doctrine of the sacrament of baptism is not taught by the Roman Church,
Baptism given by heretics in the name of the Father and of the Son and of the Holy Ghost with the intention of performing what the Church performs, is not true baptism,
Baptism is free, that is, not necessary for salvation.
A baptized person, even if he wishes it, can not lose grace, no matter how much he sins, unless he refuses to believe.
Those who are baptized are obliged only to have faith, but not to observe the whole law of Christ.
Baptized persons are not obliged to observe all the precepts of the Church, written and traditional, unless of their own accord they wish to submit to them.
All vows made after baptism are void by reason of the promises made in baptism itself; because by these vows injury is done to the faith which has been professed in baptism and to the sacrament itself.
All sins committed after baptism are either forgiven or rendered venial by the sole remembrance and faith of the baptism that has been received.
Baptism although truly and properly administered, must be repeated in the case of a person who has denied the faith of Christ before infidels and has been brought again to repentance.
No one is to be baptized except at the age at which Christ was baptized or at the moment of death.
Infants, not being able to make an act of faith, are not to be reckoned among the faithful after their baptism, and therefore when they come to the age of discretion they are to be rebaptized; or it is better to omit their baptism entirely than to baptize them as believing on the sole faith of the Church, when they themselves can not make a proper act of faith.
Those baptized as infants are to be asked when they have grown up, whether they wish to ratify what their sponsors had promised for them at their baptism, and if they reply that they do not wish to do so, they are to be left to their own will in the matter and not to be forced by penalties to lead a Christian life, except to be deprived of the reception of the Eucharist and of the other sacraments, until they reform.
The doctrines here condemned by the Council of Trent, are those of various leaders among the early reformers. The contradictory of all these statements is to be held as the dogmatic teaching of the Church.”