How is baptism (sacramental or otherwise) a truth of natural reason?
How about the Trinity then?
Don't answer that. It's heresy.
Baptism is indeed a supernatural dogma, but since we know as Catholics that it is true, it is also a truth of natural reason that God will grant the effects of baptism when someone seeks to be baptized without being able to do so. If you think otherwise, then you are senseless.
When Sister of the Nativity had doubts about the validity of her baptism and feared for her salvation, Our Lord reassured her and said that not only her baptism was valid, but that she would benefit from baptism of desire if it had not been valid.
You do not understand anything about sacraments: God is free with his own laws, and when it is not possible to receive the sacraments, He can overcome that by granting the EFFECTS of the sacraments, which is the same thing as receiving the sacraments themselves.
It has already been proved that F. Feeney was condemned by Pope Pius XII himself, but you are just like the Jansenists. You American guys have protestant minds, you make your own private opinions.
As for the Trinity, I have already explained on this forum that when a pagan or a heretic is about to die, God or an angel can give him the knowledge of the Catholic dogmas so that he may be saved. In several Catholic encyclopedias, it is explained that one can belong to the soul of the Church while not belonging to her body. The theologians teach that we don't know the dispositions of the sinners (even pagans and heretics) when they die: hence it is impossible to presume their damnation. It is the teaching of the Catholic Church.
See the life of Elder Paissos, who was not a Catholic, and tell me whether he was saved or whether he was damned. Do the same with the Coptic martyrs.
Most of the so called "Catholic trads" are married men who live in carnal pleasure, and they believe that the "Orthodox" monks living in virtue are all damned while they are saved, living in pleasure.