In order to understand this passage on Justification, it is neccesary to take into account the context. After actually reading the entire treatise (not only the isolated cited paragraph by itself), one realizes that this Decree on Justification is undoubtly teaching that we cannot be justified without water or the will for it, since Our Lord said that we cannot be born again without water AND the Holy Spirit. We need BOTH.
The focus in the word "or" is incorrect. It is to be taken as AND. Trent had just spent paragraphs discussing how the Holy Ghost acts in the soul to cause it to cooperate and to be properly disposed for the Sacrament.
Trent was teaching the relationship between the nature of the Sacrament and the cooperation of the will, both equally needed to obtain the grace of Justification, which is only seal with Baptism. Trent was teaching against the Protestant errors. Again, Trent never taught BOD. Trent is CLEARLY teaching that BOTH the water(Sacrament) AND the cooperation / proper disposition are required for justification. Without BOTH there is no justification.
Indeed, if one tries to make the water or the desire thereof an "either ... or" proposition, then one turns the teaching of Trent into an ERROR. Because you CANNOT BE JUSTIFIED WITH WATER WITHOUT THE WILL OR DISPOSITION.
Actually, Trent anathematized those who claim that justification can happen only wih water without the cooperation of the will (votum). If someone claims that Trent teaches ONE OR THE OTHER, then he is in error, given that Trent actually condemns those that say that water alone (without the will or desire) is sufficient to justify.
Well stated, Cantarella. That EITHER/OR reading of the passage is just wrong on so many levels. Among many other things, and we've spent entire threads on the subject, it would have Trent anathematizing itself. In the Canons, Trent anathematizes the proposition that one would be justified in Baptism without the cooperation of will. And, yet, if you make Baptism / desire into an either/or concept, you would be saying that Trent taught something that it later anathematized. Which is patently absurd.
You'll notice that, when discussing Confession, Trent uses the Latin "vel ... vel" meaning either ... or. But here it does not. And in another spot (about Confession) it says "saltem in voto" (AT LEAST in desire). In this passage, Trent deliberately did NOT use these constructs ... which clearly would have indicated an either or. Consequently, the "or" after the "without" is ambiguous.
But Trent immediately disambiguates by adding, "just as it is written, unless a man be born again of water AND the Holy Spirit". As an aside, the Dimonds misinterpret this "as it is written" phrase. It means "JUST as it is written" or "according to" what is written.
I've used this example numerous times.
"Bob says that we cannot play baseball without a bat or a ball."
Let's say you didn't know anything about baseball. On the surface, this is ambiguous (and no less so in Latin). It could mean either that we can play baseball with either a bat or a ball or that we cannot play unless we have both. But now, let's add something.
"Bob says that we cannot play baseball without a bat or a ball, since we need a bat and a ball to play baseball."
Immediately disambiguated so that the without a bat or a ball clearly means that we need BOTH.
Now let's look at Trent.
"No one can be justified without the laver or the desire for it, according to what is written, no man can enter the kingdom of God unless he be born again of water AND the Holy Spirit."
Trent is making an analogy between the "laver" and Our Lord's reference to "water" and between the "desire" (=will, =proper disposition, etc.) and Our Lord's reference to the "Holy Spirit". Trent had just spent paragraphs, as Cantarella indicated, describing how the Holy Spirit works to properly move and dispose the WILL towards the fruitful reception of Baptism.
So if you can convince me that the following:
"Bob says that we cannot play baseball without a bat or a ball, since we need a bat and a ball to play baseball."
really means that we can play baseball if we have EITHER a bat OR a ball, then you will convince me that Trent taught BoD. It's that simple.
In fact, the BoDers would have Trent say:
"No one can be justified unless one be born again of water OR the desire, since Jesus taught that we need water AND the desire." You would have Trent openly contradicting the words of Our Lord.
Consequently, the notion that Trent taught BoD is just utterly absurd.
As to why someone like St. Alphonsus misread this passage. Well, he was thinking about the passages in Trent about CONFESSION. In fact, in one treatment of BoD, St. Alphonsus cited the passage on Confession as proof for BoD. So he was making an analogy and using that to disambiguate the Latin instead of seeing the phrase right afterwards and picking up on the fact that Trent was making the laver:water::votum:Holy Spirit analogy between its teaching and the words of Our Lord.
And I needn't get into the fact that, if this passage is teaching either Baptism or the votum, it actually eliminates the notion of Baptism of Blood as anything disctinct from Baptism of Desire (BoB would reduce to BoD). Yet you have quite a few Church Fathers who believed in BoB but explicitly rejected BoD, the exact inverse of what Trent taught. Consequently, everywhere you turn this interpretation of Trent leads to absurdity.