Roman Catholic apologists maintain that the canon of Scripture was decided on during the Councils of Hippo (393 AD) and Carthage (397 AD) even though it wasn’t until the Council of Trent (1546 AD) that an infallible, binding decision was made for the Roman Catholic Church. The uncertainty over the exact canon of Scripture between the time of Hippo/Carthage and Trent goes against the assertion that the biblical canon, although not infallibly defined, was a consistent teaching in the Church that was only reaffirmed by Trent.
As the quote from Cardinal Cajetan shows, there appears to have been a dual-nature to the use of the word “canonical”. Cajetan maintains a difference between books which are to be used in confirming matters of faith and those which are simply to be read for edification. He goes on to say that understanding this distinction will help one to better understand the position of Augustine and the Council of Carthage.
In support of this idea we can look to Augustine’s own words with regards to the canon:
“Now, in regard to the canonical Scriptures, he must follow the judgment of the greater number of catholic churches; and among these, of course, a high place must be given to such as have been thought worthy to be the seat of an apostle and to receive epistles. Accordingly, among the canonical Scriptures he will judge according to the following standard: to prefer those that are received by all the catholic churches to those which some do not receive. Among those, again, which are not received by all, he will prefer such as have the sanction of the greater number and those of greater authority, to such as are held by the smaller number and those of less authority. If, however, he shall find that some books are held by the greater number of churches, and others by the churches of greater authority (though this is not a very likely thing to happen), I think that in such a case the authority on the two sides is to be looked upon as equal.
Now the whole canon of Scripture on which we say this judgment is to be exercised, is contained in the following books…”
-Augustine, On Christian Doctrine, Book II, Ch. 8
It is interesting to note that prior to giving his list of canonical books, Augustine outlines how one should decide which books are canonical. There are three main issues here.
First, it does not seem that Augustine was establishing what IS canonical since he is providing a method to determine canonicity to the reader. Second, it appears there was not a consensus of canonicity at the time of Augustine’s writing since he is providing a method for determination of such. And third, after advising the reader how to determine canonicity, Augustine goes on to describe “the whole canon of Scripture on which we say this judgment is to be exercised” (which is the canon lists of Hippo/Carthage) meaning that the canon list of those Councils is still up for discussion.
Taking the quotes of Cardinal Cajetan and Augustine together, it appears that the canon lists of the early councils led by Augustine were establishing a list of Scriptures from which the canonical Scriptures could be determined based on the consensus of Church usage (using the method outlined by Augustine). Effectively, Augustine and the Councils had narrowed the list of potentially canonical books without strictly defining the exact nature of the biblical canon. This would explain why discussion and doubts about the canonical books continued from the time of Augustine until the time of Trent.