Diamond:
I think perhaps, because he was giving a theological opinion on the Book of Job, as I remember, and making a view that again reflects his personal opinion as to 1 Macabees. Gregory was a Monk and perhaps he personally questioned whether 1 Macabees was canonical, which is the best explanation as he never convened a Council to review the question of the Canon. Regardless, the II Council at Nicea in 787 AD reaffirmed the Councils of Carthage in 419 and Trent only reaffirmed, again a Council the earlier Council decisions. So, Pope Gregory’s personal view of 1 Macabees never was binding on the Church. And, to be accurate, the Catholic Church does distinguish between the Protocanonical books and Deuterocanonical, but note distinguish does mean that we separate them. So, perhaps Pope Gregory was making a case to overly distinguish the fact that 1 Macabees did not enjoy the same status as the Book of Job, at least in his Opinion speaking as a Theologian, not speaking as Pope at a Council that intended to challenge the earlier Councils of the 4th and 5th century [Rome 382, Hippo 393, Carthage 397, Carthage again in 419, etc]
In additio, I don’t dispute that there were other Deuterocanonicals that were sometimes viewed as part of the Canon. THe Septuigiant has 2 other books tha were part of the Deuterocanonicals [3 and 4 Macabees] and If I am not mistaken, some of the Eastern Orthodox Churches accept those at part of the OT canon. In other words, the Catholic Canon while now limited to 46 OT books, the 39 that Protestants have in their OT canon plus the 7 Deuterocanonicals [Wis, Sir, Tob, Baruch, 1 and 2 Macabees, Judith], is somewhat smaller than the Russian, Greek, Serbian, Ukrainaian and Armenian Eastern Orthodox Churches.
So what we actually have in Christendom is 3 Old Testament Canons. The Catholic OT canon, the Eastern Orthodox OT Canon and the Protestant OT canon, and while the Catholic and Eastern Orthodox OT canons do not agree exactly, they are pretty close relying on the LXX whereas the Protestant OT canon is the outlier among the 3 OT canons.
Now, I would like to add some commentary on the Canon and the Church Father based on the writings of Pope Benedict. In his book entitled “Principles of Catholic Theology: Building Stones For a Fundamental Theology”, the Pope in Chapter 2, entitled Scripture and Tradition, lays out the case for Sacred Scripture and Sacred Tradition, as expressed in the Creeds of the Church, the Liturgy and writings of the Church Fathers, and how they are all important in building a foundation for orthodox doctrine.
Now, with respect to the Church Fathers, which I have cited extensively in some of my other posts in this thread, Pope Benedict (pp. 148-151) makes some interesting points. First, The Canon of Holy Scripture can be traced back to them, or at least to the undivided Church of the first centuries, of which they were the representatives. It is through their [The Church Fathers] efforts that precisely those “books” that today we call “New Testament” were chosen from a multitude of other available literary texts and that the “Greek version of the OT” [i.e. the Septuiagint] was joined to them, that it was interpreted in terms of them, and together became known as “Holy Scripture”
The Pope continues [and this is I think an important point] and notes that a book was recognized as “canonical” if it was read in the Liturgy of the Church [public worship]. By Church, the Pope notes that it means that the numerous Eastern Churches had their own lists and customs, but in the end, all came to accept the same set of books [with some minor distinctions with respect to 3 and 4 Macabees]. The Pope notes of the Gnostic texts, which aspired to become scripture but states that it was the anti-Gnostic Church Fathers whose writings against the Gnostics drew the line in the Church. In summary, the canon, as canon, would be inconceivable without the intellectual movement to which patristic theology bears witness.
Second, in addition to the Bible, the Church Fathers were instrumental in formulating the important symbola of all Christendom [ie. the Creeds and Confessions of Faith] and Finally, in the ancient undivided Church, the reading of Sacred Scripture and the confession of faith [Creeds] were primarily Liturgical acts of the whole assembly gathered around the Risen Lord. Thus, the Pope notes, it was the ancient Church, and thus the Fathers, that created the fundamental forms of Christian Liturgy
So, for the Catholic and Eastern Orthodox Church, I think Pope Benedict is pointing out that a book suitable for public worship is just as important a principle for canonicity as is whether the Book was important for determining Doctrine. Hence, perhaps Pope Gregory’s comment regarding 1 Macabees could also be seen in that context, it was appropriate for Reading in the Liturgy as it remined how faithful Judas Macabees was in trying to drive out the pagans from Jerusalem and the Temple and that applies to us today.
Yet, he wrote the commentary as bishop of Rome, and his commentary was used into the later Middle Ages as the standard commentary on Job for the entire Western Church, so I don't think it can be regarded as merely his personal opinion. While he did teach that the book was useful for edification, along the lines of Jerome, the fact remains that his denial of 'strict' canonical status to 1 Maccabees long after the Councils of Hippo and Carthage is in direct contradiction to what the earlier Roman Church decreed under Innocent I, who confirmed the books sanctioned as canonical by the Councils of Hippo and Carthage. It is inconceivable to me that Gregory the Great would have ever purposefully expressed a view that he knew was contrary to that which had been authoritatively established by the Church.
With regard to Nicea II, that Council also reaffirmed the canons of the Trullan Council called the Quinisext Council, and in doing so affirmed the canons of Athanasius, Amphilocius and Basil the Great on the canon, all of whom rejected the majority of the Deuterocanonical books as being canonical. See Canon 1:
"... and those both of the six holy Ecumenical Councils and of the ones assembled regionally for the purpose of setting forth such edicts, and of those of our holy Fathers...’which is a direct reference to the Quinisext/Trullan Council. Nicea II considered the decrees of the Council of Trullo to have promulgated decrees of the Sixth Ecumenical Council.
The Pope continues [and this is I think an important point] and notes that a book was recognized as “canonical” if it was read in the Liturgy of the Church [public worship]. By Church, the Pope notes that it means that the numerous Eastern Churches had their own lists and customs, but in the end, all came to accept the same set of books [with some minor distinctions with respect to 3 and 4 Macabees]. The Pope notes of the Gnostic texts, which aspired to become scripture but states that it was the anti-Gnostic Church Fathers whose writings against the Gnostics drew the line in the Church. In summary, the canon, as canon, would be inconceivable without the intellectual movement to which patristic theology bears witness.
Don't forget 'Greek Esdras (Septuagint Esdras I) which was accepted for the first five centuries of the Church, and then excluded at Trent. It seems to me, though, that either the Councils were contradicting themselves, or, and you allude to it, there were two senses of the term 'canonical', and that the deuterocanonical books were not to be regarded as canonical in the strict sense, but were to be regarded as useful for edification and reading in the Churches.
Cordially,