I don’t think you should be speaking of “the LXX canon [giving] way to the MT canon,” as if the Hebrew canon is a subtracted version of the Greek canon. For one, it’s highly doubtful that there was even a fixed Greek canon.
Properly speaking, the term ‘Septuagint’ really only applies to the Greek translation of the Torah/Pentateuch made during the 3rd century BC (according to an early legend by a group of seventy-two Jewish elders commissioned by a Greco-Egyptian king). Where it gets confusing is the early Church Fathers (who also came up with the term ‘Septuagint’) twisting this legend a little bit, so that now
all the sacred Jewish literature, not just the Torah, was supposedly translated into Greek by these seventy-two (or seventy) translators.
Thanks in part to the Church Fathers’ rather broad use of the term, what ‘Septuagint’ or LXX precisely means nowadays is a little fuzzy. Depending on the context or even who you ask, it could either be:
(1) The 3rd-century Greek translation of the Torah only. (The oldest Greek translations of the other biblical books would be called ‘Old Greek’ or OG. A few nitpicky scholars prefer this term.)
(2) The oldest Greek translations-versions of OT books as a whole. (The OT was translated into Greek a number of times; sometimes these translations could have multiple versions or revisions. Unlike (1), this version doesn’t distinguish between the Greek Torah and the OG versions, applying the same label to them both.)
(3) The version/s of the scriptural books favored and used by early Christians, no matter whether they were the oldest versions made or not. (For example, early Christians tended to favor the so-called
Theodontic version of Daniel than the ‘Old Greek’/‘LXX’ version.)
The problem with speaking of an ‘LXX canon’ is that it kind of assumes that the earliest Greek translations (LXX/OG) were already compiled into a fixed collection, what some people call the ‘Alexandrian canon’. But this theory really has some fatal flaws in it: (1) while this theory rests on the assumption that Hellenistic Jews were kind of disconnected from Palestinian Judaism - where the 24/39 book canon was becoming the
de facto standard - and so came up with their own idea of the canon, that doesn’t really seem to be the case. In fact, Hellenistic Jews are probably more conservative than Palestinian Jews.
(2) There’s the fact that early biblical manuscripts are really just of single books (say, a scroll of Isaiah, a scroll of Deuteronomy) or single categories of books (a Torah scroll, a scroll of the Minor Prophets). In the case of the LXX/Old Greek versions, one should probably think not of a fixed collection of translations, but
independent translations and versions circulating around. It would be Christians in the 4th-5th century who would come up with the idea of putting all these (translations of) books considered authoritative into a single volume together. It’s really telling that it’s
Christians who have produced these ‘LXX’ manuscripts.
It actually could turn out that this supposed ‘LXX/Alexandrian canon’ (which became the foundation of later Christian canons - with the exception of the Protestant one) is not actually Jewish, but a
Christian invention. In other words, we should probably be thinking of Christians taking the 24/39-book Hebrew canon - which was accepted as a
de facto standard
both by Palestinian Jews
and Hellenistic Jews - and adding further books into them. What Protestants did then is drop out those ‘extra’ books that early Christians have added into the canon.
So it pretty much all boils down to: ‘did the early Church have the authority to determine the canon of Scripture (to include* books as seen fit)’?
- Whenever you speak of the canon in an early Christian context, it’s pretty much always about ‘addition’ or ‘inclusion’. Only people considered heretics like Marcion really ‘subtracted.’
