And how do you know that it conforms if you don't have one of those "pre-Christian Jewish tests"? Oh, but wait a minute we do have one. It is the full book of Isaiah found at Qumran and guess what the LXX fails to conform to it.
while the Masorete deviate from them on many points.
Wrong --- the Masoretic text matches this book of Isaiah found at Qumran nearly perfectly but the LXX is way off.
They tossed out books that gave too much support to Christian positions. Hardly 'preserving the text God gave them.' The protestant insistence on the shortened canon of the Masorete strikes me quite frankly as a Judaizing heresy.
The Jews believed that part of the reason for their troubles was all the Greek books that they had brought into the synagogues and temple that were not supposed to be there. So they threw out everything written in Greek or that was not originally written in Greek. Some of these materials may have been what Jesus was referring to when he said: "by your traditions you make the law of God of no effect". They were watering down the scriptures with things that were not scripture.
Also, you are simply wrong that Origen 'composed' the fifth column of his Hexalpa.
Biblical scholars nearly all agree that he was composing and revising it as he went along using the other Greek columns to try to make it match the Hebrew in column one.
The LXX translation had been used by Greek speaking Jews from before the time of Christ.
They might have had good Greek translation of the first five books at most but there was no archetype for any of the others. Anyone who thought they knew enough Hebrew and Greek might have attempted a translation, some passages might have been good, some bad, but there was no fixed archetype before Christ or even up to Origen, merely a multiplicity of Greek translations of the OT that people called by the name "Septuagint". What people have in their hands today and call the "Septuagint" came from the 5th column of Origen which he labelled "LXX".
One question that you cannot answer is that if there actually was a certifiable Septuagint in the hands of the church and it had a long pedigree, then why was Origen revising and rewriting it in his fifth column???? Why did he have to use Aquila, Symmachus, and Theodotian for his other columns??? Why didn't he put this famous "Septuagint" there in one of those columns??? The reason was that there was no famous fixed Septuagint for him to put there. So he used the nearest thing he could find to match the Hebrew text --- and that Hebrew text had been fixed from atleast the council of Jamnia and there was no other and it was passed on to the Masoretes.
Of course there are passages where the none of the LXX, the Masorete and the Dead Sea Scroll agree. Even this calls into question the notion that rabbinic Judaism 'preserved the text God gave them,' better than the Christians, simply because they left it in Hebrew. So explain again (maybe I missed it) why Christian should follow non-Christian textual transmission, rather than the Church's judgement.
Your reply to my accusation that favoring the Masorete is a Judaizing heresy is a nonsequitur. Citing the belief of Jews on the matter, tends to confirm that view, at least as applied to your own approach to Scripture, and
Some of these materials may have been what Jesus was referring to when he said: "by your traditions you make the law of God of no effect".
is complete nonsense. The verse has a context: Christ is refering to specific customs of the Pharisees that have no support in the LXX (I've read the entire Orthodox canon of Scripture twice through: 'corban' isn't in there)--the idea that they did not need to support their parents if they dedicated their material goods to God (presumably while still enjoying them until their death, as 'sell all and give to the poor' doesn't leave anything for the support of parents either). Elsewhere, Christ condemns the Pharisaic obsession with ritual washing--again not an item drawn from the LXX.
If you want to claim that Our Lord was condemning a supposed Hellenization of Judaism, cite a specific.
I've come to the conclusion that "Biblical scholars" in your usage means protestant scholars with a short-canon agenda to defend. Can you cite any Orthodox or Latin scholars who agree? Asserting that Origen 'composed' the LXX translation of Psalms (the only part of the Hexalpa we have in fairly complete form) is problematic, given that Our Lord quotes the Psalms from the LXX, even as the Evangelist quotes from the LXX version of Isaiah, "behold a virgin shall conceive. . ." I guess your "Biblical scholars" know more about what constitutes Scripture than the Holy Evangelist Matthew. (St. Matthew, the one Evangelist who does his own textual criticism and often uses the Hebrew!)
Why did Origen do what he did in his Hexalpa? Who knows? Why did he adopt neo-Platonic ideas and hold that we would be resurrected in spherical bodies, when Christ's Glorious Resurrection showed otherwise? Origen had a lively intellectual curiosity, and a fondness for discursive reason. His beliefs and beliefs expressed in actions are not a model for sound spiritual life. The fact that he decided to collect all in one place all available versions of the Scriptures is neither here nor there as to which tradition of textual transmission Christians should follow: the Christian tradition of the Church, or the anti-Christian tradition of rabbinic Judaism.
It might be helpful to our discussions if you would explicitly acknowledge that the protestant claim that the LXX isn't a translation of Hebrew Scripture is unsupportable in view of the Hebrew texts of Tobit and Ecclesiasticus found at Qumran, and formulate precisely the position you, then, are defending as to why Christians should the Masorete to the LXX, and the arguments in favor of it.
I think I have been fairly explicit as to why the LXX is to be prefered. If you think I have been unclear, I can enumerate the points in a subsequent post.