"How exactly does He do that? Because He cites a few sayings from what WE NOW recognize as Scriptures? Does He take aside the Sadducees and tell them that they are wrong to accept ONLY the Torah? Does Jesus lay out the entire Canon?"
Actually He does. In speaking to the religious leaders who would be using the Hebrew Canon, He says, (John 5:39), "Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."
As Josephus, the renegade, traitor Jew, sycophant of the Emperors Flavius and Titus wrote soon after Christ, Josephus said "Although so great a time interval has now passed, not a soul has ventured to add or remove or to alter a syllable, and it is the instinct of every Jew, from the day of his birth, to consider these Scriptures as the teaching of God, to abide by them, and, if need be, to cheerfully lay down his life in their behalf." His enumeration and description of these books show that they were the same as those of the Old Testament as we now have it.
There has always been tension in the early church between the Greek speaking Christians and the septuagint and the Jewish christians and the Hebrew Canon. The Gentile Christians as can be expected used the septuagint since it was in their language and Rome, in moving to solidify its political and religious power, used it to remove the "jewishness" of the church.
You are avoiding my question. How does Jesus take the Sadducees aside and tell them that the Torah is NOT the total Scriptures??? John 5:39 can just as easily be interpreted to say that Jesus AGREES with their idea of Scriptures being 5 books - and then to go search THEM to find that they testify to Him... He doesn't tell them that they need to search the "Pharisees' version" of the Scriptures.
As Josephus, the renegade, traitor Jew, sycophant of the Emperors Flavius and Titus wrote soon after Christ, Josephus said "Although so great a time interval has now passed, not a soul has ventured to add or remove or to alter a syllable, and it is the instinct of every Jew, from the day of his birth, to consider these Scriptures as the teaching of God, to abide by them, and, if need be, to cheerfully lay down his life in their behalf." His enumeration and description of these books show that they were the same as those of the Old Testament as we now have it.
You have described for me the Pharisee opinion of the Canon. Wonderful. Now, what about the Saduccee or the Essene opinion? Again, Josephus didn't speak for the entire Israeli nation when he wrote for the Romans
There has always been tension in the early church between the Greek speaking Christians and the septuagint and the Jewish christians and the Hebrew Canon. The Gentile Christians as can be expected used the septuagint since it was in their language and Rome, in moving to solidify its political and religious power, used it to remove the "jewishness" of the church.
Speculation not based on the evidence at hand. You are presuming there WAS a Hebrew Canon that was widely accepted by all Jews. This was not the case until well into the Second Century. Research and the Bible tells us there was NOT a monolithic Canon accepted by Jews. The Diasporan Jews were Jewish as well as the Palestinean Jews. Modern research has also determined that the Septuagint was utilized in Palestine, not just in the Diaspora. Thus, your premise is unacceptable. The fact of the matter is that the majority of Jews were using the Septuagint during the time of Christ. More Jews lived OUTSIDE of Palestine than within. They used the Septuagint. Some Palestinean Jews ALSO used the Septuagint. Thus, it would only be natural for the JEWISH writers of the NT to use the most-used "version" of Scripture, the Septuagint. They found within the Septuagint verses that could be applied to Christ that were not as clearly marked in what we now call the Hebrew Canon (which was not the only Hebrew version of Scriptures).
Remember, also, the Old Testament in your Christian Bible (at least those based on the KJV) is dependent upon the Masoretic tradition, not the original Hebrew autographs. The Dead Sea scrolls bear a closer resemblance to the Septuagint than the Masoretic texts on many occasions.
Regards
The Gentile Christians as can be expected used the septuagint since it was in their language and Rome, in moving to solidify its political and religious power, used it to remove the "jewishness" of the church
Goodness! Alexandrian and Asia Minor Jews were hellenized and spoke only Greek. The Septuagint was originally translated, some two hundred years before Christ, by Jewish scholars, for the Alexandrian Jews who spoke only Greek and could not understand Hebrew Scriptures.
Removing "jewishness" was against 'judaizing' and it had nothing to do with Septuagint.