You hit a string of nails on the head:
The Holy Spirit is the inspirer, let us say "author", of scripture in a special, unique way. He also indwells God's people. So one might say, God's people know the author, and thus recognise the authenticity of his books, That is true. The people of God, that is, the Church, had to recognise what was inspired as Scripture. What I am asking is, how is this recognition itself recognised, and your answer seem to be consensus:
In view of the unanimity and universality of this recognition, I believe it is part of - some might say the entirety of - what our Lord promised when he said the Spirit would lead the church into all truth. Whatever else it may mean, if it does include more, I believe it means this. I am aware that there have been comparitively short-lived, localised questions about the extent of the canon - excluding this, including that - but the consensus is sufficient to be persuasive.This still leaves three questions:
1) How is this consensus which decided the Canon of Scripture expressed? Is it simply the majority view of the Church? How does the Church voice its decision?
This is always the problem with non-Magisterial Protestants (i.e. other than Lutherans, Anglicans/Episcopalians, Calvinists, who have their own problems): they can never explain how they got their canon, it just is. Well, no. History shows that the canon never just was. There were plenty of "other gospels" being preached. Radical (Anabaptist etc.) Protestants reject the Protestant label, claiming that they did not take part in the Protestant Reformation. Well, they weren't around for the foundation of the Church nor the canonization of Scripture: why not eschew the label "Christian?" And out of this group came the Mormons: why reject Joe Smith's "gospel?"
2) What constitutes the boundaries of the Church whose opinion we should accept as Christian teaching?
Another problem the Radical Protestants, which they try to evade with the "Invisible church." But their "Invisible Church" was quite visible in the NT, which bears witness to that Church (i.e. us), and what they claim is the church is visible now: as Euan Cameron point out in "The European Reformation "Although the proportion of the European population rebelling against both Catholic and Protestant churches was tiny, the literature on the Radical Reformation is vast, partly as a result of the proliferation of the Radical Reformation teachings in the United States." In the United States, they are quite a political force. Why have they been hiding for over a millenium? What ever happened to not putting your light under bushel? Let that little light of mine, "I'm going to let it shine"?http://www.youtube.com/watch?v=Vnei94grw8k&feature=fvw
That city shinning on a hill?...no, if they haven't been shouting their opinion from the rooftops as the Orthodox (and indeed a myriad of heretics) have over the last two millenium, we should not take their teaching as Christ's.
3) Did the Church exist in it's fullness in the centuries before the New Testament Canon was written and decided on? And which came first, the Church or the Scriptures of the New Testament? And which, therefore, is the higher authority- the Church or the Scriptures?
That of course is the problem of sola scriptura: the earliest scriptura (I Thessalonians) witness to an already existing Church (it is addressed to the "Church of the Thessalonians") preaching our Gospel (1:5) before any of the four were penned, having "received the [yet unwritten] word in much afflication" but "from [that Church] the [yet unwritten] word has sounded forth." The second oldest writting (I Thessalonians) explicitely tells us (2:15) to "stand firm, and hold the traditions which you were taught by us [Apostles], whether by word, or by letter [i.e. only I Thessalonians]." (said Epistle (3:6) also warns us to withdraw from those who do not live "according to the Tradition that they received from" the Apostles). And although St. Paul has criticisms of the Church at Corinth (from which he wrote Thessalonians) he also did have praise (11:2): "Now I praise you, brothers, that you remember me in all things, and hold firm the traditions, even as I delivered them to you."
The Protestants take the Bible formed neither by them or for them, and then decide to create a church from their understanding of it. Scripture itself demonstrates that the Church of Christ did NOT (and does not) operate that way. This isn't a chicken or an egg question: scripture bears witness to which came first. The Church has (and if need be, could) existed without the scripture, but scripture has never (nor can it ever) existed without the Church.