A few weeks ago, one of the authors of Called to Communion wrote a blog post exploring John Calvin’s statements with regard to knowing the canon of Scripture (e.g. which books comprise the Bible). There are now over 200 comments on this post, mainly a Reformed Protestant named Andrew M. going back and forth with two of the Called to Communion authors: Tim and Bryan, both formerly Reformed Protestants, though Yours Truly also weighed in a few times with some commentary.
Calvin’s arguments on this question are not the strongest, which at least one of the Protestant commenters sought to defend by saying that Calvin in this passage was perhaps not attempting to refute the Catholic Church’s arguments directly but just laying out his ideas for how a Christian can know what books should be in the Bible “in general”.
Here is an excerpt from Calvin:
It is utterly vain, then, to pretend that the power of judging Scripture so lies with the church and that its certainty depends upon churchly assent….Whence will we learn to distinguish light from darkness, white from black, sweet from bitter? Indeed, Scripture exhibits fully as clear evidence of its own truth as white and black things do of their color, or sweet and bitter things do of their taste.
Let this point therefore stand: those whom the Holy Spirit has inwardly taught truly rest upon Scripture, and that Scripture indeed is self-authenticated…
In other words, a true Christian does not need the Church or any church to tell him what makes up Scripture because the true Scriptural books themselves so clearly testify to their God-inspired truth that the Christian, with the Holy Spirit, can easily discern what is Scripture and what is not, as easily as discerning white from black, sweet from bitter.

John Calvin
Note for our readers: “Reformed” Protestants are those whom most closely associate themselves with John Calvin’s teachings (and Martin Luther’s), as opposed to, for instance, Zwingli or the “radical” Reformers (e.g. Anabaptists and others). I think that most Reformed Christians go to some type of Presbyterian church. “Reformed” can be contrasted with “Evangelical” Protestants, who are typically Baptist, Fundamentalist, non-denominational, or Bible-church Christians. Evangelicals take their Protestant heritage more from the so-called “radical Reformers”, like the Anabaptists, who rejected many things that even Calvin and Luther held as true, causing enmity between these sets of Reformers.
In the comments, Reformed Protestant Andrew M. is arguing that he knows the canon “infallibly” or “inerrantly”, that is, he knows with 100% confidence which books comprise the Bible, and those books are the 66 which make up the Protestant Bible, as opposed to the 73 which make up the Catholic Bible. Catholics Bryan and Tim challenged Andrew to demonstrate how he knows that the Protestant canon was inerrant, which Andrew so far has failed to do.
Andrew’s main arguments thus far have been 1) the 7 deutero-canonical (DC) books included in the Catholic Bible were not accepted by various specific Catholic theologians and Fathers over the centuries leading up to the Reformation, and 2) The fact that the Bible tells us that the Scriptures are “God-breathed” means that God both inspired men to write these books and also that, inseparably connected with their inspiration, God also infallibly “oversaw” the collection of these precise books by “the Church”.

Presbyterianism
Bryan and Tim have rightly demonstrated that Andrew’s arguments don’t actually give assurance that the 66-book Protestant canon is inerrant. His arguments can certainly be discussed on their own grounds, but they do not provide an answer to the question of how a Protestant can know his canon is inerrant.
The problem with Andrew’s second argument, as I see it, is that it ignores the historical reality of how the canon was selected. It was not an easy, clear process without debate that ended in the 2nd century. If that were the case, all Christians would agree on whatever canon was chosen then. Rather, the laborious process took hundreds of years after the Apostles’ deaths for the canon to slowly emerge, with differing canons being proposed by different Fathers and bishops during these centuries. The canon agreed upon by the Church around 400 AD, though not yet dogmatically, was comprised of the 27 New Testament books and the 46 Old Testament books, including the 7 deutero-canonicals. However, there were Catholic theologians over the centuries who debated whether the deuteros (and others) should be included, and ultimately, over 1100 years later, the Reformers decided that the 7 deuteros were not as well attested as inspired, and so though they included them in their Bible, they were not to be regarded with the same weight as the other 66. (Ultimately, as the centuries passed these 7 books were removed entirely from Protestant Bibles.) During this time of the Reformation, in the Council of Trent, the Catholic Church dogmatically stated that the canon was comprised of the 73 books and that the canon was closed.
So the very fact that varying degrees of disputation and discussion occurred within the Church for the first 400 years of Christianity and then again 1100 years later by the Reformers repudiates Andrew’s assertion that the inspiration of the Scriptural books and their collection into the canon were one “God-breathed” process. They were not. As is the ordinary way with God, He chose to work through his very fallible, sinful yet redeemed human disciples in guiding them to discern which books He had inspired and which He had not. That God oversaw the process and guided it, Catholics completely agree, but the reason Catholics can know that the 73 book canon is inerrant is because God, by His awesome power and grace, has divinely protected His Church from error on matters of the faith from Pentecost when she was born up to and including the present day.
Protestants are not able to appeal to the same belief, though in practice they cherry-pick certain teachings the Church discerned as true over the centuries. If Protestants hold that God had divinely protected the Church from error in selecting the canon, several problems arise for them:
1. Why then didn’t He also protect other teachings from error (baptismal regeneration, the Real Presence in the Eucharist, intercession of saints, Purgatory, and so on, which were all already taught by the 400s)?
2. Where in the Bible does it say that God will protect His Church from error when selecting the canon but not in other matters? (And since it doesn’t say this, how is this belief not an extra-biblical and therefore human tradition which Jesus condemned?)
3. Since Protestants reject 7 books that the Church discerned were inspired, it means they also have to believe that the Catholic Church was mostly protected from error in the 400s when selecting the canon but then for 1100 years the error of the deuteros was taught before the Reformers (also infallibly guided by God?) removed those 7 books.

Painting of a scene from the book of Tobit, one of the 7 deutero-canonicals
That is why the two other options for Protestants are those which, in my experience, are most often taken in practice:
1. The canon is a “fallible collection of infallible books” coined by R.C. Sproul–this belief admits that the canon of the very Bible itself, which Protestants hold as the highest authority (sola Scriptura), very possibly contains books which were not inspired by God and others which were inspired but which have been left out! A dissatisfying proposition to say the least.
2. Ignore history and just assert “I believe that God ‘miraculously’ protected the canon from error and that the canon is the 66 books of the Protestant Bible. I KNOW this because the Bible has meant so much to me in changing my life.”
This second option eshews the use of reason and just makes a fideistic assertion without any basis except in the private feelings and intuition of the individual Christian. It cannot be discussed or debated because it is not an actual argument.
Why didn’t God make the canon obvious? I don’t know. He certainly could have done so, such that, as Calvin implied, any true Christian could just read a particular book and “tell” that the book was inspired. But God did not do that, as is clear from the fact that faithful Christians have disagreed about the canon for centuries and that we have two sets of canons today, the Catholic one and the Protestant one.
Ultimately, for me it is yet another reason to believe that God has protected His Church from error and led her into all truth, not by the piety nor brilliance alone of these very fallible human beings, but rather by His unmerited grace and love; He did not and does not want His children to be led astray by falsehood, which is why He inspired books to be written in the first place! He wants us to know the truth and to be able to know truth from falsehood, which is why He not only inspired a certain number of books to be written, but also then guided His Church, which is the Bride of Christ, in correctly discerning which of the hundreds of letters being circulated were divinely inspired and which were not. And if He guided the Church inerrantly on this matter, then we have every reason to believe He did it on other matters, like the divinity and humanity of Christ (both attacked), the nature of the Trinity and the relationship of the Father to the Son (one in being with each other, also attacked (by Arius)), whether Gentile converts need to be circumcised, and so on.
Thank you for reading this post. I know that many of my family and friends who read this blog are Protestant, and I do not intend this as an attack on you personally but rather hope you read this and are challenged to learn and study the history of the canon of Scripture and to discern how and why you came to believe what you did about it.

I believe God had his hands on his Holy words down through the ages. What the Scholars miss is that God put within the book of Isaiah a MAP of the whole Bible, or what YOU call the cannon. The Catholic “church” was not around during Pentecost (a Jewish feast day in Acts 1) nor were they around during John’s writing of Revelation in 90 AD. The believers in Antioch where Paul’s journeys began from, and where the believers were first called “CHRISTIANS” not “Catholics” would have held on to copies of Paul’s writings. And the “cannon” of the Bible would have been compiled by them along with John’s help. The Catholic “church” had nothing to do with it. The Bible tells us what belongs. Isaiah 1:2 compared to Genesis 1:1; Isaiah 66:22 compared to Revelation 21:1; and finally Isaiah 40:3 compared to Matthew 3:3. The division is in the RIGHT PLACE with the beginning and end in the right place. As a Bible Believer, THIS is how I know 100% that I have the RIGHT BIBLE. Thank you for your time and attention.
Interesting! First of all though, careful with the theological terms! Evangelicalism, in its oldest incarnation, was/is a low church branch of the Church of England (hardly as you put it “radical reformation”). In modern American terms Evangelicalism emerged from the fundamentalist movement as a church for those interested in a more moderate, culturally engaged yet rigorous protestantism. Fundamentalism, in turn, was/is a movement driven by conservative Presbyterians (aka Reformed). More recently, evangelicalism as a term has been transformed into a socio-cultural catch all, without any particular theological implication. Anyways, as to the rest of this, I think you are missing the simple fact that Catholics and Protestants see the church and priesthood differently. We can agree that the church is authoritative, however for protestants it is made up entirely of priests, that is to say every faithful Christian is equally authoritative, not just popes, church fathers, etc. But in the end, we can agree that God miraculously has spoken to us at many times and in various ways and if we can accept that Word, we can be brothers in faith.