In a Roman Catholic book on John Calvin comes the following quotation from John Calvin:
Every child knows that in the writings of the apostles, which these men represent as mutilated and incomplete, is contained the result of that revelation which the Lord then promised to them. (IV, 8:14)Roman Catholic Analysis
Catholics do not do this. Scripture often points to traditions outside of itself that are true. Therefore, to hold such a view is not to hold to a "mutilated and incomplete" Bible. It is to hold to all that the Bible itself asserts. The one who denies that there is such a thing as a tradition described and fully accepted in Scripture, is selectively disbelieving part of that same Scripture. It isn’t being accepted in its totality.Context
Calvin is discussing the claim that extra apostolic God-breathed material exists beyond the Bible. He argues in response that when the apostles committed their doctrine to writing, they weren't so incompetent to leave important things out which needed to be given to the church via a "living voice." Quoting Augustine, Calvin says, "When the Lord said nothing, who of us may say,'These things are or those things are’? Or if one dare say so, what proof does he provide”?
Here would have been a perfect spot for the author to actually supply a Biblical Catholic answer. Which God breathed Traditions does the Bible say exist outside of its pages? Well, of course the Bible can't tell you what they are, that's why they're Traditions! Who can tell you? Why, the Roman Catholic Church... but can they really? They've yet to declare whether the partim-partim or material view is that described in Trent. Those Calvin faced were clearly of the partim-partim camp.
Catholic Partim-Partim Sufficiency claims part of God’s special revelation is contained in the Scripture, and part is contained in Tradition. In this view, the Bible is “materially insufficient.” The New Catholic Encyclopedia states of those who hold this view, “Neither tradition nor Scripture contains the whole apostolic tradition. Scripture is materially (i.e., in content) insufficient, requiring oral tradition as a complement to be true to the whole divine revelation” [Source: New Catholic Encyclopedia (1967) Vol 14, p.228].
The other is the Roman Catholic Material Sufficiency view. It holds the Scriptures are “materially sufficient” meaning the entire content of revelation is in the Scriptures, or that divine revelation is contained entirely in Scripture. That is, all the doctrines Christians are to believe are found in the Bible. Along with affirming totum in Scriptura, Catholics who maintain material sufficiency also hold “Tradition” likewise contains the entire content of revelation: “totum in traditione”. Thus, two vehicles carry God’s special revelation in total: Scripture and Tradition. Both are infallible in the Catholic view.
A search of the author's blog for the term "Partim Partim" provided two hits, and neither were his words. He does though appear to be holding to the material view:
We believe Scripture is materially sufficient, but not formally sufficient without the Church as a Guide. We believe that Scripture and Tradition are "twin fonts of the same divine wellspring," as Vatican II states.Calvin was well within his right to criticize the view of his contemporaries. They indeed held that the Bible was not complete and needed to have things added.