Some Protestants, like James White, will attempt to justify the doctrine of Sola Scriptura on the basis of the sufficiency of scripture, which they derive from 2 Timothy 3:16-17:All scripture is inspired by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work.Indeed, one can watch many presentations where James White painstakingly attempts to derive Sola Scriptura as an implication of 2 Tim. 3:1617, demonstrating that it is, at best, an implicit biblical teaching.Sufficient is not explicitly said of Scripture in 2 Tim. 3:1617 or anywhere else in the biblical canon. St. Pauls point seems to be that the man of God may be complete, equipped for every good work, which may imply that several other conditions obtain with respect to the man of God, e.g., that the man is baptized, participating in the sacramental life of the Church, submitting himself to his bishop, etc. In other words, St. Paul is saying that Scripture is profitable for the man of God, and it is strictly a Reformed interpretation that holds Scripture alone is what completes this man. Is Scripture sufficient to make one a man of God? The verse doesnt say that. I would suggest that the man of God needs grace, and Scripture is not identical to grace. But let us set aside this objection and consider, for a moment, the possibility that 2 Tim. 3:1617 implicitly teaches Sola Scriptura. Undoubtedly, if this were so, Sola Scriptura would be an essential, though implicit, biblical doctrine. And thats a problem. As we have seen, it depends on fallible suppositions about the man of God and interpretations of the language of the textinterpretations about which White and others could be wrong, as they are admittedly not infallible in their exegesis.Consider other implicit biblical doctrines that most Christians would consider absolutely essential to the faith, whether they pertain to the Trinity, Christology, soteriology, sacramentalism, or ecclesiology. Insofar as they are implicit, they hinge on fallible interpretations of Scripture. For the Protestant, this is undeniable unless they admit a secondary rule of faith aside from the Bible by which implicit teachings are derived. They might argue that Scripture interprets Scripture, but this really wont do, since it is precisely which Scriptures to apply and how they are applied that is subject to error. Moreover, it is evident that implicit biblical doctrines are not simply derived by applying one Scripture to another. Grammatical, historical, and theological considerations are major factors. So, there is still a problem, which I think can be logically drawn out. In what follows, I hope to formally demonstrate this.LexiconWe define the following predicates and propositions:Ix x is an implicit Biblical doctrineEx x is an essential Biblical doctrineFx x is fallibly derived through exegesisS Sola Scriptura is trueC Scripture alone is sufficient to derive all essential Biblical doctrinesArgumentS C (premise)C (x)(Ex Fx) (premise)(x)(Ix Fx) (premise)(x)(Ix Ex) (premise)S (x)(Ex Fx) (1,2 HS)I E (4 EI)I (6 Simp) I F (3 UI)F (7,8 MP)E (6 Simp)F E (9,10 Conj)(x)(Ex Fx) (11 EG)(x)(Ex Fx) (12 DN)(x)(Ex Fx) (13 QN)(x)(Ex Fx) (14 DM)(x)(Ex Fx) (15 Impl)S (5,16 MT)Q.E.D.Theological and Philosophical ImplicationsEssential Implicit Biblical Doctrines are incompatible with the Sufficiency of Scripture, refuting Sola Scriptura:If Scripture is sufficient, then the essential doctrines of Scripture must be infallible.But many essential doctrines are only implicitly found in Scripture, making their derivation fallible.And if many essential doctrines are fallible, then Scripture is insufficient.The Catholic Framework Avoids This Problem:Catholics assert the infallibility of the Magisterium, which allows implicit doctrines to be infallibly established.This resolves the tension that arises from essential doctrines being implicitly found in Scripture, as such doctrines can be dogmatically defined via the Magisterium.This accords with Dei Verbum, which teaches: Sacred Scripture and the teaching authority of the Church, in accord with Gods most wise design, are so linked and joined together that one cannot stand without the others, and that all together and each in its own way under the action of the one Holy Spirit contribute effectively to the salvation of souls (DV II.10).