The Shifting Definition of Sola Scriptura

Sola scriptura is Latin for “by Scripture alone,” and it’s one of the key slogans of the Protestant Reformation. 

I often explain it by saying that it’s the idea we need to produce Christian doctrine “by Scripture alone,” meaning—among other things—that every Christian doctrine must be explicitly or implicitly contained in the Bible. 

This is how I understood it as an Evangelical, and this understanding seems confirmed by experience, as Catholics are regularly confronted by Protestant Christians with the question, “Where is that in the Bible?”—a demand to produce Scripture verses as proof of some particular Catholic belief or practice. 

In recent decades, a common response by Catholic apologists is to turn this question around and say, “Where is sola scriptura in the Bible?” The point is, if every doctrine must be provable from the Bible, then sola scriptura also must be provable. If it isn’t, then it’s a self-refuting doctrine. 

How can Protestants respond to this challenge? One approach is to point to verses that a Protestant thinks prove sola scriptura, but this has not been successful. There are no verses that state the doctrine outright, and the arguments by implication are weak and unpersuasive. 

Another approach that I’ve encountered in recent years involves what seems to be a redefinition of sola scriptura.  

For example, Protestant apologist James White writes, “Sola scriptura literally means ‘Scripture alone.’ Unfortunately, this phrase tends to be taken in the vein of ‘Scripture in isolation, Scripture outside of the rest of God’s work in the church.’ That is not its intended meaning; again, it means ‘Scripture alone as the sole infallible rule of faith for the church.’” 

The key part of that is the last bit: the idea that sola scriptura means that Scripture is the only infallible rule of faith. 

This is a narrower understanding of the doctrine than the common one, and I’ve seen it suggested that this is the historic Protestant understanding, based on appeals to Protestant confessional documents like the 1647 Westminster Confession of Faith and the 1689 London Baptist Confession of Faith—both of which use exactly the same language in key passages to articulate their teaching on Scripture. 

It’s easy to see why the narrower definition would be attractive. The less that is claimed for sola scriptura, the smaller an apologetic target it presents, and the easier it would be to defend. 

I’ve even seen it suggested (not by White, but by others) that when it is understood in this narrow sense, sola scriptura does not need to be taught in Scripture. 

And that creates a rhetorically attractive situation for a Protestant apologist. Instead of needing to produce verses of Scripture that state or imply sola scriptura, he can simply say, “Name another infallible rule of faith,” thus putting the burden of proof back on a Catholic. 

A Protestant apologist can even concede that perhaps in the Apostolic Age, there was an additional infallible rule of faith in the form of apostolic Tradition, but he can assert that we don’t have that today. Scripture is all we’ve got that’s infallible. 

Despite its attractiveness to Protestants, there are several problems with this approach. 

The first problem is that, even if we grant this understanding of sola scriptura, the argument is answerable. 

A “rule of faith” is something that is authoritative for faith, and we have two infallible authorities for the Faith in addition to Scripture. Apostolic Tradition is an infallible source of information regarding it, and the Magisterium is an infallible interpretive authority. 

A Protestant may not be convinced that we have these two authorities or that they are infallible, but it is nonetheless true, and so a Catholic can meet the challenge of naming additional infallible rules of faith. 

Unfortunately, if he takes this approach, the discussion is likely to degenerate into quibbling about the accuracy of particular Traditions or magisterial acts, so it’s better to take a different approach, however sound this one is in principle. 

A second problem with the reduced definition is that it doesn’t seem to accurately reflect the historic Protestant view. 

Not only does it not reflect the way sola scriptura is used in practice today, but it also does not reflect what is written in historical explanations such as those found in the Westminster Confession and the London Baptist Confession. 

It is true that the London Baptist Confession says that “the Holy Scripture is the only sufficient, certain, and infallible rule of all saving knowledge, faith, and obedience” (1:1).  

This uses the words only, infallible, rule, of, and faith, but it also uses other words, and one is particularly important: sufficient. 

Sufficient for what? The answer provided in this passage is that Scripture is sufficient for “knowledge, faith, and obedience,” but this is not to be understood too expansively. Nobody thinks that Scripture is sufficient to give you knowledge of geometry or engineering or medicine.  

The knowledge in question is what is required for Christian doctrine concerning faith and morals. This is reflected later in the London Baptist Confession, where it states that “the whole counsel of God concerning . . . faith and life is either expressly set down or necessarily contained in the Holy Scripture” (1:6).  

The same is indicated in the Westminster Confession with almost identical phrasing, although the latter is more explicit, saying that the whole of God’s counsel regarding faith and life “is either expressly set down in Scripture or by good and necessary consequence may be deduced from Scripture” (1:6). 

“The whole counsel of God” means everything that God has told (counseled) us—everything he wants us to know about “faith and life,” or “faith and morals,” to put it in more Catholic terms. 

So we find that, in their teaching on Scripture, these confessions assert more than that the Bible is the only infallible authority for Christian faith. They also say that it is sufficient in that it contains—either expressly or by implication—everything God has revealed to us concerning doctrine on faith and morals. 

This raises serious questions about whether it’s accurate to characterize the historic Protestant understanding of sola scriptura as being limited to the idea that Scripture is our sole infallible rule of faith. It appears that the historic sources indicate that it’s a sufficient rule for Christian doctrine. 

A third problem I’ve noticed about the restricted definition of sola scriptura is that it isn’t used consistently. 

In his book Scripture Alone, after offering the narrow definition of the term, White goes on to say that “the corollary of sola scriptura is that all a person must believe to be a follower of Christ is found in Scripture and in no other source” (his emphasis). 

That’s a clear statement of the sufficiency of Scripture, and here White presents it as a corollary of sola scriptura, though it’s not—at least under the dictionary definitions of a corollary as “a proposition inferred immediately from a proved proposition with little or no additional proof” or “something that naturally follows.” 

Even if Scripture were our sole infallible source of authoritative information about the Faith, that doesn’t require it to contain everything God wants us to know.  

It would be possible for God to give us other authoritative, accurate information about doctrines he wants us to know and believe, even if this information is not contained in an infallible collection such as Scripture. 

What’s significant is that, instead of simply defending sola scriptura on its own, White feels the need to link it to the doctrine of Scripture’s sufficiency. 

The reason for that is clear: Scripture’s sufficiency is important for Protestant theology. Among other things, you wouldn’t be able to ask questions like “Where’s that in the Bible?” as a demand for scriptural proof of a doctrine if there were no claim that Scripture states or implies all of Christian doctrine. 

Whereas White seems to keep sola scriptura and the sufficiency of Scripture distinct here, other authors are not as particular. 

My observation has been that when they are on the defensive in a discussion—when scriptural proof is asked for sola scriptura—Protestants use the narrow definition.  

But in other circumstances—when they are on the offensive and questioning Catholics about some matter—they use sola scriptura more expansively, as if it includes the idea of sufficiency. 

It’s as if the understanding they have of sola scriptura shifts depending on the context, and it’s fair to point this out in a discussion and ask for an explanation. 

This brings us to a fourth problem with the narrow definition: it doesn’t really matter whether a person uses it consistently or not if he also believes in the sufficiency of Scripture. 

I could imagine a Protestant saying, “When I refer to sola scriptura, all I ever mean by the term is that Scripture is our sole infallible rule of faith. That doesn’t stop me from also appealing to the sufficiency of Scripture to grill you about your Catholic beliefs.” 

And that’s fine. I would challenge the idea that other Protestants commonly understand sola scriptura as narrowly as he does, but that doesn’t prevent him from using the term in an idiosyncratic fashion. As Humpty Dumpty says in Through the Looking Glass, “when I use a word, it means just what I choose it to mean—neither more nor less.”  

In philosophy, that’s known as a stipulative definition—a meaning that you stipulate a term to have, whether other people use it that way or not. And that can be okay as long as you realize that’s what’s happening. 

But it won’t save sola scriptura. 

If you restrict the definition of sola scriptura to the claim that Scripture is our only infallible rule of faith, and if you believe in the sufficiency of Scripture, then you’re still going to need to be able to prove sola scriptura from Scripture alone. 

You’re going to need to find the idea that the Bible is our only infallible rule of faith, as the London Baptist Confession put it, “expressly set down or necessarily contained” in Scripture.  

Or you’ll need to be able to show that this claim “is either expressly set down in Scripture or by good and necessary consequence may be deduced from Scripture,” as the Westminster Confession puts it. 

How on earth can you do that? There are no passages in the Bible that expressly say, “The Bible is our only infallible rule of faith.” Neither are there passages that allow you to deduce this so that it is “necessarily contained” in Scripture. 

Indeed, the argument that is usually envisioned is historical rather than scriptural, with Protestants seeking to poke holes in various post-biblical Patristic and magisterial texts in an effort to show that only Scripture must be infallible. 

But that won’t do if Scripture is sufficient. You’re going to need to find verses that state or imply that Scripture is the only infallible source for Christians—at least in the post-Apostolic Age. 

The problem is actually worse, because you’ll also need to find verses that state or imply that Scripture is sufficient—that it contains all doctrine regarding faith and morals.  

There is simply no way to do this. Not only are there no verses that say this outright, but no verses even imply it. 

Putting yourself in the position of a first-century Christian will make this clear. In the first century, much of Christian doctrine was passed on in the form of oral tradition rather than Scripture (1 Cor. 11:2; 2 Thess. 2:15, 3:6), for the simple reason that much of it had not yet been written down. 

But to show that Scripture is sufficient today, you’ll need to find passages that say or imply that all such doctrinal traditions will be written down by the end of the Apostolic Age or that they will lose their authority after the Apostolic Age, leaving Scripture as sufficient for Christian doctrine today. 

There are no passages that say or imply anything close to this. Indeed, the New Testament authors tended to assume that they would be alive at the Second Coming (“we who are alive, who are left”—1 Thess. 4:17), meaning that they weren’t envisioning a post-Apostolic Age. 

Eventually, Paul and Peter became aware that they would die (2 Tim. 4:6-8, 2 Pet. 1:14-15), but that didn’t mean all the apostles would be dead by the time Jesus came back. 

The only passage in the New Testament that unambiguously envisions a long period of time before the end is John’s discussion of the millennium (Rev. 20:1-10), and this passage says nothing about all apostolic Traditions eventually being written in Scripture or anything about them losing their authority.  

As a result, the doctrine of scriptural sufficiency refutes itself. Scripture is not sufficient to teach its own sufficiency. 

So, whether the doctrine of sufficiency is included in the definition of sola scriptura or not, the doctrine falls. Sufficiency means that Scripture must teach both that Scripture is our only infallible rule of faith and that it is sufficient for Christian doctrine. 

It teaches neither, so both are refuted.