The word inerrant means that something, usually a text, is “without error.” The word infallible—in its lexical meaning, though not necessarily in theological discussions due to Rogers and McKim—is technically a stronger word, meaning that the text is not only “without error” but “incapable of error.” The historic Christian teaching is that the Bible is both inerrant and infallible. It is without error (inerrant) because it is impossible for it to have errors (infallible).

In his chapter on “The Inerrancy of Scripture” in The Doctrine of the Word of God (Phillipsburg, NJ: P&R, 2010), John Frame offers some important distinctions and clarifications on the doctrine. He points out that inerrancy suggests to many the idea of precision, rather than its lexical meaning of mere truth.

Frame points out that “precision” and “truth” overlap in meaning but are not synonymous:

A certain amount of precision is often required for truth, but that amount varies from one context to another. In mathematics and science, truth often requires considerable precision. If a student says that 6+5=10, he has not told the truth. He has committed an error. If a scientist makes a measurement varying by .0004 cm of an actual length, he may describe that as an “error,” as in the phrase “margin of error.”

Frame then reminds us that truth and precision are usually more distinct when we move outside the fields of mathematics and science:

If you ask someone’s age, the person’s conventional response (at least if the questioner is entitled to such information!) is to tell how old he was on his most recent birthday. But this is, of course, imprecise. It would be more precise to tell one’s age down to the day, hour, minute, and second. However, would that convey more truth? And, if one fails to give that much precision, has he made an error? I think not, as we use the terms truth and error in ordinary language. If someone seeks to tell his age down to the second, we usually say that he has told us more than we want to know. The question, “What is your age?” does not demand that level of precision. Indeed, when someone gives excess information in an attempt to be more precise, he actually frustrates the process of communication, hindering rather than communicating truth. He buries his real age under a torrent of irrelevant words. Similarly, when I stand before a class and a student asks me how large the textbook is. Say that I reply “400 pages,” but the actual length is 398. Have I committed an error, or told the truth? I think the latter, for the following reasons: (a) In context, nobody expects more precision than I gave in my answer. I met all the legitimate demands of the questioner. (b) “400,” in this example, actually conveyed more truth than “398” would have. “398” most likely would have left the student with the impression of some number around 300, but “400” presented the size of the book more accurately.

The relationship between “precision” and “error,” Frame says, is actually more complicated than many recognize. “What is an error?” sounds like a simple question with an easy-to-find answer. But “identifying an error requires some understanding of the linguistic context, and that in turn requires an understanding of the cultural context.”

A child who says in his math class that 6+5=10 may not expect the same tolerance as a person who gives a rough estimate of his age or a professor who exaggerates the size of a book by two pages. We should always remember that Scripture is, for the most part, ordinary language rather than technical language. Certainly, it is not of the modern scientific genre. In Scripture, God intends to speak to everybody. To do that most efficiently, he (through the human writers) engages in all the shortcuts that we commonly use among ourselves to facilitate conversation: imprecisions, metaphors, hyperbole, parables, etc. Not all of these convey literal truth, or truth with a precision expected in specialized contexts; but they all convey truth, and in the Bible there is no reason to charge them with error.

How then does inerrancy relate to precision? Frame suggests “sufficient precision” as opposed to “maximal precision.”

Inerrancy, therefore, means that the Bible is true, not that it is maximally precise. To the extent that precision is necessary for truth, the Bible is sufficiently precise. But it does not always have the amount of precision that some readers demand of it. It has a level of precision sufficient for its own purposes, not for the purposes for which some readers might employ it.

Frame then introduces an important aspect of propositional language: it “makes claims on its hearers”:

When I say that the book is on the table, I am claiming that in fact the book is there. If you look, you will find it, precisely there. But if I say that I am age 24 (do I wish!), I am not claiming that I am precisely 24. I am claiming, rather, that I became 24 on my last birthday. Moreover, if I say, as in the previous example, that there are 400 pages in a textbook, I am not claiming that there is precisely that number of pages, only that the number 400 gives a pretty reliable estimate of the size of the book. Of course, if I worked for a publisher, and gave him an estimate of the size of the book that was two pages off, I could cost him a lot of money and myself a job. In that context, my imprecision would certainly be called an error. However, in the illustration of the professor making an estimate before his class, it would have been inappropriate to say that he was in error. Even though I use the same language in the two situations, I am making a different claim in the first situation from the claim I make in the second. Therefore, the amount of precision demanded and expected in one case is different from what is demanded and expected in the other. In the one case, I have made an error; in the other case not.

Frame points out that a “claim” in this sense can be explicit or implicit.

If someone asks me to quote a Bible passage, and I say “this is inexact,” I am making an explicit claim, namely, “I will give you the gist of it, but not the exact words.” Nevertheless, it is rare in language for someone to make his claims explicit in that way. When a person gives his age, he rarely says, “I am giving you an approximate figure.” Rather, he simply accepts the custom of approximating one’s age by the last birthday, assuming that people will understand that custom and will not be misled into thinking that his answer is absolutely precise. In following this custom, people understand that he is making an implicit claim.

Frame applies this principle to the biblical language and world:

So, in reading the Bible, it is important to know enough about the language and culture of the people to know what claims the original characters and writers were likely making. When Jesus tells parables, he does not always say explicitly that his words are parabolic. But his audience understood what he was doing, and we should as well. A parable does not claim historical accuracy, but it claims to set forth a significant truth by means of a likely nonhistorical narrative.

This leads to Frame’s definition of inerrancy: