What good are prophets if they're not infallible? This is a question I have been asked many times, and a variant of this question has come up on Times & Seasons.
Nate has challenged John H.: “The trick is to come up with some theory that doesn’t reduce the prophets to well meaning old men; some theory that still concedes to them some meaningful special access to the divine.” And his definition of “meaningful special access” of prophetic authority has these three points: “(1) we are given substantive counsel; (2) that we should follow; (3) that differs from our own substantive views.”
It seems to me that such a model is actually quite simple, though I'm not sure “special access to the divine” is quite the right phrase. I'd like to lay out some groundwork underlying my model, then propose my model of prophetic authority.
The prophets are the only ones who can receive revelation for the whole Church. While (as in an example given in the comments on the T&S thread) Church members can receive exactly the same revelations, their revelations are not for the Church as a whole. Perhaps we can call this “revelatory scope.” This is strongly emphasized by the Brethren, and, as far as I can tell, it is the only difference between revelations of prophets, seers, and revelators and the general membership of the Church. Many prophets (especially President Hinckley) have taught that they receive revelation in the same way the rest of us do, and that even the rarer, more unusual manifestations are available to every one of us as we are prepared to receive them.
This brings up the question of preparation. It seems to me that we tend to describe the men called as prophets, seers, and revelators as especially righteous. While it is likely generally the case that these men are very righteous, I'm not sure that we can say that they are necessarily the most prepared of anyone in the Church to receive revelation. There may very well be many other people in the Church who are better prepared to receive revelation, but may not have the other qualities that led to the calling of the Brethren to their positions. But it does seem that, for the most part, the Brethren must have a minimum of preparation to receive divine guidance for their duties. Someone unprepared to receive revelation is not a likely candidate for such a high position of responsibility. (That said, it seems probable that some of them may struggle with this more than others. For example, see some of the accounts of Heber J. Grant's call to become a stake president and, later, an apostle.)
From the foregoing, then, it seems that we have a couple of items: 1. The revelatory scope of prophets, seers, and revelators is greater than that of the general membership. 2. Prophets, seers, and revelators are generally very righteous men, who qualify to receive revelation. This does not make them infallible, however. In fact, they have specifically denied any claim of infallibility.
A third item (in connection with revelatory scope) is that the pronouncements of unified prophets, seers, and revelators can be binding on the Church. Whether something is binding on the Church is not the same thing as whether it is correct, however. A binding pronouncement is one that, if violated, results in consequences such as loss of a temple recommend or excommunication from the Church. For example: the Word of Wisdom (including a prohibition on wine) is binding on the Church, even though the Lord drank wine and has stated his intention to do so again with his prophets. The rule is binding on the Church, even if it may not be correct in all its particulars.
I recognize that my example above is one of practice, rather than doctrine. However, the decanonization of the Lectures on Faith seems to indicate that the same principle applies to doctrinally binding statements. The Lectures on Faith, as part of the Doctrine & Covenants, were doctrinally binding on the Church, as are all the standard works. And our acknowledgment of possible errors in the Bible and the Book of Mormon does not prevent those from being doctrinally binding on the Church.
Given this groundwork, I would propose the following model of prophetic authority:
Sometimes the prophets receive true revelation that I should follow that differs from my substantive views: I am not infallible. And sometimes I receive true revelation that leads me to differ with the substantive views of the prophets: they are not infallible.
Messy, huh? Yes, but the order comes in the authority: in what is applicable to and binding on the Church as a whole. What this means, unfortunately, is that sometimes we have to make hard decisions: are we confident enough in our own revelation (and is it substantive enough) to continue to differ with the prophets, seers, and revelators, or do we defer to their authority because we value order? We are just as fallible as they are.
What good are prophets if they're not infallible? I would reply with similar questions: What good are teachers if they're not infallible? What good is peer review in the academic world if it is not infallible? What good are the scriptures if they're not infallible? Here's the good: They challenge us; they teach us; they remind us; they prompt us to seek further, not to be satisfied with where we are; they prod us Godward.
And they do this for the community as a whole, which is a value in itself. Mormonism is strongly focused on community. We are not, despite the high value we place on agency, a religion that is all about our individual relationship with God. Mormonism is a religion that is all about our communal relationship with God and each other. That is why questions are raised about the "Mormonness" of someone who questions the prophets -- because we place a very high emphasis on community.
The trick, as Nate might put it, is in finding the balance between the community and the individual, between prophetic authority and personal revelation, between continuity of doctrine and continuing revelation.