Strange that he felt a need to defend an idea that, as far as I remember, is not part of official mormon doctrine.Ah, yes, OMD.
But why isn't it official? How many Latter-day Saints (and what kinds) need to believe it before it becomes official? Is there a list? Determining official Mormon doctrine is harder than it ought to be.
Usually religions make statements that can't really be confirmed or disconfirmed by empirical evidence, like 'God exists' or 'After you die, you continue to live on as a spirit'. But occasionally a religion will make a claim that can be tested and disconfirmed. For example, physical evidence indicates that the earth came together right where it is, instead of being smooshed together. People with dark skin who join the Church do not become whiter, contre the Book of Mormon and General Conference.
What's a true believer to do? Easy. Just say that the claim was never 'true church doctrine' in the first place. This is possible because of the LDS concept of 'continuing revelation': that later statements by church leaders trump older ones. So old doctrines can be dropped without much trouble; they've been superceded by new knowledge. This is why people in the know no longer teach that the whole of North and South America was populated by Hebrews, and they now say that the entire Book of Mormon narrative took place within a few square blocks in Guatemala.
'Official Church Doctrine' (which I'll hereafter call 'OCD') is a slippery notion. There's an incredibly high bar for a doctrine to be considered 'official', and even statements that meet the criteria for OCD can be disavowed if the belief becomes problematic.
An idea can be taught by Joseph Smith or Brigham Young, spoken from the pulpit of General Conference, written in Church publications, be widely believed by the membership and still be disqualified from OCD status if the need arises.
So what is OCD? The Doctrine and Covenants says that anything that missionaries say when they are "moved upon by the Holy Ghost" is scripture. Since there's no way to tell when someone's been 'moved upon' in this way, we need another definition.
Here's a page that addresses this question:
Virtually every religion has procedures for distinguishing the individual beliefs of its members from the official doctrines of the church, and so do the Latter-day Saints. In fact among the Mormons the procedure is remarkably similar to that of many Protestant denominations. An example of the procedure can be taken from the records of the Fiftieth Semiannual General Conference of the LDS church, 10 October 1880, when President George Q. Cannon addressed the conference:In other words, OCD is anything that isI hold in my hand the Book of Doctrine and Covenants, and also the book, The Pearl of Great Price, which books contain revelations of God. In Kirtland, the Doctrine and Covenants in its original form, as first printed, was submitted to the officers of the Church and the members of the Church to vote upon. As there have been additions made to it by the publishing of revelations which were not contained in the original edition, it has been deemed wise to submit these books with their contents to the conference, to see whether the conference will vote to accept the books and their contents as from God, and binding upon us as a people and as a Church.Subsequent changes of content in the standard works of the Church have been presented similarly to the membership in general conference to receive a sustaining vote. It is that sustaining vote, by the individual members or by their representatives, that makes the changes officially binding upon the membership as the doctrine of the Church.
a) in the Standard Works, and
b) sustained by the membership.
In fact, this definition of OCD is a bit of a furphy. There are wide swaths of doctrine that Latter-day Saints believe to be true that aren't in the Standard Works, including 'bones from other worlds', policies on illegal drugs, almost everything concerning temple work, and lots of ideas about the spirit world. There are also some ideas that are in the Standard Works, but that Mormons don't really practice, like Jesus' views on divorce, and meat in the Word of Wisdom.
This is not a bad thing — it's completely normal, as religions go — but it does mean that Mormon doctrine can metamorphose to protect itself. It makes it very hard to disconfirm an official doctrine, which is probably the point.
What I think is happening is something I call 'revelation by prevailing belief'.
1. Joseph Smith et al. started a lot of ideas during the early fertile part of church history. Some were based on made-up stories in the scriptures, and others they made up themselves (Book of Abraham, King Follett discourse).
2. These ideas go to work within the general membership, and at times compete in the minds of members. It's those memes again: the ideas are involved in an evolutionary struggle for mindspace, and some ideas will prevail. What gets taught in church and at conference are the beliefs that are winning. For example, the prohibition on R-rated movies was folklore when I was a lad, but in 1986, Benson mentioned it in conference, which was certainly enough to get that idea canonised.
3. If by some chance the belief becomes problematic, the Church's immune system kicks in. We start to hear some members claim that it's 'not church doctrine' in Sunday School or Elder's Quorum. This retroactive expungement will take a while to propagate through the community, just as the original doctrine did. It's hard to expel an entrenched doctrine though. It takes about 40 years, if ideas about Blacks and the pre-mortal life are any indication.
The difference, then, between true Mormon doctrine and Mormon folklore is that True Mormon doctrine is doctrine that is considered to be true by most Mormons at any given time. It's not pronouncements from General Conference that gives the official imprimatur — those statements are sometimes disavowed. It's not being published in the Standard Works — Latter-day Saints can ignore scriptures that don't coincide with prevailing belief. It's whether Mormons believe it enough not to challenge it in church.
This is why we see Mormon doctrine change subtly from generation to generation as unpalatable or scientifically bogus ideas are dropped. It's not just a Mormon thing; it happens in lots of religions these days (I'm thinking Vatican II). It's people making things up, and then adapting their beliefs when needed.
Personally, I don't mind if Mormon doctrine changes. There are quite a few beliefs that need to go. And even the scientific method allows for change. The difference is that when scientific ideas change, it's because new evidence (in the form of empirical observation) renders an old theory untenable. But when old Mormon beliefs get discarded, it's based on no evidence at all, or because Mormon doctrine needs to flee from scientific advancement.
However, as scientific knowledge expands and the God of the Gaps shrinks, I think there may come a time when overwhelming evidence may come head-to-head against a core Mormon belief, such that members won't be able to ignore it without disavowing the scientific method entirely. That will be interesting.