Anyone who is interested in the evolution of the LDS temple cultus must read this thesis. In that regard alone it is extremely valuable.
Ehat's argument is basically this: In 1842 and 1843, Joseph Smith unfolded the full temple cultus, which apexed in the "fullness of the priesthood," which was the second anointing, through which a person's calling and election was made sure. He revealed all of these things to an esoteric inner church, which started with a group of nine, but eventually expanded to a group of ca. 75 people. This group, often simply called "The Quorum" became the new Church elite, because these people were the ones who possessed the fullness of the priesthood or access to it. As the capstone of Smith's vision, the fullness was considered absolutely vital to the salvation of the saints.
The Quorum did not map well onto the old organizational structure of the LDS Church. This was priesthood that did not integrate logically into the old designations of Aaronic and Melchizedek, or the organization of councils and quorums. In a sense, it replaced all of these things by packing them into the temple cultus. The endowment/second anointing contained a fullness of all three priesthoods: Aaronic, Patriarchal, and Melchizedek, with the fullness of the Melchizedek being the assurance of exaltation.
The crucial defection of William Law over polygamy came when he was a member of The Quorum, but had not been sealed nor received his second anointing. He was essentially refused the fullness because he rejected polygamy. Then Law set about taking down Joseph Smith over polygamy. In the opposition to polygamy, he was joined by William Marks, though William did not pursue the Laws' concerted effort to take down Joseph through exposé and legal means. So, the break occurred within The Quorum itself, on the question of polygamy.
A pivotal event in the process freed Joseph to pursue revealing the fullness of the priesthood: the conversion of his brother Hyrum to polygamy. Once Hyrum was convinced that polygamy was divinely mandated, he embraced it fully, and Joseph felt free to move forward revealing the fullness. But, something else interesting happened. Because of his earlier appointment as Church Patriarch and co-prophet, Hyrum felt free to perform sealings without Joseph's knowledge or approval. He just assumed this was OK.
When Joseph found out, he panicked a bit. Polygamy was such a hot potato that it would be disastrous to have multiple people going around performing polygamous sealings. One might also see this as Joseph Smith being a stickler about the divine order of things as he truly believed it. He put a stop to Hyrum's unauthorized sealings and fixed that situation. D&C 132 contains a key passage that shows how Smith conveyed his unique authority through revelation. It builds on the earlier language of Section 43:
132:7 wrote:And verily I say unto you, that the conditions of this law are these: All covenants, contracts, bonds, obligations, oaths, vows, performances, connections, associations, or expectations, that are not made and entered into and sealed by the Holy Spirit of promise, of him who is anointed, both as well for time and for all eternity, and that too most holy, by revelation and commandment through the medium of mine anointed, whom I have appointed on the earth to hold this power (and I have appointed unto my servant Joseph to hold this power in the last days, and there is never but one on the earth at a time on whom this power and the keys of this priesthood are conferred), are of no efficacy, virtue, or force in and after the resurrection from the dead; for all contracts that are not made unto this end have an end when men are dead.
So, here is the problem. Again Joseph Smith has shown us very clearly what he viewed to be, or at least communicated to be, God's order for handling the highest responsibilities and blessings in the Church. God authorizes one person at a time, and only one person, to exercise these keys. Better yet, he only confers those keys on one person. Nothing here indicates that everyone who received the fullness had equal access to them and could confer them on others, even Hyrum who was appointed Patriarch, Prophet, and Joseph's successor.
The language used in the second anointing reflected these differences. One could be anointed a king and priest "in" Israel, which meant that you had exaltation but you did not have ecclesiastical authority, a king and priest "in and over" Israel, which meant that you had exaltation and subordinate authority, or a king and priest "over" Israel, which meant that you were Joseph Smith, Jr., the one man upon whom all the keys were conferred and the only one authorized to confer the fullness of the priesthood on others. Everyone whose calling and election was made sure received that fullness at Joseph Smith's direction.
Joseph Smith at one point delegated to Brigham Young the authority to confer the fullness of the priesthood on the Q12. This meant that Joseph exercised his keys through Brigham to confer the fullness of the priesthood on the rest of the Q12. By the time of Smith's assassination, it is likely that all of the apostles in the Q12 had received the fullness of the priesthood.
So, if you consider this situation as Brigham Young, now that anyone who was an adult and had a credible claim to be the appointed successor of Joseph Smith is dead, you might be thinking that Joseph had delegated the ability to confer the fullness of the priesthood to others, so you have better standing than most anyone to lead the LDS Church. However, you were not appointed as the scriptures dictated, so you can't come out and falsely make such a claim. Instead, you have to lay the groundwork and build the consensus that would allow you to do this.
I can understand Brigham Young's reasoning. The problem is that it really doesn't work. It had to work. They made it work. But, it wasn't strictly kosher. And Willard Richards' and Brigham's actions do raise questions.
Newel K. Whitney, the Presiding Bishop and a member of the Quorum, said that Samuel H. Smith was appointed Joseph's successor in the case of Joseph's and Hyrum's deaths. Samuel was a member of The Quorum. The problem is that Samuel seems not to have received the fullness of the priesthood, and he died before the Twelve returned. So, even if he had been appointed Smith's successor, he could only receive the fullness from the one with the keys. Joseph Smith III was also appointed as an eventual successor, but presumably he would have received the fullness of the priesthood before he became the one man with the keys.
But there is an even bigger problem. Joseph Smith never appointed Brigham Young or the Twelve to be his successors. This is probably the reason why, at the time, they only thought in terms of a guardianship. The discussion of a guardianship is best explained by the common understanding among members of the Quorum that Joseph Smith arranged it so that only one person held the keys, and that the successor had to be appointed by the person holding the keys.
Let's imagine that Samuel had lived. I don't think we need to question whether he had been appointed successor. Newel K. Whitney attested to it, and Lucy Mack Smith felt that Samuel was to be the successor. The evidence of his place in the succession is pretty damn good. It was not simply a matter of Samuel making an empty claim because he was feeling entitled. If all had worked in accordance to the system Joseph set up, then Samuel would have had to receive the fullness of the priesthood before he could step into his role as president.
Who could he get the fullness from? Who could anyone get the fullness from? The guy who held the keys was dead. Only Brigham had any kind of argument that he had been delegated to perform the second anointing on Joseph Smtih's behalf. But he had been delegated that authority to pass the second anointing on to members of the Twelve, not just anybody. Samuel wasn't in the Q12.
But the same problem that confronted Samuel applied to everyone. There was no one who 1) was appointed successor by Joseph Smith, and 2) received a fullness of the priesthood. You are at a complete impasse, unless you argue that Joseph Smtih in the post-mortal realm was still wielding and exercising the keys, and others were only exercising them through his otherworldly authority.
I still tend to think that Samuel Smith had the best argument for being Joseph Smith's successor, much better than Brigham's. And I suspect that he was murdered in order to remove him from consideration. I find Willard Richards' participation in events suspicious. And, most importantly, I do believe that Joseph's and Hyrum's death did create a kind of impasse in the continuation of Church leadership. Only one man, appointed by the one man, could hold the keys and exercise them. The Twelve was not in a position to do so. And it really was not the pattern in Mormon priesthood for a Quorum to take over by common consent.
The argument from common consent really doesn't work. And I don't believe that the people making the argument truly believe it themselves, if they have any idea of what they are talking about. I think the truth of the matter is that, as Brigham Young himself pointed out, Joseph Smith holds the keys to this dispensation in his exalted sphere. Those who exercise them to lead the LDS Church today really do so on the argument that it is ultimately Joseph Smith's authority that is being exercised through them. The pattern for doing this was established when Joseph told Brigham he could confer the fullness of the priesthood on other members of the Twelve. That is the pattern of delegation; the only difference now is that the delegation has to take place from Joseph's perch in the Celestial Kingdom. "Mingling with gods, he can plan for his brethren."
Why don't they just come out and say this? First, I believe that the PR of saying your Church runs on authority from a divinized Joseph Smith would be disastrous. Joseph Smith's theological significance is a very tricky subject, since the LDS Church contends that Smith is not worshiped. Second, I think it is because the secrecy that surrounds the temple and, even more so, the second anointing is so thick that it is difficult to use that in a way that avoids other uncomfortable questions. But, I think the answers are actually fairly simple, once you understand the fullness of the priesthood as something concrete and its role in the succession. I suspected that the Quorum and membership in it played a role in these events. But I really had no idea how pivotal its role was until I started to read Ehat's thesis.
Now, I have to say here that Ehat's thesis is pretty old (1982, so pre-Quinn's Origins), and I tend to think he is relying on some sources that have probably been picked apart by Mormon historians way above my paygrade (I am a mere enthusiast when it comes to Mormon history). So, in truth I don't know how well Ehat's thesis continues to hold up. I think that, overall, a lot of what he is saying is sound, but I do run across individual sources he is using and think that there very well could be post hoc editing that he is not acknowledging. I would like to know what the real experts have to say about it.