If there is a hub around which LDS epistemology revolves, surely it is to be found in Moroni’s Promise:
Moroni 10:3-5:
3 Behold, I would exhort you that when ye shall
read these things, if it be wisdom in God that ye should read them, that ye
would remember how merciful the Lord hath been unto the children of men, from
the creation of Adam even down until the time that ye shall receive these
things, and ponder it in your hearts.
4 And when ye shall receive these things, I would
exhort you that ye would ask God, the Eternal Father, in the name of Christ, if
these things are not true; and if ye shall ask with a sincere heart, with real
intent, having faith in Christ, he will manifest the truth of it unto you, by
the power of the Holy Ghost.
5 And by the power of the Holy Ghost ye may know
the truth of all things.