The Church of Jesus Christ of Latter Day Saints is the organization.
Mormonism is the movemement.
I don't usually get involved in terminology debates, but I think in this case I'm going to make an exception. How in the world did you come to the conclusion that Mormonism is a movement?
I looked up Mormonism
in Webster's New World College Dictionary
(published by MacMillan), and it defines the noun Mormon
as "a member of the Church of Jesus Christ of Latter-day Saints (commonly called the Mormon Church
), founded in the U.S. in 1830 by Joseph Smith: its sacred Book of Mormon was represented by Smith as his translation of an account of some ancient American peoples by a prophet among them named Mormon," and the adjective Mormon
as "of the Mormons or their religion." Those two definitions are followed by: "--Mormonism n.
So from there I looked up -ism
and got seven definitions, the fourth of which seemed to fit best: "the doctrine, school, theory, or principle of." So it's pretty clear to me that the definition of Mormonism
is the doctrine, school, theory, or principle of the Mormon Church, which is a common name of the Church of Jesus Christ of Latter-day Saints. If you want to call it a movement you certainly may, but it looks to me like the dictionary clearly states that such a movement is inseparably connected to the LDS Church (much more than Christianity is tied to any Christian church), and therefore the leaders of the LDS Church have the perfect right to decide who is part of Mormonism and who is not.
The term "Mormon" predates the split into several different sects. While the Brighamite sect, which maintained the title The Church of Jesus Christ of Latter-day Saints, is by far the largest, and the organization most often referred to with the term "Mormon," I see no reason to deny those other groups that are also offshoots of Smith's original church the right to call themselves Mormons as well. Most use the Book of Mormon and still hold to the prophetic calling of Joseph Smith, after all.