Among the Latter-day Saints, the preaching of false doctrines disguised as truths of the gospel, may be expected from people of two classes, and practically from these only; they are:
First – The hopelessly ignorant, whose lack of intelligence is due to their indolence and sloth, who make but feeble effort, if indeed any at all, to better themselves by reading and study; those who are afflicted with a dread disease that may develop into an incurable malady – laziness.
Second – The proud and self-vaunting ones, who read by the lamp of their own conceit; who interpret by rules of their own contriving; who have become a law unto themselves, and so pose as the sole judges of their own doings. More dangerously ignorant than the first.
Beware of the lazy and the proud; their infection in each case is contagious; better for them and for all when they are compelled to display the yellow flag of warning, that the clean and uninfected may be protected. — Joseph F. Smith, Gospel Doctrine, p. 373