“I admire men and women who have developed the questing spirit, who are unafraid of new ideas as stepping stones to progress. We should, of course, respect the opinions of others, but we should also be unafraid to dissent – if we are informed. Thoughts and expressions compete in the marketplace of thought, and in that competition truth emerges triumphant. Only error fears freedom of expression. . . This free exchange of ideas is not to be deplored as long as men and women remain humble and teachable. Neither fear of consequence or any kind of coercion should ever be used to secure uniformity of thought in the church. People should express their problems and opinions and be unafraid to think without fear of ill consequences. . . . We must preserve the freedom of the mind in the church and resist all efforts to suppress it.”

(Hugh B. Brown, The Abundant Life: The Memoirs of Hugh B. Brown, ed. Edwin B. Firmage (Salt Lake City: Signature Books, 1988), 137-39; Hugh B. Brown, “An Eternal Quest—Freedom of the Mind,” a speech delivered at Brigham Young University, 13 May 1969, in Speeches of the Year (Provo, UT): Brigham Young University Press, 1969); rpt. In Dialogue: A Journal of Mormon Thought 17 (Spring 1984): 77-83

http://aims.byu.edu/sites/default/files/foundationdocuments/An_Eternal_Quest--Freedom_of_the_Mind--Hugh_B_Brown.pdf

"Brothers and sisters, as good as our previous experience may be, if we stop asking questions, stop thinking, stop pondering, we can thwart the revelations of the Spirit. Remember, it was the questions young Joseph asked that opened the door for the restoration of all things. We can block the growth and knowledge our Heavenly Father intends for us. How often has the Holy Spirit tried to tell us something we needed to know but couldn’t get past the massive iron gate of what we thought we already knew?"

Elder Uchtdorf

https://www.lds.org/broadcasts/article/worldwide-leadership-training/2012/01/acting-on-the-truths-of-the-gospel-of-jesus-christ?lang=eng

“We have been blessed with much knowledge by revelation from God which, in some part, the world lacks. But there is an incomprehensibly greater part of truth which we must yet discover. Our revealed truth should leave us stricken with the knowledge of how little we really know. It should never lead to an emotional arrogance based upon a false assumption that we somehow have all the answers–that we in fact have a corner on truth, for we do not.”

Hugh B. Brown, “An Eternal Quest – Freedom of the Mind,” speech given to the BYU student body on May 13, 1969
http://president.byu.edu/documents/brown.htm