Never give way to vain laughter. I have seldom laughed aloud for twenty or thirty years without regretting it, and I always blush for those who laugh aloud without meaning. I am often full of joy and gladness, and were I to give way to the promptings of my nature at such times, it would lead to unreasonable levity which would be a source of mortification and sorrow to me. I noticed that the brethren gave way to that laugh which I choose not to hear.
[Source: Journal of Discourses. Liverpool, England, 1853-86. 9:290-292, in The Complete Discourses of Brigham Young, Ed. Richard S. Van Wagoner, Smith-Pettit Foundation, Salt Lake City (2009), http://bit.ly/BY-discourses]