All for Australia (1984)
“Men in the mass never brook the destructive discussion of their fundamental beliefs, and that impatience is naturally most evident in those societies in which men in the mass are most influential. Democracy and free speech are not facets of one gem; democracy and free speech are eternal enemies.”
1940s–present, Introduction to Nietzsche's The Antichrist
Help us to complete the source, original and additional information
H.L. Mencken 281
American journalist and writer 1880–1956Related quotes

"Stay Quiet and You'll Be Okay" http://www.steynonline.com/6943/stay-quiet-and-youll-be-okay steynonline.com (9 May 2015)

Concurring, Whitney v. California, 274 U.S. 357, 376 (1927).
Judicial opinions

"The One Un-American Act," Speech to the Author's Guild Council in New York, on receiving the 1951 Lauterbach Award (December 3, 1952) http://ala.org/ala/aboutala/offices/oif/foryoungpeople/theoneunamerican/oneunamerican.cfm
Other speeches and writings

Political, Moral, and Miscellaneous Reflections (1750), Moral Thoughts and Reflections

Source: The Winds of Limbo aka The Fireclown (1965), Chapter 4 (p. 151)

Islamic fundamentalism is incompatible with freedom and Western liberal democracy https://web.archive.org/web/20070927174923/http://www.tfa.net/pdfs/60610.pdf (2006)
2006

Collaborations with others, Science Order, and Creativity (1987)

“There can be no free speech in a mob: free speech is one thing a mob can't stand.”
"Quotes", The Educated Imagination (1963), Talk 6: The Vocation of Eloquence