By today, I mean our milieu, which includes individuals of the last philosophical generation. Even if now deceased, they still influence our culture in 2013. An example on the mysticism side of the war is C. S. Lewis (1898-1963), whose writings Christians still cite.
By advocate of reason I mean someone who speaks informatively of reason, as a fact, and for reason, as a value. The advocate, when speaking of reason, can explain the basic mechanisms of reason and illustrate it with example applications.
INDIVIDUALS. The following individuals are candidates. They are worth investigating, according to my own reading or the recommendations by some of my associates on Facebook. Are they actually advocates of reason, and reason alone? Only further research will tell.
Brand Blandshard (1892-1987) was "an American philosopher known primarily for his defense of reason." (http://en.wikipedia.org/wiki/Brand_Blanshard)
W. T. Jones (1910-1998) was a professor of philosophy at the California Institute of Technology. He was the author of the five-volume History of Western Philosophy series. In his books, he defended reason, mostly in scattered passages.
Christopher Hitchens (1949-2011), one of the "New Atheists," was a purported defender of reason.
Sam Harris (b. 1967), one of the "New Atheists," is a purported defender of reason, but (I would say, tentatively) is actually a defender of secular forms of mysticism such as the notions of intuition and innate ideas.
Richard Dawkins (b. 1941), one of the "New Atheists," is a purported defender of reason.
Daniel Dennett (b. 1942), one of the "New Atheists," is a purported defender of reason.
One or more of my Facebook associates also recommended the following individuals as advocates of reason in the USA today. However, initially I have found no information showing that these individuals are indeed advocates, part-time or full-time, of reason and opponents of mysticism in the USA today. I welcome specific references to their writings, references that point out books, essays, chapters or even merely passages in which they explain the nature of reason, call for its exclusive use as a source of knowledge, and reject mysticism.
Thomas Sowell (b. 1930) is an author, sociologist, and economist writing in the USA: http://en.wikipedia.org/wiki/Thomas_Sowell.
Antal Fekete (b. 1932) is an author, economist, and professor of mathematics (Canada) who is active internationally: http://en.wikipedia.org/wiki/Antal_E._Fekete.
Eliyahu M. Goldratt (1947-2011), the author of Theory of Constraints and other fiction and nonfiction works, was a business consultant: http://en.wikipedia.org/wiki/Eli_Goldratt.
James (Jim) C. Collins (b. 1957), author of Good to Last, is a business consultant: http://en.wikipedia.org/wiki/James_C._Collins.
ORGANIZATIONS. The following organizations, apparently all institutions, seem to support reason, at least judging from their names and self-descriptions. Do they actually support reason? Do they advocate reason and reason alone as the means of gaining knowledge of the world?
Reason Foundation (founded in 1978 by Robert W. Poole, Jr.; Manuel S. Klausner; and Tibor Machan). The founders of Reason magazine published their first issue in 1968. "Reason Foundation is a nonprofit organization advancing free minds and free markets. . . . Reason Foundation's mission is to advance a free society by developing, applying, and promoting libertarian principles, including individual liberty, free markets, and the rule of law." The headquarters of the foundation is in Los Angeles. (http://reason.org/about) Initial sources: http://reason.org/ and http://en.wikipedia.org/wiki/Reason_Foundation
The Richard Dawkins Foundation for Reason and Science (founded in 2006) has this purpose: "The mission of the Richard Dawkins Foundation for Reason and Science is to support scientific education, critical thinking and evidence-based understanding of the natural world in the quest to overcome religious fundamentalism, superstition, intolerance and suffering." Initial sources: http://richarddawkinsfoundation.org/mission and http://en.wikipedia.org/wiki/Richard_Dawkins_Foundation_for_Reason_and_Science
Project Reason (founded in 2007 by Sam Harris and Annaka Harris) says its purpose is to spread "scientific knowledge and secular values in society." Further, "Project Reason seeks to encourage critical thinking and wise public policy through a variety of interrelated projects." By what means will the Project achieve its goals? "The foundation will convene conferences, produce films, sponsor scientific studies and opinion polls, publish original research, award grants to other charitable organizations, and offer material support to religious dissidents and public intellectuals—all with the purpose of eroding the influence of dogmatism, superstition, and bigotry in our world." A special focus of the foundation is countering religious dogmatism with critical thinking. (project-reason.org/about) Initial sources: http://www.project-reason.org/ and http://en.wikipedia.org/wiki/Project_Reason
Ari Armstrong, "Atheism Rises in U.S.—But What About Reason?," posted August 25, 2012 in the weblog of The Objective Standard. http://www.theobjectivestandard.com/blog/index.php/2012/08/atheism-rises-in-u-s-but-what-about-reason/
Alan Germani, "The Mystical Ethics of the New Atheists," The Objective Standard, Vol. 3, No. 3. http://www.theobjectivestandard.com/issues/2008-fall/mystical-ethics-new-atheists.asp
"Reason Foundation." http://en.wikipedia.org/wiki/Reason_Foundation
"Reason Foundation." http://reason.org/
"The Richard Dawkins Foundation for Reason and Science." http://richarddawkinsfoundation.org/
"The Richard Dawkins Foundation for Reason and Science." http://en.wikipedia.org/wiki/Richard_Dawkins_Foundation_for_Reason_and_Science
"Project Reason." http://www.project-reason.org/
"Project Reason." http://en.wikipedia.org/wiki/Project_Reason
"Sam Harris (Author)." http://en.wikipedia.org/wiki/Sam_Harris_(author)
Ari Armstrong, "Sam Harris Can Sound Like an Egoist; Too Bad He Isn't One," posted December 23, 2012 in the weblog of The Objective Standard. http://www.theobjectivestandard.com/blog/index.php/2012/12/sam-harris-can-sound-like-an-egoist-too-bad-he-isnt-one/
Ari Armstrong, "Sam Harris's Failure to Formulate a Scientific Morality, " The Objective Standard, Vol. 7, No. 4. http://www.theobjectivestandard.com/issues/2012-winter/sam-harris-unscientific-morality.asp
Ari Armstrong, "Sam Harris Couldn't Help But Smear Ayn Rand," posted May 17, 2012 in the weblog of The Objective Standard. http://www.theobjectivestandard.com/blog/index.php/2012/05/sam-harris-couldnt-help-but-smear-ayn-rand/
"Sam Harris." http://www.samharris.org/
Ari Armstrong, "Sam Harris Pointedly Defends Free Speech," posted September 22, 2012 in the weblog of The Objective Standard. http://www.theobjectivestandard.com/blog/index.php/2012/09/sam-harris-pointedly-defends-free-speech/
Suggestions for additions, deletions, or modifications are welcome in the comment thread.
Author, The Power and the Glory: They Key Ideas and Crusading Lives of Eight Debaters of Reason vs. Faith, http://www.reasonversusmysticism.com/