Thornton received a Bachelor of Arts in Latin from the University of California at Los Angeles in 1975, and a PhD in Comparative Literature in 1983. He had studied Greek, Latin, and English literature for his doctorate.
Currently Thornton is research fellow and W. Glenn Campbell and Rita Ricardo-Campbell National Fellow (2009–2010 and 2010–2011) at Stanford University's Hoover Institution. He is a Shillman Journalism Fellow at the David Horowitz Freedom Center.
Thornton has lectured at the Smithsonian Institution in Washington, D.C. He also appeared on ABC's Politically Incorrect with Bill Maher, and is a contributor to the conservative website CaliforniaRepublic.org.
Thornton has described his opinions as opposed to the dominant, mainstream historical tradition about the Enlightenment. He is an admirer of historian Christopher Dawson. He also subscribes to the 'Athens versus Jerusalem' thesis of Leo Strauss, in which the interplay between classical Greek ideologies of rationality and the Judaeo-Christian spiritual philosophies resulted in the creation of Western civilization.
Thornton believes that the declining belief in interpersonal ideals such as national pride and in religious ideals such as Christianity has led non-American Westerners to either substitute "political religions" such as communism and fascism into their lives or abandon having moral ideals altogether. This, in his opinion, weakens them against pressure from threats such as increasing immigration to Europe by Muslims that have higher birth rates than native Europeans. He has said, "If all of their goods are material, right, what material good is worth dying for and what material good is worth killing for?"
Thornton was a strong critic of the Obama administration. He wrote on February 10, 2009:
So far, we have heard nothing from the Obama team that suggests they will be any more successful than previous administrations in thwarting the designs of our enemies. Instead, look for more talk, more summits, even more agreements that, in the end, will leave us weaker and our enemies stronger.
Thornton has published several well-received books.
- Eros: The Myth of Ancient Greek Sexuality (Westview Press, 1997)
- Plagues of the Mind: The New Epidemic of False Knowledge (ISI Books, 1999)
- Greek Ways: How the Greeks Created Western Civilization (Encounter Books, 2000)
- Humanities Handbook (Prentice-Hall, 2000)
- Bonfire of the Humanities. Rescuing the Classics in an Impoverished Age, with John Heath and Victor Davis Hanson (ISI Books, 2001)
- Searching for Joaquin: Myth and History in California (Encounter Books, 2003)
- Decline and Fall: Europe's Slow Motion Suicide (Encounter Books, 2008)
- The Wages of Appeasement: Ancient Athens, Munich, and Obama’s America (Encounter Books, 2011) ISBN 1-59403-519-9
- Democracy's Dangers and Discontents: The Tyranny of the Majority From the Greeks to Obama (Stanford, California: Hoover Institution Press, 2014).
Thornton has written for numerous publications including National Review Online, Heterodoxy, The National Herald, The Washington Times, The Los Angeles Times, Helios Magazine, Arion, The Jewish Press, The San Francisco Examiner, The American Enterprise, The University Bookman, Religious Studies Review, Intercollegiate Review, The American Journal of Philology, City Journal, and FrontPage Magazine.
- "Hoover Institution Research Fellow: Biography". Hoover Institution. Retrieved 2011-10-27.
- Biography Archived August 14, 2006, at the Wayback Machine. California State University, Fresno: Bruce Thornton's page at Fresno State. Accessed October 31, 2014.
- Peter Robinson interviews Fresno State Classicist Bruce Thornton about his new book Decline and Fall: Europe's Slow Suicide Archived October 11, 2008, at the Wayback Machine. Hoover Institution: Uncommon Knowledge. Filmed on March 6, 2008. Accessed August 19, 2009.
- Thornton, Bruce (February 10, 2009). "Foreign Policy as Magical Thinking". FrontPage Magazine. Retrieved August 19, 2009.
- Hoover Institutin: Democracy's Dangers and Discontents
- "Bruce S. Thornton". City Journal. Archived from the original on October 1, 2009. Retrieved August 19, 2009.
- "Bruce Thornton". FrontPage Magazine. Archived from the original on July 9, 2012. Retrieved August 19, 2009.