Horace Meyer Kallen (August 11, 1882 – February 16, 1974) was an American philosopher.
Born in the then German Bernstadt, Silesia (now Bierutów) to Jacob David Kallen and Esther Rebecca (Glazier), an Orthodox rabbi and his wife, Kallen came to the United States as a child in 1887. He studied philosophy at Harvard University where he was a student of George Santayana, earning his B.A. (magna cum laude) in 1903. After two years of study at Princeton University, he returned to Harvard for graduate study and worked as Santayana's assistant. Kallen received his Ph.D. from Harvard in 1908 and was awarded a Sheldon Travelling Fellowship to study at Oxford University. He was also a lifetime friend of Alain Locke, whom he met at Harvard and who was the first African American Rhodes Scholar—and the only one until the 1960s.
He lectured in philosophy at Harvard from his graduation until 1911, occasionally working as a logic instructor at Clark College in Worcester, Massachusetts. In 1911, he moved to instruct philosophy at the University of Wisconsin–Madison until 1918, when he was named a professor at The New School in New York City as a founding member, where he remained for the rest of his career.
A Pluralist, Kallen opposed any over-simplification of philosophical and vital problems. According to Kallen, denying complications and difficulties is to multiply them, as much as to deny reality to evil would aggravate evil.
He advanced the ideal that cultural diversity and national pride were compatible with each other, and that ethnic and racial diversity strengthened America. His critics pointed out his disingenuousness since as a Jewish intellectual and member of the Zionist Organization of America his vision of multicultural America was quite the opposite of his vision of the Jewish state of Israel as a totally Jewish nation. Kallen is credited with coining the term cultural pluralism.
He was acquainted with William James, whose last unfinished book he edited. He married Rachel Oatman van Arsdale in 1926. In 1939 he became acquainted with Immanuel Velikovsky and became a lifelong friend, informal literary advisor, mentor, and advocate. He was a member of the American Philosophical Society, the Western Philosophical Society, the Society for Psychical Research, the Zionist Organization of America, the Palestine Development Council, and the National Council of the League of Nations Association. He served on congressional committees on international peace and was a part of many think tanks and study groups on questions ranging from philosophy and law to labor relations.
Kallen died in Palm Beach, Florida.
Selected works 
- Some of his works
- Democracy Versus the Melting-Pot, 1915.
- Zionism and World Politics, William Heinemann, 1921.
- Indecency and the Seven Arts:And Other Adventures of a Pragmatist in Aesthetics, 1930.
- Decline and Rise of the Consumer, 1936.
- Art and Freedom, 1942.
- Modernity and Liberty, 1947.
- The Liberal Spirit, 1948.
- Ideals and Experience, 1948.
- The Education of Free Men, 1950.
- Patterns of Progress, 1950.
- "Of Them Which Say they Are Jews,": and Other Essays on the Jewish Struggle for Survival, Bloch Pub. Co., 1954.
- Cultural Pluralism and the American Idea, 1956.
- Utopians at Bay, 1958.
- Liberty, Laughter, and Tears, 1968.
- Creativity, Imagination, Logic: Meditations for the Eleventh Hour, 1973.
- "Socrates and the Street Car," The Mid-West Quarterly, Vol. 1, No. 4, July 1914.
- "Democracy Versus the Melting-Pot: A Study of American Nationality," Part II, The Nation, Feb. 25, 1915.
- "Philosophers," The American Mercury, December 1926.
- "The Hither of the Beyond," The Bookman, February 1928.
- "Fear, Freedom, and Massachusetts," The American Mercury, November 1929.
- "Toward the Four Freedoms," The Saturday Review, May 23, 1942.
- "The War Against the Chain-Gang of Production," The Saturday Review, September 9, 1944.
- "How I Bet My Life," The Saturday Review, October 1, 1966.
Bibliography: see also a special Symposium on Horace M. Kallen in Modern Judaism, Vol. 4, No. 2. (May, 1984)
See also 
- Lamont, C., ed. Dialogue on George Santayana. New York: Horizon Press (1959) 13-17.
- Louis Menand. The Metaphysical Club: A Story of Ideas in America. (New York: Farrar, Staus and Girroux, 2001) p. 388
- Gilbert, James (1997). Redeeming Culture: American Religion in an Age of Science, University of Chicago Press. ISBN 0-226-29320-3. Chap. 8, Two Men of Science, p. 175, namely Harlow Shapley and Kallen.
- Gilbert, James (1997). Redeeming Culture: American Religion in an Age of Science, University of Chicago Press. ISBN 0-226-29320-3. Chap. 8, Two Men of Science, pp. 177-181, namely Harlow Shapley and Kallen.
Further readind 
- Fishman, Donald A. "Mainstreaming Ethnicity: Horace Kallen, the Strategy of Transcendence, and Cultural Pluralism," Southern Communication Journal, Volume 69, Issue 2, 2004.
- Konvitz Milton, Ridvas, ed. The Legacy of Horace M. Kallen, Fairleigh Dickinson University Press, 1987.
- Kronish, Ronald. "John Dewey and Horace M. Kallen on Cultural Pluralism: Their Impact on Jewish Education," Vol. 44, No. 2, Spring, 1982.
- Maxcy, Spencer J. "Horace Kalien's Two Conceptions of Cultural Pluralism," Educational Theory, Volume 29, Issue 1, January 1979.
- Pianko, Noam. "The True Liberalism of Zionism”: Horace Kallen, Jewish Nationalism, and the Limits of American Pluralism," American Jewish History, Volume 94, Number 4, December 2008.
- Ratner, Sidney. "Horace M. Kallen and Cultural Pluralism," Modern Judaism, Vol. 4, No. 2, May, 1984.
- Schmidt, Sarah. Horace M. Kallen: Prophet of American Zionism, Carlson Pub., 1995.
- Toll, William. "Horace M. Kallen: Pluralism and American Jewish Identity," American Jewish History, Volume 85, Number 1, March 1997.
- Zdiara, Kevin. "Inventing Pluralist America," Jewish Ideas Daily, August 8, 2012.
- Papers of Horace Meyer Kallen.; RG 317; YIVO Institute for Jewish Research, New York, NY.