Donald Kalish (December 4, 1919 – June 8, 2000) was an American logician, educator, and anti-war activist. Biography Born in Chicago, Illinois, Kalish earned his bachelor's and master's degrees in psychology and his doctorate in philosophy at the University of California, Berkeley. After teaching at Swarthmore College and at UC Berkeley, he joined the faculty of the University of California, Los Angeles in 1949. Kalish was perhaps best known for his outspoken opposition to the war in Vietnam and later, his opposition to U.S. military involvement in Nicaragua and Grenada. As chairman of the philosophy department of UCLA, Kalish hired Marxist political activist Angela Davis, an act that drew considerable controversy at the time. In 2001, the university's Philosophy Department initiated the Donald Kalish Prize for intellectual excellence, given to the most promising undergraduate student in the department. Kalish was a founder of the Concerned Faculty of UCLA. He served as a member of the University Committee on Vietnam, and as vice-chairman of Peace Action Council, Los Angeles. He is known for his leadership role with the Peace Action Council in a 1967 protest against President Lyndon Johnson's Vietnam policies at the Century Plaza Hotel in Los Angeles, which brought out 10,000 people. He was also an organizer of the 1967 March on the Pentagon to protest the Vietnam War and his activities were prominently chronicled in Norman Mailer's The Armies of the Night (1968). In 1967, Kalish signed a letter declaring his intention to refuse to pay taxes in protest against the U.S. war against Vietnam, and urging other people to also take this stand. Kalish was an expert on logic, set theory and the history of both subjects. With Richard Montague, he developed an innovative and elegant method of doing formal logical proofs by natural deduction. Kalish was a first-rate and devoted teacher, who taught with precision, compassion and enthusiasm. He was the proverbial "teacher's teacher," having the rare ability of being able to make even the most complex and arcane concepts readily comprehensible to his students. Most of his students loved his classes. In his logic and set theory classes, students did not see anything of his political opinions. He regularly gave his students his home phone number with the instruction that if they ever wanted to discuss an assignment, to call him anytime, day or night. Method of logical proof When a proof is done by