Philosopher and peace campaigner Shunsuke Tsurumi died of pneumonia at a Kyoto hospital last Monday, his family said Friday. He was 93.

After studying philosophy at Harvard University in the United States, graduating in 1942, Tsurumi held positions as an assistant professor at the state-run Kyoto University and at the Tokyo Institute of Technology.

In 1960, he resigned from the latter in protest at the adoption by the Diet of a revised security treaty between Japan and the United States.

Later, Tsurumi served as professor at Doshisha University in Kyoto. In 1965, he established with influential writer Makoto Oda and others a citizens' movement called the Japan "Peace for Vietnam!" Committee, known by its Japanese acronym Beheiren, to seek peace in Vietnam, where U.S. forces were fighting a war against communist forces.

He left academic life in 1970, resigning as professor from Doshisha University, and devoted himself to writing about philosophy and other subjects.

In 2004, Tsurumi founded with Nobel-winning novelist Kenzaburo Oe and others the Article 9 Association, a body to defend the country's pacifist Constitution, which renounces war.

Tsurumi was a grandson of politician Shinpei Goto (1857-1929), who served as the first president of the South Manchuria Railway Co., built by Japan in what was then called Manchuria in northeastern China.

His father was Yusuke Tsurumi (1885-1973), who served as health minister and a member of both chambers of the Diet. His sister Kazuko (1918-2006) was a sociologist.