Robert Baker Dairyu Chotan Aitken Rōshi (June 19, 1917 – August 5, 2010) was a Zen teacher in the Harada-Yasutani lineage.

He was a socialist and anarchist who advocated for social justice for homosexuals, women and Native Hawaiians throughout his life, and was one of the original founders of the Buddhist Peace Fellowship.

A guard at one of the internment camps let him borrow a copy of R.H. Blyth's book Zen in English Literature and the Oriental Classics.

[5] In another internment camp in Kobe, Japan, in 1944 he met its author, Reginald Horace Blyth, with whom he had frequent discussions on Zen Buddhism and anarchism.

Aitken decided to not pay the portion of his taxes that went to the Defense Department of the U.S because he opposed the war in Vietnam and arming the military.

[13][14] In 1960 Soen Nakagawa Roshi asked young monk Eido Tai Shimano to travel to Honolulu to assist at the Diamond Sangha center.

He was an outspoken critic of the Vietnam War, and became a strong opponent of the nuclear arms race between the United States and the Soviet Union.

He was among the earlier proponents of deep ecology in religious America, and was outspoken in his beliefs on the equality of men and women.

In 1978 Aitken helped found the Buddhist Peace Fellowship, an organization that advocates conflict resolution globally.

[4] Aitken Roshi retired in 1996 and spent some of his final years in Palolo, Hawaii, where he could be looked after and interact with some of his students.