A proponent of nonviolence, he influenced students and heroes of the anti-war,[1] civil rights, and peace movements,[2] including Martin Luther King Jr.,[3] David Harris,[4][5][6] Bob Dylan, John Lennon, Lawrence Ferlinghetti, Allen Ginsberg, Daniel Ellsberg, Thomas Merton,[7] and Joan Baez with whom he formed the Institute for the Study of Non-violence.

[10] Sandperl was a longtime resident of Palo Alto and Menlo Park, where he was an oracular presence at Kepler's bookstore,[11] Peninsula School and other venues in the Stanford area, and influenced many young people who grew up in his community in the 1950's and 1960's, including Joan Baez and John Markoff.

In the Bay Area, he was a fixture at Kepler's, a bookstore near Stanford that became a center of counterculture, drawing the youth and students at nearby universities to listen to his ideas of non-violence and fascination with Mahatma Gandhi.

[12] Protesting at a Quaker meeting in Palo Alto in 1959, urging them to refuse payment of war taxes,[10] Sandperl met Joan Baez when she was a senior in high school and through their interests in various philosophies and political causes they developed a friendship.

[13] The school invited a small number of students each year (in order of applications received) to learn the principles of nonviolence, partake in readings, meditation, and discussion.

The nationally famous catholic monk and non-violent activist, Thomas Merton, met with Sandperl and Baez in December 1966 at the Abbey of Gethsemani in Kentucky where he lived.

[7] In 1968, Sandperl, Joan Baez and David Harris organized a nation-wide speaking tour to urge draft age men to refuse induction.

Sandperl, who had served 45 days for blocking the induction center in Oakland, CA, advised him that it could be managed, and it was even possible to organize among the other prisoners if one took care not to be disruptive, because the guards just didn't want any trouble.

On June 13, 1971, the unknown man's face and the Pentagon Papers he had leaked were on the front page of the New York Times, and the resistance had landed its most solid blow yet against the war machine.

[21] His book is really a series of essays, in the form of journal entries sent as letters to a young friend, on the subject of how to live, what to do, and the nature of a life of critical purpose well-lived.

In the manner of Montaigne, the inventor of this essay form, it discourses on Sandperl's wide-ranging passionate investments in the philosophy and practice of nonviolence, the study of political history and its dangerous characters, and his reading: he was extraordinarily well-read, worked in a bookstore and lived in a tiny apartment crammed with thousands of books.