Of all the disciplines that I studied, practiced, learned, Zen was the essential one. It was not so much an influence on me, rather it created space. It allowed those things that were there to be there. It gave some form to my experience. And it built up in me the critical mass from which was kindled the experience that produced est.
Interview with William Warren Bartley, cited in Bartley, William Warren (1978). Werner Erhard: the Transformation of a Man: the Founding of est. New York: Clarkson N. Potter, Inc.. p. 121. ISBN 0-517-53502-5.