If you are looking into Zen, you may find this article on Sanbokyodan Zen helpful. It’s “Sanbôkyôdan Zen and the Way of the New Religions” and can be found at www.geocities.com/Athens/Forum/9148/sharf-95.html or www.nanzan-u.ac.jp/SHUBUNKEN/jjrs/jjrs-cumulative-list.html [article number 456]. The information I found here is new to me and helped me become more critical of Zen in America (and Zen in general) and so-called Zen masters.
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Since the full article is rather lengthy, you may prefer a summary at www.darkzen.com/Articles/sanbo.htm .