The greatest achivement in life – five traditions of mysticism by R. D. Krumpos (2012) consists of a series of essays based on talks with mystics in 12 countries and 180 books. Many people were consulted, including the directors of a Buddhist Center and of the Eastern Orthodox theological institute at two major universities, a Vedanta Society swami, the director of an Islamic Center, the director of a Reform theological college, the abbot of a Theravada temple, a Cistercian monk, a Hindu abbess, a Sufi shaykha, and a professor at a university for Judaism, plus 10 professors who each teach courses on comparative mysticism