"A beautiful, engrossing and challenging work whose topic is of increasing importance and relevance today...This unsettling book truly merits a wide scholastic as well as a general reading."
-- Francis X. Barron, Professor Emeritus in Psychology, UCSC, Harvard

"Very exciting...fine scholarship in a difficult area."
-- Terence McKenna, author of Food of the Gods

"No researcher to date has tackled the subject with Heinrich's painstaking ingenuity. His conclusions are as fascinating as they are certain to be controversial."
-- Professor Huston Smith, Visiting Professor of Religious Studies and Professor of Religious Studies and Professor of Religion and Philosophy Emeritus at Syracuse.