Medical, legal, and religious experts have recently been confronted with the problem of the so-called "mystic drugs," that seem to produce, without any apparent physical harm, changes of consciousness comparable to the highest forms of aesthetic and religious experience. This book, y one of the world's leading investigators of the psychology of religion, is an evaluation of these drugs both objectively and from the vantage of the author's own personal experiments.

The author's record of his own experiments is a vivid, lyrical account of valuable transformations that can occur in the human mind. The heightening of consciousness ranged all the way from aesthetic insights into nature to a philosophical view of existence as a comedy at once diabolic and divine, resolving itself into "a cosmology not only unified but also joyous."

Timothy Leary and Richard Alpert, formerly of the psychology department at Harvard University, have written the Foreword. The book is enhanced by photographs of natural forms, which in themselves stand as an abstract expression of the intriguing text.