Called "America's wisest and most respected authority on psychedelics and their use," James Fadiman has been involved with psychedelic research since the 1960s. In this guide to the immediate and long-term effects of psychedelic use for spiritual (high dose), therapeutic (moderate dose), and problem-solving (low dose) purposes, Fadiman outlines best practices for safe, sacred entheogenic voyages learned through his more than 40 years of experience - from the benefits of having a sensitive guide during a session (and how to be one) to the importance of the setting and pre-session intention. Fadiman reviews the newest as well as the neglected research into the psychotherapeutic value of visionary drug use for increased personal awareness and a host of serious medical conditions, including his recent study of the reasons for and results of psychedelic use among hundreds of students and professionals. He reveals new uses for LSD and other psychedelics, including extremely low doses for improved cognitive functioning and emotional balance. Cautioning that psychedelics are not for everyone, he dispels the myths and misperceptions about psychedelics circulating in textbooks and clinics as well as on the internet. Exploring the life-changing experiences of Ram Dass, Timothy Leary, Aldous Huxley, and Huston Smith as well as Francis Crick and Steve Jobs, Fadiman shows how psychedelics, used wisely, can lead not only to healing but also to scientific breakthroughs and spiritual epiphanies.