The establishment of a comprehensive multidisciplinary knowledge base on these substances is an essential step to furthering understanding of both their potential and their risks. This issue of the Journal of Psychoactive Drugs brings together a collection of articles addressing key questions concerning the nature and potential uses of hallucinogens. The relevance of shamanistic belief systems and technolo­gies to our own evolving understanding of this unique phenomenon is explored, along with explanations of how modem neurobiological science conceptualizes their mechanism of action. As efforts begin to reopen psychedelic research in an environment somewhat less fraught with media sensation­alism and professional vacillation, there is hope that the application of state-of-the-art research methodologies to this neglected area of investigation will allow the question of the hallucinogens' capacity to facilitate healing to be reexamined in an atmosphere of objectivity by contempo­rary researchers.