As the editor of a collection of essays on the consciousness expanding substances, I naturally hope that my efforts will generate more light than heat in the controversy over their uses and control. But reading, though stimulating and provocative, is of course no substitute for direct experience. Because of my own experiences with these mind-and-senses openersand a goodly number of leading psychedelic investigators, both lay and professional, would concur—I am convinced that taking them in a planned and supervised, but permissive and relaxed setting is a minimal prerequisite, whether one is a doctor or a ditch digger, for a reasonable and critical understanding of their properties and potentials.