The title ""alternate"" rather than ""altered"" was deliberately selected for this volume of essays by distinguished scientists to counter the assumption that ordinary consciousness is the norm and everything else deviation. This sets an overall positive tone to the volume. The contributors, invited to discuss their points of view at a conference sponsored by the Drug Abuse Council in Washington, D.C., include experienced enthusiasts like Andrew Weil, the well-known psychologists Karl Pribram and Jerome Singer, psychiatrists (such as Zinberg), and other scholars. Anthropologist Peter Furst contributes a fascinating chapter on the widespread use of hallucinogenic drugs and other ways of inducing trance states in the Americas, hypothesizing that this represents the long tradition of shamanism in hunter-gatherer societies. The authors, like the proverbial elephant-feelers, approach the meaning of consciousness with the terminologies, ways of classification, and methodologies peculiar to their disciplines. So the biofeedback specialist sees a way of tapping that technique to pin down patterns of nervous system activity associated with meditation or drug-induced states. The computer-minded psychologist talks in terms of open and closed loops; the personality-oriented psychologist thinks of scales of introversion-extroversion as clues to individual differences in the contents of consciousness. The writing throughout is of an unusually high caliber and the reader senses that the conference led to intriguing and provocative exchanges of ideas. In the trendy marketplace of turn-on books it is gratifying to report that here is one that brings intellectual curiosity and creative approaches to the study of the phenomenon of consciousness.