Man's wondering about his dreams has been singularly intertwined with the history of psychiatry, and understanding of one has grown pari passu with that of the other. Whatever sophistication concerning the meaning of dreams thus attained, until very recently our view of dreaming itself remained essentially that granted by common experience. The traditional conception of dreaming, even as it was assumed in Freud's penetrating studies, described an occasional, unpredictable, fleeting, and mysterious psychic anomaly. Over the past decade experimental tools more searching than common experience have begun to amend this traditional conception. This is intended as a cursory review of the amassing evidence which suggests that dreaming is one facet of a substantial, predictable, universal, and basic biological function. Beyond that purpose the rest is speculative flight, striving for some distant glimpse of possible implications of this new conception for psychiatry. Dreaming as an Organismic