From the investigation of sleep stages and the endogenous circadian pacemaker to the discovery of the sleep- and wake-promoting centers of the hypothalamus, Dr. Lavie covers most of the major findings regarding the regulation and possible functions of sleep. The scientific drama behind these discoveries is nicely captured in the narratives of the personal lives and intellectual quests of modern sleep scientists like Michael Jouvet, William Dement, and Allan Rechtschaffen. Dreams, perhaps the most fascinating aspect of sleep, are examined from both philosophical and scientific points of view.