Nathaniel Kleitman, “Sleep and Wakefulness“, 1963 was the subject of an earlier blog post. Here I present Sigmund Freud, “The Interpretation of Dreams”, 1899 a nonfiction science book. “The Interpretation of Dreams”, 1899 is the most popular writing of the psychiatrist Sigmund Freud. REM (rapid eye movements) are a unique phase of sleep, characterized by the propensity of a sleeper to dream vividly. Nathaniel Kleitman was the discoverer of REM vivid-sleeper dreaming. The sleep-wake propensity is a biological rhythm to synchronize an organism to the Earth’s 24-hour light/dark cycle and the 12-month hot/cold cycle. Aestivation (summer-sleep) and hibernation (winter-sleep) are terms used in the 12-month hot/cold cycle. Sigmund Freud, “The Interpretation of Dreams”, 1899 is a study of the 24-hour light/dark cycle when REM vivid-sleeper dreaming occurs. These observation of the patient behavior are used in psychiatric treatment. “Dream drama” analysis is the conveying of one’s “dream diary” to the therapist.