Sleep
For much of its run through history, sleep was understood as a state that temporarily released the soul from the body. Virtually all religious traditions view dreams as a vehicle for accessing spiritual visions (Bulkeley 2008). In ancient Greece, dreams could yield either a magical inward sight or a message from the gods (Hacking 2002); reports of Hopi and Ojibwa dreams also reveal high spiritual content (P. Burke 1997). In early modern England and France, the sleeping body was popularly viewed as a battleground in which divine or demonic forces could seize the soul, prefiguring its ultimate destiny after death (Handley 2016, 77). But little medical attention was paid to the lumpish, nondreaming aspects of sleep other than how to manipulate it through hygiene, diet, or potions (Kroker 2007, 25–29, 60–64). According to the Aristotelian tradition, which persisted through much of early modern thought, while dreams could carry dreamers into the empyrean, sleep itself put human flesh on a par with plants and animals (Sullivan 2012). Recently, this leveling has extended to computers and other machinery that are said to be in “sleep mode.”