Historical views on sleep

Interestingly, human sleep patterns have changed over the centuries, as our attitudes and cultural ideas about sleep have transformed. Discover some interesting facts about how sleep has been viewed and studied throughout history.

Blood retracting

Ancient Greek philosophers attempted to understand the mysteries of sleep through studying the body and creating theories to explain what they saw. Sometimes they got things right, but often their understanding seems strange to us now.

Alcmaeon of Croton postulated that sleep related to the shifting of blood flow. He argued that sleep was brought about as our blood ‘retreated’ from the surface of the body into the interior areas – like the brain. We woke up once the blood diffused to the surface again. Another philosopher, Hippocrates, added to this theory the idea that the blood retreated from your limbs in order to enter the abdomen to be warmed up, and this physical process induced sleep.


sleepezi blood circulation

Sleep as digestion

The Greek philosopher Aristotle believe that sleep originated in the abdomen as part of a digestive process called “concoction.” He wrote that sleep was vital for physical vitality, lively spirits and increased longevity. Aristotle’s beliefs about sleep persisted for many hundreds of years, and sleep as medicine was a common prescription from Italian doctors. People were often encouraged to retire early for the best effects.

Sleep in two parts

Throughout much of history, a common sleep pattern among Western European peoples was to enjoy a wakeful period of quiet contemplation in the middle of the night. This break between “first sleep” and “second sleep” was a time to read a book, talk with the family or visit neighbours. It was also a period where the dreams of the first half of the night were discussed and divined. This type of sleep may be ancient, with references to it in Homer’s Odyssey.

  sleepezi second sleep

Demonic possession

During the medieval period, sleep could be downright dangerous. Before sleeping disorders were well understood, they were often thought to derive from divine sources. The ‘mare’ or ‘night hag’ was a demonic creature who would sit on your chest and immobilize your as you woke up. This malevolent figure turns up in many cultures as a way to describe sleep paralysis.

Dreams too, could be demonic attacks – medieval Christians believed the mind and spirit were vulnerable during sleep, and that while many dreams were direct messages from God, some came from the devil.

Sleep is such a fascinating subject, and as you’ve seen, it’s engaged some of the greatest thinkers since the beginning of time. Whatever your beliefs around sleep, know that it’s vital for your health to get it.