Being able to enjoy eight hours’ straight slumber is today seen as something of a superpower. But, as Justin Pollard reveals, attitudes to sleep and its medical importance have evolved over the centuries…
In our modern 24/7 world, it can sometimes seem as if we’ve finally finished the job Macbeth started, and murdered sleep. But surely the lazy days of history can provide some tips for enjoying a restful night of slumber?
One advantage enjoyed by our ancestors was that nights were darker and quieter in the past. Even so, people did suffer from sleep problems. We know from Egyptian medical papyri that drugs extracted from the opium poppy, belladonna and nightshade were available, all of which could help with slumber – but also, if taken incautiously, cause a more final and permanent rest.
Ancient ideas
The ancient Greeks thought a lot about the subject, too. Hypnos, the god of sleep, makes his first known appearance in Book 14 of Homer’s Iliad. Sleep also formed the basis of medical treatment at the temples of Asklepios. The sick were brought to sleep at these sites where, during the night, they would be treated with drugs by priests. Dreaming of Asklepios, patients would wake up cured. Or so the theory went.
The ancient Greeks also pondered the factors that make for a good night’s sleep. Aristotle thought that ingested food emitted fumes, which entered the brain through blood vessels, causing sleepiness. (Interestingly, recent studies of several foods such as walnuts and fatty fish suggest that they do promote sleep.)
Democritus of Abdera thought that insomnia was caused by an unhealthy diet – and modern sleep specialists also urge us to avoid consuming some substances, particularly in the hours before bed. As long ago as the 17th century, English physician Sir Thomas Willis noticed that strong coffee seemed to keep him awake.
Assuming we’ve dosed up on walnuts and avoided coffee, how long should we sleep? In the late 12th century, Moses ben Maimon – also known as Maimonides, and the most influential Jewish physician working in the Arab world – suggested that a single period of eight hours’ sleep, ending just before sunrise, was the perfect amount.
Recent studies suggest that, through much of the pre-modern period, the norm was not one sleep a night but two. The idea of ‘first sleep’ and ‘second sleep’ appears in numerous medieval and early modern diaries and letters, and is mentioned in Chaucer’s Canterbury Tales. This ‘biphasic sleep’ was recorded across the world, in Africa and Australia as well as Europe. First sleep, lasting a couple of hours, was usually taken between 9pm and 11pm, depending on the season. After this came a wakeful period known as ‘the watch’, which could be filled with letter-writing or praying – a quiet and contemplative time of day.
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For the working classes, ‘the watch’ provided another chance to catch up on chores. And for the young (or young at heart) in families, who may all have shared one bed, this was a moment in which a little intimacy might be enjoyed – provided, that is, you weren’t interrupted by the house-breakers and thieves who also used this time for a bit of after-hours work.
Squeezed slumber
By the 19th century, the advent of shift working, resulting in the need to adhere to ‘clock time’ rather than simply working to daylight hours, began to affect natural rhythms. With chores still to be done after work, and improved artificial lighting in which to do them, sleep became more compressed. Bedtime got later, but morning started at the same time each day, regardless of the season or whether the sun was actually up. Sleep was now squashed into a shorter period, and the era of monophasic (single) sleeps began.
If all this seems a little depressing, next time you find yourself wide awake in the middle of the night, remember that you’re not an insomniac – you’re just channelling your inner ancestor!
This article was first published in the October 2023 issue of BBC History Revealed