Despite huge advances in sleep science and our understanding of the human brain, our understanding of what on earth specifically makes us shut our eyes and vividly hallucinate for 8 hours a night remains pretty mysterious. It's been suggested that we evolved dreaming as a way of consolidating memories, helping us solve problems we couldn't deal with consciously, or performing necessary brain repair functions. It remains, however, one of the oddest parts of universal human experience. While newborns look as if they're dreaming, it seems that dreaming actually develops into something sophisticated in early childhood, requiring advanced brain connections that don't really exist until we're perhaps 4 or 5. The fact that even in the age of MRIs dreams remain pretty opaque indicates just how complex they are; so it's remarkable to see the insights and beliefs assigned to dreaming by ancient civilizations. Some of them, needless to say, are extremely odd.
The idea that dreams could predict the future is one of the most ancient ideas around; the practice of "incubation" — of staying in a certain sacred place and doing rituals to welcome prophetic or helpful dreams — has been found across various ancient cultures. However, there's a lot more to dreams and their history in civilization than that. From spells to demons, livers to pregnancy, here are some of the oddest beliefs about dreams; your grandmother's insistence that bad dreams come from indigestion looks basically sane by comparison.
You Could Banish Bad Dreams Using Spells, Cobras And Pig Liver
The ancient Egyptians were highly conscious of dreams, and often intent on getting rid of nightmares any way they could. Healing papyruses record incantations that attempt to banish any violent or upsetting dreams before the sleeper lays down, using an intriguing combination of incantation, pig liver, and statues of rearing cobras (no, thankfully not any real ones).
The London Medical Papyrus records a spell that was designed to prevent miscarriages in women by shooing off bad dreams: you were meant to speak a banishing incantation over a thread that would then be rubbed with pig liver and wrapped around the pregnant woman's abdomen. Other papyri, however, recommend a more eerie version: they interpret dreams as brought by demons, and say they should be destroyed by "cleansing fire," wielded by the goddess Isis in the form of spitting cobras. Four clay cobras were meant to be put into the corners of a bedroom, the spell recited to them, and sleep then attempted, in the comforting belief that the cobras would spit venom at anything that tried to turn up and cause nightmares.
Dreams Could Be Shared By Two People In The Same Bed
One of the oldest arguments about dreams that wee see in ancient texts involves confusion regarding what they denote: are they a product of a person's own thoughts and soul, or born out of a certain place or time? A slightly bizarre permutation of this argument shows up in the (highly unreliable) Greek historian Herodotus, who recounted a bit of urban legend about the invasion of Greece by the Persian emperor Xerxes I, which happened when Herodotus was a child.
Apparently Xerxes was a firm believer in the idea that dreams popped up from places, so when he received a dream ordering him to invade Greece, he ordered his advisor Artabanus to sleep in his bed instead of him, and experience it, too. Artabanus scoffed because he thought dreams were the product of souls, but promptly experienced the dream, with the added threat of metal rods through his eyes if he didn't obey. Artabanus, impressed and likely terrified, supported the invasion, though it seems likely that he also ordered somebody to perform an exorcism on the king's bed.
(Herodotus was inclined to attribute dream prediction to other ancient rulers, too. One of his other famous stories involved Astyages, king of the Medes, who dreamt that his daughter urinated and flooded the entire continent, and knew that it meant her sons would depose him.)
Dreams Were The Product Of The Liver, Or Breezes
Ancient Greek beliefs about sleep and dreams were often slightly odd; the idea of "medical sleep", in which dreams would somehow heal the wounds of the body or give guidance about how to perform medical surgeries, appears to have been at least partially accepted. But there was a bit of disagreement about what on earth dreams were, and how they got into the body.
Plato and Aristotle had a disagreement on the point. Plato believed that dreams originated in the liver (human this time, not pig), which was highly sensitive to the body and its thoughts, and would change its shape and its "sweetness or bitterness" according to what was going on, influencing dreams that could be seen as divination. Aristotle, however, believed that dreams were the result of the fact that the soul left the body when it slept, and could therefore pick up subtle shifts in the air of the bedchamber. If those breezes carried information, it could interpret it, hence predictive dreams. No, none of this explains your dreams about raising an orphaned pink elephant with Prince Harry and Cher. Sorry.
Dream-Demons Could Impregnate Women As They Slept
Early Christian belief in the power of beings that could invade people's minds as they dreamt for their own nefarious purposes persisted all the way through to the Middle Ages. These demons were divided by gender; an incubus was a male one, a succubus a female one. Christian writers like St. Augustine said they were devils come to tempt humanity in their sleep, producing erotic dreams and sinful behavior. The dreams that involved incubi and succubi were debated; they were probably experiences of sleep paralysis, since they're described as "suffocating" and as if one is crushed from above.
From the 12th century onward, according to the medieval historian Maaike van der Lugt, incubi in particular took on a more sinister reputation. They were seen as demons that acquired human form during a woman's dreams through either solidified air or possessing a corpse, and could actually impregnate her using collected sperm from sleeping men. Charming.
Nightmares Were A Result Of The Devil And Too Much Blood
While not all medieval European nightmares were caused by incubi, bad dreams themselves weren't seen as particularly godly. The advice of the famous medieval nun and polymath Hildegard von Bingen to a young priest suffering from nightmares is based around the idea that bad dreams were caused by too much blood and the influence of the Devil.
"Your terrifying dreams," she told the priest, are caused by "bloody humors in conjunction with melancholia": too much blood in the body, she explains, leaves people open to demonic possession, so that they "are suddenly struck with horror." Her sensible recommendation is that he says prayers every night before he sleeps, to drive the Devil out.
Dragon Tongues And Ape Hearts Could Cure Dream Problems
Renaissance thinkers believed that wearing jewels to bed was one easy way to solve the problem of bad dreams. Rubies, coral and diamonds were all suggested at various times as ways to keep out nightmares, as were opals, topaz and emeralds. (If you're thinking that this was likely the invention of an enterprising jeweler, you may be correct, though perhaps being adorned in rubies and diamonds does in fact make people sleep better.) If, however, you couldn't get your hands on any gemstones, there were other practical options: dragon tongue, ape heart and mink blood.
Texts from the early 1600s recommended that bad dreams could be cured by "the tongue or gallbladder of a dragon boiled in wine," rubbing mink's blood on your temples, or putting the heart of an ape under your pillow. (The dragon above comes from the bestiary History Of Four-Footed Beasts And Serpents by Edward Topsell, who made the dragon-tongue recommendation.)
No comment is made on where to find these things, but the last two in particular were meant to induce "exciting" dreams instead of horrible nightmares — which seems extremely unlikely if you're covering your bed in blood and dismembered ape parts, but hey, who am I to judge.