Ouroboros
The ouroboros or uroboros is an ancient symbol depicting a serpent or dragon eating its own tail. Originating in ancient Egyptian iconography, the ouroboros entered western tradition via Greek magical tradition and was adopted as a symbol in Gnosticism and Hermeticism and most notably in alchemy. The term derives from οὐροβόρος, from οὐρά, "tail" + βορά, "food", from βιβρώσκω, "I eat". The ouroboros is often interpreted as a symbol for eternal cyclic renewal or a cycle of life, death, and rebirth. The skin-sloughing process of snakes symbolizes the transmigration of souls, the snake biting its own tail is a fertility symbol. The tail of the snake is a phallic symbol, the mouth is a yonic or womb-like symbol.
Historical representations
Ancient Egypt
The first known appearance of the ouroboros motif is in the Enigmatic Book of the Netherworld, an ancient Egyptian funerary text in KV62, the tomb of Tutankhamun, in the 14th century BC. The text concerns the actions of the god Ra and his union with Osiris in the underworld. The ouroboros is depicted twice on the figure: holding their tails in their mouths, one encircling the head and upper chest, the other surrounding the feet of a large figure, which may represent the unified Ra-Osiris. Both serpents are manifestations of the deity Mehen, who in other funerary texts protects Ra in his underworld journey. The whole divine figure represents the beginning and the end of time.The ouroboros appears elsewhere in Egyptian sources, where, like many Egyptian serpent deities, it represents the formless disorder that surrounds the orderly world and is involved in that world's periodic renewal. The symbol persisted in Egypt into Roman times, when it frequently appeared on magical talismans, sometimes in combination with other magical emblems. The 4th-century AD Latin commentator Servius was aware of the Egyptian use of the symbol, noting that the image of a snake biting its tail represents the cyclical nature of the year.
Alchemy and Gnosticism
The famous ouroboros drawing from the early alchemical text, The Chrysopoeia of Cleopatra, probably originally dating to third century Alexandria but first known in a tenth century copy, encloses the words hen to pan, "the all is one". Its black and white halves may perhaps represent a Gnostic duality of existence, analogous to the Taoist yin and yang symbol. The chrysopoeia ouroboros of Cleopatra the Alchemist is one of the oldest images of the ouroboros to be linked with the legendary opus of the alchemists, the philosopher's stone.An aim of alchemists and adepts, described as "individual self-perfection through physical transmutation and spiritual transcendence", was familiar to the alchemist and physician Sir Thomas Browne. It focused on the eternal unity of all things as well as the cycle of birth and death. In his A Letter to a Friend, a medical treatise full of case-histories and witty speculations upon the human condition, he wrote:
In Gnosticism, a serpent biting its tail symbolized eternity and the soul of the world. The Gnostic Pistis Sophia describes the ouroboros as a twelve-part dragon surrounding the world with its tail in its mouth.
A 15th-century alchemical manuscript, The Aurora Consurgens, features the ouroboros, where it is used amongst symbols of the sun, moon, and mercury.
The "world serpent" in mythology
In Norse mythology, the ouroboros appears as the serpent Jörmungandr, one of the three children of Loki and Angrboda, which grew so large that it could encircle the world and grasp its tail in its teeth. In the legends of Ragnar Lodbrok, such as Ragnarssona þáttr, the Geatish king Herraud gives a small lindworm as a gift to his daughter Þóra Town-Hart after which it grows into a large serpent which encircles the girl's bower and bites itself in the tail. The serpent is slain by Ragnar Lodbrok who marries Þóra. Ragnar later has a son with another woman named Kráka and this son is born with the image of a white snake in one eye. This snake encircled the iris and bit itself in the tail, and the son was named Sigurd Snake-in-the-Eye.It is a common belief among indigenous people of the tropical lowlands of South America that waters at the edge of the world-disc are encircled by a snake, often an anaconda, biting its own tail.
Symbol of Birth, death and rebirth
The Ouroboros symbol is a common sight on 17th and 18th century gravestones. Varying from region to region some have legs and even torso like bodies while others are carved in a bracelet like circle. They appear alongside the Hourglass, skulls, bible and cherubs that are so common in depictions of mortality of this era. And like those other symbols they disappeared from gravestones in the 19th century Gothic revival.Connection to Indian thought
In the Aitareya Brahmana, a Vedic text of the early 1st millennium BCE, the nature of the Vedic rituals is compared to "a snake biting its own tail."Ouroboros symbolism has been used to describe the Kundalini. According to the medieval Yoga-kundalini Upanishad, "The divine power, Kundalini, shines like the stem of a young lotus; like a snake, coiled round upon herself she holds her tail in her mouth and lies resting half asleep as the base of the body".
Storl also refers to the ouroboros image in reference to the "cycle of samsara".
Modern references
Jungian psychology
Swiss psychiatrist Carl Jung saw the ouroboros as an archetype and the basic mandala of alchemy. Jung also defined the relationship of the ouroboros to alchemy:The Jungian psychologist Erich Neumann writes of it as a representation of the pre-ego "dawn state", depicting the undifferentiated infancy experience of both mankind and the individual child.
Kekulé's dream
The German organic chemist August Kekulé described the eureka moment when he realized the structure of benzene, after he saw a vision of Ouroboros:I was sitting, writing at my text-book; but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by the repeated visions of the kind, could now distinguish larger structures of manifold conformation: long rows, sometimes more closely fitted together; all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the consequences of the hypothesis.
Cosmos
used the ouroboros to illustrate the various scales of the universe, ranging from 10−20 cm at the tail, up to 1025 cm at the head. Rees stressed "the intimate links between the microworld and the cosmos, symbolised by the ouraborus", as tail and head meet to complete the circle.Armadillo girdled lizard
The genus of the armadillo girdled lizard, Ouroborus cataphractus, takes its name from the animal's defensive posture: curling into a ball and holding its own tail in its mouth.Mathematics and Computer Science
The paradoxical self-referential behavior of algorithms involving recursive or metaprogramming constructs, such as The Meta-circular evaluator, are often explained using the ouroboros as a metaphor.Consider the Fixed-point combinator, expressed through a Symbolic Expression: