The Ouroboros (Greek Ουροβόρος, from ουροβόρος όφις "tail-devouring snake", also spelled Ourorboros, Oroborus, Uroboros or Uroborus, in English pronounced /ʊˈrɒbɔrɔs/ or /ˌjʊəroʊˈbɒrəs/), is an ancient symbol depicting a serpent or dragon swallowing its own tail and forming a circle.
The Ouroboros often represents self-reflexivity or cyclicality, especially in the sense of something constantly re-creating itself, the eternal return, and other things perceived as cycles that begin anew as soon as they end (See Phoenix (mythology)). It can also represent the idea of primordial unity related to something existing in or persisting from the beginning with such force or qualities it cannot be extinguished. The ouroboros has been important in religious and mythological symbolism, but has also been frequently used in alchemical illustrations, where it symbolizes the circular nature of the alchemist's opus. It is also often associated with Gnosticism, and Hermeticism.
Carl Jung interpreted the Ouroboros as having an archetypical significance to the human psyche. 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.
Plato described a self-eating, circular being as the first living thing in the universe—an immortal, perfectly constructed animal.
"Coiled dragon" forms have been attributed to the Hongshan culture (4700 BC to 2900 BC). One in particular, in the shape of a complete circle, was found on the chest of the deceased.
The notion of a serpent or dragon eating its own tail can be traced back to Ancient Egypt, circa 1600 BC. From ancient Egypt it passed to Phoenicia and then to the Greek philosophers, who gave it the name Ouroboros ("tail-devourer").
In Gnosticism, this serpent symbolized eternity and the soul of the world.
Christianity adopted the Ouroboros as symbols of the limited confines of the material world (that there is an "outside" being implied by the demarcation of an inside), and the self-consuming transitory nature of a mere "worldly existence" of this world, following in the footsteps of the preacher in Ecclesiastes 3:9-14. G. K. Chesterton, in The Everlasting Man, uses it as a symbol of the circular and self-defeating nature of pantheistic mysticism and of most modern philosophy.
The famous Ouroboros drawing from the early alchemical text The Chrysopoeia of Cleopatra dating to 2nd century Alexandria encloses the words hen to pan, "one is the all". Its black and white halves represent the Gnostic duality of existence.
As a symbol of the eternal unity of all things, the cycle of birth and death from which the alchemist sought release and liberation, it was familiar to the alchemist/physician Sir Thomas Browne. In his A letter to a friend, a medical treatise full of case-histories and witty speculations upon the human condition, he wrote of it:
It is also alluded to at the conclusion of Browne's The Garden of Cyrus (1658) as a symbol of the circular nature and Unity of the two Discourses:
Snakes are sacred animals in many West African religions. The demi-god Aidophedo uses the image of a serpent biting its own tail. The Ouroboros is also seen in fon or dahomean iconography as well as in yoruba imagery as Oshunmare.
The organic chemist August Kekulé claimed that a ring in the shape of Ouroboros that he saw in a dream inspired him in his discovery of the structure of benzene. As noted by Carl Jung, this might be an instance of cryptomnesia.