The Ouroboros

The Ouroboros — the serpent devouring its own tail — is one of the oldest alchemical emblems, appearing in the Chrysopoeia of Cleopatra the Alchemist (c. 3rd century) with the inscription hen to pan ('the All is One'). It signifies the closed, self-sustaining nature of the alchemical opus: the end product feeds back into the beginning, and the Work is never truly finished because completion initiates a new cycle of dissolution. The Britannica account traces the symbol from Hellenistic Egypt through medieval European manuscripts, where it encircles the entire Magnum Opus as a reminder that the Stone, once achieved, must be multiplied — perfection is iterative, not terminal.