Caduceus Symbol: Hermes' Staff, Alchemy and the Two Serpents

The caduceus is the staff of Hermes, the Greek messenger god known to the Romans as Mercury: a rod entwined by two serpents facing each other, usually crowned with a pair of wings. In antiquity it was the herald's wand, a sign of safe passage, negotiation and commerce. Because Hermes was identified with Hermes Trismegistus, the legendary founder of alchemy and Hermetic philosophy, the caduceus became one of the chief emblems of the alchemical Mercurius and of the union of opposites. Its widespread use as a medical badge is a modern confusion with the single-serpent rod of Asclepius.

The Herald's Staff of Hermes§

In archaic and classical Greece, a herald (kēryx) carried a staff called the kērykeion, from which the Latin caduceus is derived. Heralds carried messages between cities and armies, announced truces and proclaimed public business, and their persons were treated as inviolable; the staff marked that protected status. Hermes, the herald of the gods, carries it in countless vase paintings. Early representations often show a simple rod topped by an open loop over a crescent, a form that resembles a figure of eight; in time the two ends of the loop were drawn as serpents' heads, and the familiar intertwined snakes appeared.

The staff was also a magic wand. In the Odyssey, Hermes uses his rod to charm men's eyes to sleep or wake them, and in the last book he leads the souls of the dead suitors down to Hades with it, in his role as psychopompos, guide of souls. The Homeric Hymn to Hermes tells how Apollo, reconciled with his thieving younger brother, gave him a golden wand of wealth and prosperity. The Latin writer Hyginus later preserved an explanatory story: Mercury found two snakes fighting, laid his staff between them, and they wound around it in peace, so that the caduceus became a sign of reconciliation. Like many such tales it probably explains an existing image rather than recording its origin. The Greek religious background is described in Greek religion and the mysteries.

Ancient Precursors and Roman Mercury§

Images of two serpents twined around a staff are older than Greek art. A carved green steatite libation vase made for Gudea, ruler of Lagash in southern Mesopotamia around 2100 BCE and now in the Louvre, shows two copulating serpents coiled around an axis, flanked by winged guardian creatures; the serpents are an emblem of Ningishzida, Gudea's personal god, a deity connected with vegetation and the underworld. Scholars often cite it as a parallel, though a direct line of descent to the Greek herald's staff is not established.

In the Roman world the caduceus belonged to Mercury, god of merchants, travellers, eloquence and luck, and it appears constantly on coins, gems, shop signs and lamps. Wings, added to the staff in Hellenistic and Roman art, matched the god's winged sandals and hat and stressed his speed. The staff stood for commerce and concord: Roman coins pair it with clasped hands, cornucopias and personifications of Peace and Good Fortune. This commercial meaning survives in modern emblems of trade, customs services and postal administrations.

Hermes Trismegistus and the Hermetic Caduceus§

In Hellenistic Egypt, Hermes was identified with the Egyptian god of wisdom, Thoth, and the composite figure of Hermes Trismegistus, "thrice-greatest Hermes", became the reputed author of works on astrology, magic, alchemy and philosophy. When the Corpus Hermeticum was translated into Latin by Marsilio Ficino in 1463 and published in 1471, the Renaissance revived the image of Hermes as a primordial sage. The caduceus, his attribute, became shorthand for Hermetic wisdom; the story of this figure is told in Hermes Trismegistus.

Renaissance humanists treated the caduceus as an emblem of eloquence, prudence and the reconciling power of reason. Andrea Alciato's Emblemata (first published in 1531), the founding work of the emblem-book genre, includes emblems built on Mercury and his staff. The Basel printer Johann Froben adopted as his device a staff wound with two serpents and crowned by a dove, combining the prudence of the serpent with the simplicity of the dove from Matthew 10; his books, including the works of Erasmus, carried the image across Europe. Through such uses the two-serpent staff became associated with learning and publishing, a link that later contributed to its medical career.

The Caduceus in Alchemy: Mercurius and the Two Serpents§

Alchemy was called the Hermetic art, and its central agent was Mercurius, at once the metal quicksilver, the planet Mercury and the elusive spirit of transformation hidden in matter. Alchemical texts describe Mercurius as double, both male and female, volatile and fixed, poison and medicine, and the caduceus, held by Mercury in many engravings, was read as a picture of this doubleness. The astronomical and alchemical sign of Mercury, ☿, is often interpreted as a stylised caduceus, though its graphic origin in late antique manuscripts is uncertain. The wider vocabulary of these signs is set out in alchemical symbols.

In alchemical interpretation the two serpents stand for the paired principles of the work: sulphur and mercury, the hot and dry "male" principle and the cold and moist "female" principle, or the fixed and the volatile, which must be separated and then reunited. The rod between them is the axis or medium of their union, and the wings above signify volatilisation, the rising of spirit. The image thus expresses the formula solve et coagula, "dissolve and coagulate", and the alchemical marriage that produces the philosophers' stone, the theme of the Rebis, the alchemical androgyne. Two serpents or dragons, one winged and one wingless, biting each other's tails, form a related emblem, akin to the single ouroboros.

Writers of the sixteenth and seventeenth centuries, including followers of Paracelsus, also used the caduceus as a sign of the Hermetic physician, who healed through knowledge of nature's hidden correspondences. In the twentieth century C. G. Jung, in Psychology and Alchemy and later essays on "the spirit Mercurius", interpreted the caduceus as a symbol of the reconciliation of psychic opposites, a reading that has strongly shaped modern popular understanding of the image.

Caduceus or Rod of Asclepius? The Medical Confusion§

The traditional symbol of medicine is not the caduceus but the rod of Asclepius: a rough wooden staff with a single serpent and no wings, held by the Greek healing god Asclepius in his cult statues. Snakes were kept in his sanctuaries, such as Epidaurus, and were associated with renewal because they shed their skin. Hermes, by contrast, was the god of merchants, thieves and messengers, and his staff had no particular connection with healing in antiquity.

The confusion grew from several sources: the Renaissance association of the caduceus with Hermetic medicine and with learned printers, its use by nineteenth-century medical publishers, and above all its adoption by American institutions. The United States Marine Hospital Service used a caduceus in its seal from the 1870s, and in 1902 the Medical Department of the US Army adopted it on uniforms. Walter Friedlander's history The Golden Wand of Medicine traces these decisions in detail. Today the World Health Organization, the American Medical Association and many national medical bodies use the rod of Asclepius, while the caduceus remains common in commercial and American health-care logos, a mismatch that historians of medicine often point out.

Modern Esoteric Readings: Lévi, the Golden Dawn and Kundalini§

Nineteenth-century occultists made the caduceus a key to their systems. In Eliphas Lévi's famous drawing of Baphomet (1856), a caduceus rises from the figure's lap, signifying the balance of opposing forces that Lévi called the great magical agent; see Eliphas Lévi. In the teaching papers of the Hermetic Order of the Golden Dawn, the caduceus was mapped onto the Tree of Life and the three "mother letters" of the Hebrew alphabet, the wings and serpents corresponding to the paths and sephiroth.

Theosophical and later New Age writers compared the two serpents with the iḍā and piṅgalā channels that, in some yoga texts, wind around the central suṣumnā along the spine, and the rising wings with the awakened kuṇḍalinī. This comparison is a modern synthesis, not an ancient Greek or Indian teaching, but it has become widespread in modern esoteric literature; the Indian sources are described in nadis, prana and the subtle body. Comparisons of the caduceus with the double helix of DNA are more recent still and belong to popular symbolism rather than history.

Frequently asked questions§

What does the caduceus symbolise?§

In antiquity it was the staff of heralds and of Hermes, signifying safe conduct, negotiation, commerce and peace. In alchemy and Hermeticism it came to signify the union of opposing principles, especially sulphur and mercury, and the transforming spirit Mercurius.

What is the difference between the caduceus and the rod of Asclepius?§

The caduceus has two serpents and usually wings and belongs to Hermes. The rod of Asclepius has a single serpent on a plain staff and belongs to the healing god Asclepius, which makes it the historically correct symbol of medicine.

Why is the caduceus associated with alchemy?§

Alchemy was known as the Hermetic art after its legendary founder Hermes Trismegistus, and its central substance was mercury, named after the god who carried the caduceus. Alchemists therefore read the staff's two serpents as the paired principles whose union produces the philosophers' stone.

Sources and further reading§

• The Golden Wand of Medicine: A History of the Caduceus Symbol in Medicine — Walter J. Friedlander, 1992
• Hermes the Thief: The Evolution of a Myth — Norman O. Brown, 1947
• Hesiod, the Homeric Hymns and Homerica — Hugh G. Evelyn-White, 1914
• The Egyptian Hermes — Garth Fowden, 1986
• A Dictionary of Alchemical Imagery — Lyndy Abraham, 1998
• Psychology and Alchemy — C. G. Jung, 1944
• Emblemata — Andrea Alciato, 1531