The caduceus from Greek κηρύκειον kērukeion "herald's staff"is the staff carried by Hermes Trismegistus in Egyptian mythology and Hermes in Greek mythology. The same staff was also borne by heralds in general, for example by Iris, the messenger of Hera. It is a short staff entwined by two serpents, sometimes surmounted by wings. In Roman iconography, it was often depicted being carried in the left hand of Mercury, the messenger of the gods, guide of the dead and protector of merchants, shepherds, gamblers, liars, and thieves.
Some accounts suggest that the oldest known imagery of the caduceus
have their roots in a Mesopotamian origin with the Sumerian god
Ningishzida whose symbol, a staff with two snakes intertwined around it,
dates back to 4000 B.C. to 3000 B.C.
As a symbolic object, it
represents Hermes (or the Roman Mercury), and by extension trades,
occupations, or undertakings associated with the god. In later
Antiquity, the caduceus provided the basis for the astrological symbol
representing the planet Mercury. Thus, through its use in astrology and
alchemy, it has come to denote the elemental metal of the same name. It
is said the wand would wake the sleeping and send the awake to sleep. If
applied to the dying, their death was gentle; if applied to the dead,
they returned to life.
The Rod of Asclepius takes its name from
the god Asclepius, a deity associated with healing and medicinal arts
in Greek mythology. Asclepius's attributes, the snake and the staff,
sometimes depicted separately in antiquity, are combined in this symbol.
The most famous temple of Asclepius was at Epidaurus in north-eastern
Peloponnese. Another famous healing temple (or asclepieion) was located
on the island of Kos, where Hippocrates, the legendary "father of
medicine", may have begun his career. Other asclepieia were situated in
Trikala, Gortys (in Arcadia), and Pergamum in Asia.
In honor of
Asclepius, a particular type of non-venomous snake was often used in
healing rituals, and these snakes – the Aesculapian Snakes – crawled
around freely on the floor in dormitories where the sick and injured
slept. These snakes were introduced at the founding of each new temple
of Asclepius throughout the classical world. From about 300 BC onwards,
the cult of Asclepius grew very popular and pilgrims flocked to his
healing temples (Asclepieia) to be cured of their ills. Ritual
purification would be followed by offerings or sacrifices to the god
(according to means), and the supplicant would then spend the night in
the holiest part of the sanctuary – the abaton (or adyton). Any dreams
or visions would be reported to a priest who would prescribe the
appropriate therapy by a process of interpretation.Some healing temples
also used sacred dogs to lick the wounds of sick petitioners.
The original Hippocratic Oath began with the invocation "I swear by
Apollo the Physician and by Asclepius and by Hygieia and Panacea and by
all the gods ..."
The serpent and the staff appear to have been
separate symbols that were combined at some point in the development of
the Asclepian cult.The significance of the serpent has been interpreted
in many ways; sometimes the shedding of skin and renewal is emphasized
as symbolizing rejuvenation,while other assessments center on the
serpent as a symbol that unites and expresses the dual nature of the
work of the physician, who deals with life and death, sickness and
health.The ambiguity of the serpent as a symbol, and the contradictions
it is thought to represent, reflect the ambiguity of the use of
drugs,which can help or harm, as reflected in the meaning of the term
pharmakon, which meant "drug", "medicine" and "poison" in ancient
Greek.Products deriving from the bodies of snakes were known to have
medicinal properties in ancient times, and in ancient Greece, at least
some were aware that snake venom that might be fatal if it entered the
bloodstream could often be imbibed. Snake venom appears to have been
'prescribed' in some cases as a form of therapy.