Caduceus as a symbol of medicine why he chose a herald's wand as a symbol, making it clear that he chose it as a symbol of prudence. This same passage was also earlier referenced by Engle in refuting Garrison's claim. Engle and Friedlander are not the only ones to have noted that the use of the Caduceus by Caius had nothing to do with supposed medical symbolism; as indicated in a publication produced by the Royal College of Physicians itself: "[...] by introducing the caduceus into the ceremony of the College of Physicians, Caius unintentionally added to the confusion between the two emblems for later times,
Caduceus 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, alchemy, and astronomy it has come to denote the planet and elemental metal of the same name. It is said