A Snake is one of the symbols of Athene, the goddess of wisdom.
A:sculapius, god of medicine and son of Apollo, carries a staff encircled by a serpent symbolising healing, the renewing power of life.
Hippocrates is given the same symbol. Hygeia, the goddess of health, holds a serpent in her hand. Vishnu, the preserver of the Hindu Trimurti, sleeps on the World Serpent's body.
The Serpent is depicted coiled about the Egg of the World.
The Cross is often entwined by the serpent as a symbol of spiritual re-birth.
"In the Biblical narrative the sexual instinct and the beginning of culture as symbolised by the tree of knowledge are closely associated. According to rabbinical traditions the serpent is the symbol of the sexual passion."1
Conceived of as the manifestation of the Life Principle it symbolises wisdom, power, creation. In the negative or evil sense it is the deadly reptile of materialism and sensuality. It was the serpent in this latter aspect that brought about the expulsion of Adam and Eve from the Garden of Eden.
"The snake in paradise is usually considered feminine as the seductive principle in woman, and is represented as feminine by the old artists, although properly the snake has a phallic meaning.2
1 Jastrow's Religion of Babylonia and Assyria.
2Jung's Psychology of the Unconscious, p. 110.
