I have always loved Symbolism and feel that if we try to understand the many symbols that are used within our culture we will have a much better grasp of the meaning implied.
Symbolism actually began as the earliest form of writing, which would have been in pictures that illustrated the concept of the writer. For a better understanding of this please Google the Sumerian and Egyptian civilizations and look at their cunniform writing and hieroglyphics.
In the 1980s I had the opportunity to visit and to climb most of the Mayan Temples in Mexico and Central America. Images of the snake were everywhere on their petraglyphs. In fact, all ancient peoples reveared the snake as holy and regenerative as the snake is ever re-born as it sheds its skin. When resting it will often curl up into a figure eight which is the symbol for immortality.
Before Christianity lamblasted the poor snake and made it stand for evil, it was the symbol for all spiritual rebirth and also the symbol for woman - who gave birth to all; hence Mother Earth, Mother Mary son of God (used in the Catholic rosary, and so forth.
The snake also symbolized great wisdom - this is evident as all ancient rulers had staff that were shaped like snakes.
I have a much more detailed account of how I use symbols in my art at my new website = www.missnancysart.com
P;ease feel free to check it out.