Ceremonial Magick: "#Goetia: The Lesser Key of Solomon: The Initiated Interpretation of #Ceremonial #Magic," by S.L. MacGregor Mathers and Aleister Crowley. A complete book of magickal symbols and sigils, by two of the most prominent and influential occultists of all time. The "Lesser Key" contains the magickal sigils of the 72 "Goetia," spirits that can be called upon by the Adept to perform actions on the astral plane.
Union of Opposites: The Caduceus Consider the snakes as they wind around the staff of Mercury. They are in eternal conflict. They are the opposites. Life & Death. Science & Art. Any pair of opposites you can imagine. They cannot unite at their own level, as Jung described because they are in eternal conflict.