For thousands of years, secret societies are said to have guarded hidden knowledge of otherworldly origin. This knowledge was often revealed only to a select few?from the mystery schools of ancient Egypt, the hidden order of the Magi, to the cryptic writings of the Emerald Tablets. Pythagoras was initiated into the cosmic language of geometry, while the Knights Templar and Freemasons incorporated sacred numbers, mystical patterns, and divine symbols into their art and architecture.