In many of the ancient mystery or mystical schools, symbols were important tools used to help one become more spiritual and to better understand the spiritual world.  Known today primarily as the creator of geometry, Pythagoras was primarily a philosopher and spiritual teacher.  He taught his students to contemplate on various simple geometric forms.  Plato is believed to have done much the same with his students.  The Gnostics also spent time contemplating various symbols.  The most important symbol was a simple cross with four equal length arms, sometime in a circle representing the sun.  
    One place where these Gnostic symbols can be found is in gems that have survived from the early Christian centuries.  These Gnostic gems were often carved with words and elaborate figures.  One of the most common design is of Abraxus riding a chariot.  Abraxus was a solar deity and the Gnostics associated Christ with the Spiritual Sun.  Figures of lions and snakes with lion heads were also common on these gems and represent Spiritual Light.  Members of Gnostic groups are believed to have worn these gems to identify them to other member of the sect they might encounter.  They probably had additional uses such as contemplating the importance and the meaning of the figure on them.