The cross is a symbol given to man by the creative imagination of his race's early seers. Its flat crossbar is his ordinary everyday life which he shares with all other men. Its upright bar is his higher spiritual life which he shares with God. The entire figure tells him that crucifixion of his ego is resurrection of his spirit--normally and daily dead in the material life.
-- Notebooks Category 4: Elementary Meditation > Chapter 5: Visualizations, Symbols > # 47