 In the history of Chinese writing, characters for "po" "lunar brightness" appeared before those for "hun" "soul; spirit".The spiritual "hun" and "po" "dual souls" are first recorded in Warring States period (475–221 BCE) seal script characters.The lunar "po" or "moon's brightness" appears in both Zhou dynasty (1045–256 BCE) Bronzeware script and oracle bone script, but not in Shang dynasty (ca.