The ethereal soul refers to the conscious mental activities of human including sensibility, awareness, intelligence and comprehension, which are governed by the liver. Upon birth, human being is capable of sensation, attention and consciousness. These capabilities develop with growth in the environment for the acquisition of intelligence and comprehension, all falling into the domain of ethereal soul. When the liver stores abundant blood, the ethereal soul remains intact and consciousness is sharp. Otherwise, abnormal mental consciousness may occur with such symptoms as hallucination, sleep walking or sleep disorders.