The "free soul" is said to leave the body and journey to the spirit world during sleep, trance-like states, delirium, insanity, and death. The duality is also seen in the healing traditions of Austronesian shamans, where illnesses are regarded as a "soul loss" and thus to heal the sick, one must "return" the "free soul" (which may have been stolen by an evil spirit or got lost in the spirit world) into the body. If the "free soul" can not be returned, the afflicted person dies or goes permanently insane.