The document discusses prehistoric medicine and compares it to practices of Australian Aborigines. It notes that prehistoric people performed trephining operations on skulls, as evidenced by healed bone growth. Historians have proposed various theories for why, including drinking vessels or releasing evil spirits. The document also describes how Aborigines used spiritual explanations and natural remedies for illnesses and injuries, treating wounds with clay or animal fat and broken bones with hardened clay casts. Their spiritual explanations involved evil spirits causing illnesses or a person's spirit leaving their body.