Renaissance term for a primordial life force. Archeus (pronounced “ARK-ee-us”) was first coined by 16th-century German philosopher Paracelsus. He used it to refer to his own concept of a life force that gave life to all other organisms and individuals. Like Paracelsus’s concept of medicine, which he saw as a fight against the invading organism rather than against an imbalance within the body itself, the Archeus idea was based on religious and mystical ideas rather than scientific principles.