Spirit

"Nessarose, is there a difference between a spirit and a soul?"

Nessa smiled at her sister.

"Of course! A spirit is bad, but a soul is good!"

Elphaba smirked.

"Explain the difference."

"Well… a spirit is like a ghost! It possesses people and makes them do unholy things! But a soul is what everyone has! It makes people do good things and earns them a path to the Other Side!"

Elphaba decided she liked spirits better than souls.