Souls are a powerful energy source. Famine consumed them to strengthen himself,<ref name="five14">[[5.14 My Bloody Valentine]]</ref> demons bargain for them, and even angels have traded in them.
When [[Castiel]] rescues [[Sam]] from [[Lucifer's Cage]], his soul remains trapped in the cage until Death retrieves it for him. Without his soul, Sam feels no empathy, guilt or compassion. He is not evil, but rather lacks any moral compass. While he continues to have physical needs for food and sex, he doesn't sleep, and has a high tolerance for pain.
==After Death==