User blog comment:Jartsa67/question about souls/@comment-46.12.184.32-20130904201217

I have two ideas about this:

1) Death was wrong.Since he didn't created souls, he probably doesn't have a full picture of the characteristics of souls.

2) Death was right. When demons die, they are so badly damaged that are incapable of sentience.

I dont think the knife damages the soul of the vessel. Bobby stabbed himself with the knife in season 5 and his soul wasn't damaged, since he became a ghost