"There is a strange idea connected to the concept of a "shadow self" proposed by Jung. He suggested, that it is required to be a complete person, to be whole. That you need to understand it, accept it. However that is not the idea I am talking about. I once heard a curious suggestion: you are unable to truly be good without understanding your shadow self. You are unable to truly strive for good until you fully understood your own capacity for evil. Problem with stuff like this is you can never actually ask for any proof to support the idea."