Without hurting anybody, we all tend to laugh at others' discomfort. When someone slips on a banana skin and falls it's funny.
When you dream, you dialogue with aspects of yourself that normally are not with you in the daytime and you discover that you know a great deal more than you thought you did.
I think that we all know what evil is. We have a sense of what's evil, and certainly killing innocent people is evil. We're less sure about what is good. There's sort of good, good enough, could be better - but absolute good is a little harder to define.