Rating Evil

Do you think you can rate evil? Is someone who kills 1 person (and I’m not talking about self defense or other understandable situations but murder because they enjoy it or think it’s their right to do so) less evil than someone who kills 10? And is that someone a better person than someone who kills 100? Is one more or less excusable than the other?

And do you think when we talk about the past societal norms and understanding of other people back then should play a factor in rating someone’s evil? Like a few 100 years ago women were thought to be less than a man so does that make crimes against them back then more acceptable than it would be today?

Or do you think that someone who is willing and able to commit one act of evil is no better than someone who is willing to continue committing them?