Let's talk about evil.  Now, the definition of evil, is morally wrong or bad, immoral or wicked.  Now, no matter how much we all like to believe all of these things to be true, I believe that evil does not exist.  In my mind, evil is in the eye of the beholder, and a measure of selfishness.  Let me break it down for you.  Evil, can be interpreted differently by different people.  Something that my neighbor does may be seen as evil by my other neighbor, but not evil by me at the same time.  I may perceive it as a bad or immoral act, but to call something purely evil, is to say that the only intention of doing this act, was to inflict harm on another for my own amusement.  Also, the person who you may think had done an evil act, may not think it was evil at all.  If somebody has to kill somebody else for whatever reason, people may view it as evil, but the murderer may not. My second point, is that evil is only a measure of selfishness.  Think of it this way.  If somebody is to commit an act, and they were to do it purely selfishly, then the people around that person would lesser of this individual.  If somebody were to kill another person, it has to be for a reason.  They would only commit this crime for a certain gain that would prove to be beneficial to him or her.  People don't do something just for the sake of it, and more often that not, it is in their own self interest.  The more the action is considered selfish, the more the action will be considered evil.  One more thing to add, is that people who have gone mad do not fall under the category in my opinion, because they cannot help their condition.