Obviously a huge percentage of the population is capable of evil depending on your definition of evil. I think setting the line at aggressive violence is about right. Violence when not acting in defense of oneself is wrong. Governments are the only entities with monopolies on violence (thats an Obama quote), and you have to frame any pro-government argument as being a "necessary evil."

The conversation about what is evil or what isn't is a boring one. The relevant conversation should be about how incentives affect aggressive behavior.