"people are naturally at peace" That's blatantly incorrect - mainly because of the use of the world "people." While the vast majority of humanity is peaceful,

"people are naturally at peace" That's blatantly incorrect - mainly because of the use of the world "people." While the vast majority of humanity is peaceful, a substantial minority of people are naturally inclined towards violence. That element exists in every population, and the exact percentage seems to change depending on the culture, area, etc. One goal of civilization is to suppress and/or redirect those people's behaviors. In fact, you could probably argue that civilization is the continuing attempt to handle that segment of humanity. If you look at "the old days" you'd see a surprising amount of low-level violence directed towards pretty much everyone. Occasionally that segment of the population takes over and you get a warrior culture. Occasionally that segment takes over and you have a riot/uprising/rebellion. Normally civilizations try to control them via police, or conflict, or sports. One problem in civilization is balancing the need for those people without having those people take over (a major continuing problem what used to be called the Third World).