How do we prevent violence? I think the only way is by following the advice of the elder in the legend: by feeding the good wolf.
This is very true, we all have an "evil inclination" that must be dealt with - however our nature is intended to be good and harmless. There are rare instances where violence is actually good (a good wolf still has TEETH!), defending a friend or loved one or self, but the greater response is non-violence and it takes a very special mindset for that to happen.
!BBH