I don't buy either of your premises. Capitalism at its core is voluntary exchange; an entirely voluntary system in which the initiation of violence harms all.
I see you are a true believer in the mythical sort of capitalism that has only ever existed in your imagination. The violence-free capitalist utopia. I read a lot about this capitalism on internet forums, yet strangely I have never read an account of it existing in history.
Remember that capitalism was born around four hundred years ago, a time when violence was much more normal and acceptable than it is today. Capitalism makes much more sense in 1700 than it does in 2015, because violence is becoming less and less legitimate.