1. Humans are inherently *capable* of violence and evil, yes because what drives human behavior (mostly) is incentives. If you do not strongly disincentivize violence, it's a virtual certainty that *some* humans will use it against regular people, and society will be at the mercy of those most willing to use it. Libertarianism fails to disincentivize violence against the innocent. Communism fails to incentivize wealth creation among the capable, and when resources are scarce, violence ensues. They both ignore basic, fundamental obvious facets of human nature. 2. There may be other options, but what's not optional is the credible threat of retributive violence should you commit violence against someone else. Again, feel free to live in the wild west and hunt people with your posse if you prefer, but most people are going to want to outsource that task.