Tell me, in your "fantasy-world", why do you think that everyone will abide by that law?
Because those that do not will:
a) pay restitution to those who they have harmed (Financial incentive)
b) be ostracized (social, and to a lesser extent, financial incentive) or
c) be killed in the commission of an aggressive act.
What makes you think those will be the laws? Communities gather like minded individuals, and perhaps the community you live in will slowly evolve into a pirate enclave, for all you know.
Keep dreaming about your "fantasy-world". You could write a fictional book about your ideal society, and most people would stop reading it halfway through because it does not realistically model human behavior. It would have the feel of a naive writer creating fiction to masquerade as his propaganda for an implausible society.