That's a legal principle, not necessarily an ethical or moral principle.

You don't have to look very deep into history to find numerous example of unethical laws. Nor do you have to look much deeper to find laws that are immoral by any rational standpoint.

Obviously there's a lack of concurrence which is obvious both by the number of legal disputes over these matters as well as the wildly varying laws from country to country, some of which remain quite barbaric.

There may or may not be correlation between law and ethics, but I sure as hell wouldn't call them fundamental principles of ethics.