This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
...nt fall into three broad categories, all of them involving the issues of physical force and the protection of men’s rights: the police, to protect men from criminals — the armed services, to
protect men from foreign invaders — the law courts, to settle disputes among men according to objective laws.
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These three categories involve many corollary and derivative issues
— and their implementation in practice, in the form of specific legislation, is enormously complex. It belongs to the field of a special science: the philosophy of law. Many errors and many d...