It is a double-edged makeshift to entrust an individual or a group of individuals with the authority to resort to violence. The enticement implied is too tempting for a human being. The men who are to protect the community against violent aggression easily turn into the most dangerous aggressors. They transgress their mandate. They misuse their power for the oppression of those whom they were expected to defend against oppression. The main political problem is how to prevent the police power from becoming tyrannical. This is the meaning of all the struggles for liberty.

Chapter 5: On Some Popular Errors Concerning the Scope and Method of Economics, § 10 : The Concept of a Perfect System of Government - The Ultimate Foundation of Economic Science (1962)