Charles Hodge on the Role of Civil Government

Commenting on the Law, more specifically, the fifth commandment, Hodge says --

[T]he Scriptures clearly teach that no human authority is intended to be unlimited.  Such limitation may not be expressed, but is always implied. The command “Thou shalt not kill,” is unlimited in form, yet the Scriptures recognize that homicide may in some cases be not only justifiable but obligatory. The principles which limit the authority of civil government and of its agents are simple and obvious. The first is that governments and magistrates have authority only within their legitimate spheres. As civil government is instituted for the protection of life and property, for the preservation of order, for the punishment of evil doers, and for the praise of those who do well, it has to do only with the conduct, or external acts of men. It cannot concern itself with their opinions, whether scientific, philosophical, or religious. An act of Parliament or of Congress, that Englishmen or Americans should be materialists or idealists, would be an absurdity and a nullity. The magistrate cannot enter our families and assume parental authority, or our churches and teach as a minister. A justice of the peace cannot assume the prerogatives of a governor of a state or of a president of the United States.  Out of his legitimate sphere a magistrate ceases to be a magistrate. (iii. 358-359)