Samuel Rutherford's Due Right of Presbyteries is over 800 pages in length. Rutherford here deals with church membership, separation from the visible church, the civil magistrate and religion, communion among churches, the errors of the independents (specifically in New England) and much more.

This could be considered the Lex Rex of church government -- another exceedingly rare masterpiece of Presbyterianism!

Characterized by Walker as sweeping "over a wider field than most. Most essential points which Gillespie has barely touched, Rutherford carefully considers; as, for instance, the nature of the visible church as such, and its constituent elements. Even in the Erastian controversy he is a necessary supplement to his great contemporary. It is something to me altogether amazing, the mass of thinking about Church questions you have in those writings."

James Bannerman, in his Church of Christ calls this a "very learned and elaborate treatise."

Here is a sample of Samuel Rutherford's writing:

"A private subtraction and separation from the Ministry of a known wolf and seducer,... this the Law of nature will warrant... as Parker saith from Saravia, 'it is lawful to use that blameless and just defence, if the bad church-guide cannot be deposed.' So the son may save himself by a just defense in fleeing from his mad father, or his distracted friend coming to kill him. Now this defense is not an authoritative act, nor [a] judicial act of authority, but a natural act that is common to any private person, yea to all without the true Church as well as within to take that care in extreme necessity, for the safety of their souls, that they would do for the safety of their bodies" (1642, cited in The Original Covenanter and Contending Witness magazine [http://www.covenanter.org/]).