“A contract, the conditions whereof are violated by neither side, cannot be dissolved but by the joint consent of both; and in buying and selling, and in all contracts unviolated, the sole will of neither side can violate the contract; of this speaketh the law. We hold that the law saith with us that vassals lose their farm if they pay not what is due. Now what are kings but vassals to the state, who, if they turn tyrants, fall from their right?” – Samuel Rutherford, “Lex Rex” (in A. S. P. Woodhouse, Puritanism & Liberty)