When Charles II assumed the throne of England in 1660, one of the first acts of his government was to ban Samuel Rutherford's masterwork of political theory, Lex, Rex. Condemned as “a book inveighing against monarchie, and laying ground for rebellion,” Lex, Rex was burned in public, and its author was charged with treason, dismissed from his post as rector of the University of Saint Andrews, and placed under house arrest. His colleagues feared he would be executed. Rutherford, though seriously ill, could not have been more calm; he said that “he would willingly dye on the scaffold for that book with a good conscience.” Things never came to that; Rutherford's illness prevented him from appearing before parliament, and he died in March of 1661.

Rutherford was no stranger to controversy; throughout his life, his fervent Puritanism placed him at odds with Scotland's governmental and religious authorities. He graduated from Edinburgh University in 1621; two years later, he was appointed the regent of humanity at his alma mater. In 1627, Rutherford assumed a pulpit in the parish of Anwoth in Galloway; he served there until 1636, when he was deposed on account of his non-conformist religious convictions and exiled to Aberdeen. Two years later, after his exile was lifted, Rutherford returned to Anwoth; shortly thereafter, he was appointed professor of divinity at the University of Saint Andrews. In 1643, he went to London for the Westminster Assembly of Divines; it was here that pleted Lex, Rex.

Lex, Rex begins with Rutherford affirming the classical Christian idea that there is a strong connection between the natural law and scriptural revelation; as he put it, “The Scripture's arguments may be drawn out of the school of nature.” From this concept, Rutherford derived his theory of limited government and constitutionalism—a theory that would eventually draw the fury of his king. For Rutherford, the natural law teaches that man is born free and, consequently, no one is born a ruler by right; “no man bringeth out of the womb with him a sceptre and a crown upon his head,” in his words. By saying this, however, Rutherford does not mean to say that political authority is not ordained by God; on the contrary, God does establish the legitimacy of political offices, but these offices and the powers they wield are to be differentiated from the office holders. Kings, like everyone else, are subject to the laws of nature and Scripture, as well as the positive laws from which they are derived. Kings who act otherwise are tyrants—and tyrants, according to Rutherford, are to be resisted.

Sources: Lex Rex by Samuel Rutherford (Sprinkle Publications, 1982), and Politics, Religion, and the British Revolutions by John Coffey (Cambridge University Press, 1997).