According to John Adams, the third great stage of English intellectual confrontation with tyranny took place in the years around the Glorious Revolution of 1688. Then, the important writers included John Locke and Algernon Sidney. John Adams, “A Defence of the Constitutions of the United States of America,” vol. 3 (Philadelphia: 1797), Page 211. Thomas Jefferson wrote that the sources of the Declaration of Independence included “the elementary books of public right, as Aristotle, Cicero, Locke, Sidney, &c.” Letter to Henry Lee, May 8, 1825.

Algernon Sidney was a descendant of Harry Percy, the “Hotspur” of Shakespeare’s “Richard II” and “Henry IV, Part 1.” Sidney fought bravely with the parliamentary forces during the English Civil War of 1642–1646, and lived in exile in France after the Restoration of the Stuart monarchy in 1660. Starting in 1681, when fears over the Stuarts’ totalitarian ambitions grew intense, Sidney, who had returned to England, worked assiduously to organize the overthrow of the Stuarts. In 1683, Sidney was arrested for treason. He was convicted in a trial that was later regarded as a travesty of justice, not allowed to see the indictment against him. Executed on Dec. 7, 1683, Sidney was venerated by the Americans as one of the greatest martyrs of liberty. The trial is reported in Samuel March Phillips, 2 State Trials 87–117 (1826).

Sidney’s “Discourses Concerning Government” could not have been published while the Stuarts sat on the throne, but the freer atmosphere after the Glorious Revolution allowed posthumous publication.

Like Locke’s “First Treatise,” Sidney’s “Discourses Concerning Government” was a refutation of Robert Filmer’s “Patriarcha,” which had argued that all kings share in the dominion God granted to Adam, and that any resistance to a king, no matter how tyrannical he might be, is sinful. Filmer did not merely seek to restore the Dark Ages theory that the king was God’s anointed. Even under the Dark Ages standard, the king was required to rule according to the law and customs of the nation. Filmer claimed that the king was free of every constraint.

Sidney tore into “Patriarcha” line by line.

By now, the Jewish heroes who had overthrown bad governments were so well-known — now that almost every home contained an English-language Bible — that Sidney could reel off the heroes without need for explanation: “Moses, Othniel, Ehud, Barak, Gideon, Samson, Jephthah, Samuel, David, Jehu, the Maccabees, and others.” Such men were “perpetually renowned for having led the people by extraordinary ways … to recover their liberties, and avenge injuries received from foreign or domestick tyrants.”

Some people feared forcible resistance to tyranny, because it would lead to chaos. Sidney argued the opposite. As one section’s title summarized, “Popular Governments are less subject to Civil Disorders than Monarchies; manage them more ably, and more easily recover out of them.” Hence, a violent revolution to instill a popular government would, in the long run, lead to more stability and less violence.

Sidney was a militia enthusiast, using many examples from ancient Greece and Rome, and from more recent European history, to show that a militia fighting for its freedom would defeat mercenaries interested merely in pay.

On the duty of individuals and nations to use force, when necessary, to protect their own interests, Sidney coined the English version of the epigram “God helps those who help themselves.” (The original is in Greek, in Aesop’s fable “Hercules and the Waggoner.”)

Without a natural right of self-defense, society itself would cease to exist:

Nay, all laws must fall, human societies that subsist by them must be dissolved, and all innocent persons be exposed to the violence of most wicked, if men might not justly defend themselves against injustice by their own natural right, when the ways prescribed by public authority cannot be taken.

From the right of personal self-defense against a criminal, a collective right of self-defense against criminal governments necessarily followed. To be subject to a tyrant was little different from being under the power of a pirate. Philo of Alexandria, Cicero and Augustine had said the same.

Thus, “those arms were just and pious that were necessary, and necessary when there was no hope of safety by any other way. This is the voice of mankind, and is disliked only” by princes who fear deserved punishments, and their flatterers and servants who share the princes’ guilt.

The necessary corollary of the right of self-defense against tyrants was the possession of arms: “he is a fool who knows not that swords were given to men, that none might be slaves, but such as know not how to use them.”

England’s situation in the 1680s worried Sidney, for the old checks and balances were vanishing: “That which might have easily been performed when the people were armed, and had a great, strong, virtuous and powerful nobility to lead them, is made difficult, now they are disarmed, and that nobility abolished.” (Noble ranks still existed; Sidney meant that the nobles had much less ability to check a lawless king.)

The English were not obliged to live under the same system of government as their ancestors, because human understanding had increased. So “if it be lawful for us by the use of that understanding to build houses, ships, and forts better than our ancestors, to make such arms as are most fit for our defence, and to invent printing, with an infinite number of other arts beneficial to mankind, why have we not the same right in matters of government …”

While parts of the New Testament (especially, Romans 13) had urged submission to government, “those precepts were merely temporary, and directed to the person of the apostles, who were armed only with the sword of the spirit; that the primitive Christians used prayers and tears only no longer than whilst they had no other arms.” By becoming Christians, men “had not lost the rights belonging to all mankind.” So “when God had put means into their hands of defending themselves,” then “the Christian valour soon became no less famous and remarkable than that of the pagans.”

Sidney disputed Filmer’s claim that God “caused some to be born with crowns upon their heads, and all others with saddles upon their backs.” A few days before Jefferson died on July 4, 1826, the 50th anniversary of the Declaration of Independence, he wrote his final letter, which echoed Sidney’s words from a century and a half before:

All eyes are opened, or opening, to the rights of man. The general spread of the light of science has already laid open to every view the palpable truth, that the mass of mankind has not been born with saddles on their backs, nor a favored few booted and spurred, ready to ride them legitimately, by the grace of God.

Letter to Roger Weightman, June 24, 1826.

Together, Sidney and Locke showed that the right of resistance is inseparable from the right of religious freedom. The early Protestant and Catholic resistance theorists had been passionately interested in their own religious freedom, and intolerant of the freedom of other religions. Locke and Sidney advanced the right of resistance to mean the right of religious freedom for everyone. Because no one could use the power of the state to force a religion on someone else, there was no need to fear or suppress anyone else’s religion.

It would take a while for Locke’s and Sidney’s ideas to be fully accepted in England. Their true fruition, however, would come in the United States, where they are embodied in the Declaration of Independence, the First and Second Amendments, and the American way of life.

This essay is adapted from my forthcoming book “The Morality of Self-Defense and Military Action: The Judeo-Christian Tradition.”