Algernon Sidney and John Locke: How Two Men Answered Filmer and Armed a Revolution

They Executed Him for a Book Nobody Had Read

On the twenty-first of November, 1683, a sixty-year-old man stood at the bar of the Court of King’s Bench charged with high treason, without counsel, because English law did not permit a man accused of treason to have any. The crown had one witness to the plot, and the law required two. So the prosecution reached for the manuscript its officers had carried out of his study that summer — long, unfinished, unpublished, read by almost no one on earth. The Lord Chief Justice, George Jeffreys, instructed the jury in three words of Latin. Scribere est agere. To write is to act. Two weeks later they cut off Algernon Sidney’s head on Tower Hill for a book the crown never proved anyone had circulated.

That same autumn, another Englishman was living in Amsterdam under the assumed name of Doctor van der Linden, in poor health, fifty-one years old, with the English government asking after him. John Locke had been the confidential adviser to the leader of the Exclusion movement, and when that movement collapsed and its leaders began going to the block, his position was not survivable. He stayed abroad more than five years. The manuscript he carried into exile was published anonymously at the end of 1689, and he admitted the authorship only in a codicil to his will.

Both men were writing against the same dead opponent. Sir Robert Filmer had died in 1653, but Patriarcha was published in 1680, in the middle of the Exclusion Crisis, and it made a dead man’s book into a live weapon. This episode states Filmer’s case at full strength before answering it, because an argument answered in its weakest form has not been answered at all — and his hard question has never entirely gone away. When, exactly, did you consent? Where is this original agreement? Produce it. You were born into a country, under laws written before you existed, enforced by a government you never chose, and you did not sign anything.

The hour does not stop at the answers. There is a reckoning owed for each man, and the second is harder by a wide margin. Sidney took secret money from the French ambassador while writing against arbitrary power. Locke held shares in the Royal African Company and, as secretary to the Lords Proprietors, was involved with versions of a colonial constitution declaring that every freeman of Carolina should have absolute power over his slaves — a gap not merely between a philosopher’s words and his conduct, but between what Locke himself wrote about slavery and what Locke himself administered. Historians genuinely disagree about how much of that scheme is his. The episode gives that dispute at full strength, sits with the offense before reaching for anything redemptive, and only then asks what it means that his principles proved larger than the man who stated them.

Did that leave people more free, or more governed? Take a law or policy in your own country today. Does it rest on powers the governed could actually have delegated, protecting rights they already held?

⏱️ CHAPTERS

* 00:00 Introduction: The Treason Trial of Algernon Sidney

* 03:25 Episode Overview: The Martyr and the Philosopher

* 04:28 The Exclusion Crisis and the Popish Plot

* 08:08 Sir Robert Filmer and the Divine Right of Kings

* 11:21 Algernon Sidney’s “Discourses Concerning Government”