“The Martyr and the Philosopher” — Algernon Sidney and John Locke

“We live in an age that maketh truth pass for treason.”— Algernon Sidney, in the paper delivered to the sheriffs on the scaffold, Tower Hill, 7 December 1683¹

The Scaffold

On the morning of 7 December 1683, a sixty-year-old man walked out onto a scaffold on Tower Hill to be beheaded for a book almost no one had read.

Algernon Sidney declined to make a public speech. By the account of the diarist John Evelyn, who set the scene down soon after, Sidney told the sheriffs only that he had made his peace with God, that he had come not there to talk but to die, put one paper into a sheriff’s hand and another into a friend’s, said a prayer as short as a grace, laid his neck on the block, and told the executioner to do his office.² The paper he handed over contained the argument he would not speak aloud. It ended with a sentence that has outlived the man, the reign, and the axe: that he lived in an age that made truth itself pass for treason.

The truth in question was a manuscript. Sidney had spent years writing a long, dense, furious refutation of the theory that kings rule by a title God gave to Adam — a book he called Discourses Concerning Government. He had shown it to almost no one. It sat unfinished and unpublished in his study when the king’s officers came for his papers in the summer of 1683, in the roundup that followed the discovery of a plot against the life of Charles II. The crown’s case connecting Sidney to the plot rested principally on a single compromised and widely distrusted witness, Lord Howard of Escrick; no second living witness corroborated the alleged overt act of treason that the law required be proved by two. So the prosecution reached into Sidney’s study, pulled out the unpublished manuscript, and offered the book itself to stand in for the missing second witness.

The judge was George Jeffreys, whose conduct on the bench was a byword for cruelty in his own time and has not improved with age. Jeffreys instructed the jury on the point of law with a Latin phrase that ought to chill anyone who has ever written a sentence they would not want read aloud in a hostile room: scribere est agere. To write is to act.³ If the jury believed the manuscript was Sidney’s, then the writing of it was itself the overt act of treason, and the second witness the law demanded was the defendant’s own pen. The Solicitor General told the court the book was nothing less than an argument for the people to rise up in arms against the king.⁴ On that reasoning Sidney was convicted, and a few weeks later, on the scaffold, the crimson fell across the blade.

A man was killed for what he had written in private and never published. It is worth truly considering that fact still for a moment, because it tells us something about the stakes of the ideas this article concerns. These were not abstractions to be debated at leisure. In the England of the 1680s, the proposition that no king could derive an unanswerable title from Adam — and that legitimate power rested instead on law, the public good, and some form of consent — was dangerous enough to help cost a man his head, and the men who argued it knew exactly what they were risking. Sidney’s private papers fell into the government’s hands and were turned against him. The other figure in this article, writing a kindred argument at the same moment and in the same danger, escaped into exile and published his own manuscript only years later, anonymously, once the regime that would have killed him for it was gone. To understand why two of the most careful minds in England were writing in fear for their lives, we have to understand what they were writing against.

What Sidney and Locke Argued Against

The target had a name, and the name was Sir Robert Filmer.

Filmer was an English royalist who had died in 1653, but his great defense of absolute monarchy, Patriarcha, was published in 1680, at the height of the crisis over whether a Catholic could be permitted to inherit the English throne. Its timing made it one of the most important theoretical defenses of hereditary royal authority in the Exclusion Crisis, and both Sidney and Locke set out to destroy it. Before we watch them do so, we should allow Filmer to be stated at his strongest.

Filmer’s case was this. The whole fashionable theory that government arises from the consent of free and equal individuals is a fiction, and a dangerous one. Look at the actual world. No one is born free. Every human being enters life under a power he never chose — the rule of a father, into a family he did not choose, subject to rules he never consented to. Authority is not something individuals construct by agreement; it is the condition into which everyone is born. And its origin, Filmer argued, is divine and historical at once. God gave Adam dominion over the created world and over his own children. That paternal power — the natural, unquestioned rule of a father over his household — descended through the patriarchs to the kings of the earth, who are, in effect, the fathers of their peoples. A king’s command over his subjects is the same kind of thing as a father’s over his children: natural, God-given, and requiring no one’s consent, because no child ever consents to the parent who raises him.

The power of this argument is that it described something real. Filmer looked at how human beings actually live — born into families, into obligations, into hierarchies they never chose — and asked the consent theorists a hard question. When, exactly, did you consent? Where is this original agreement you speak of? Who signed it? Show me a single government on earth that was founded by the free assembly of equal individuals rather than established by conquest, inheritance, or the slow accretion of custom. The state of nature, the social contract, the free and equal individuals choosing their government — Filmer called these things imaginary, unsupported by history, Scripture, or ordinary experience. Real authority, he insisted, is inherited and natural, not chosen. It was a serious argument, and it demanded a serious answer. Sidney and Locke each gave one.

Sidney: The Right of Resistance

Sidney’s answer runs to hundreds of pages, but its spine is straightforward. Filmer’s whole edifice rests on a claim about Adam, and the claim about Adam is false.

Even if God had given Adam some special dominion — which Sidney disputed — there is no way to trace that authority to any king now living. The line from Adam to, say, Charles II is not a line at all; it is a fiction dressed up as a genealogy. If paternal authority were the true source of kingship, then every father would b

e a king, and the world would have as many sovereigns as it has households. And if we cannot actually trace any living king’s title back to Adam, then Filmer’s theory, whatever its logical shape, tells us nothing about who should rule England. Sidney turned Filmer’s demand for evidence back on Filmer: you accuse the consent theorists of inventing history, but your own descent of kings from Adam is the greater invention.

With Adam removed, the ground was clear for Sidney’s own position, which he drew from the classical republican tradition and from a reading of English history as a long record of limited, answerable kingship. Men, Sidney argued, are naturally free — not free in the sense that they live without government, but free in the sense that no man is born the natural master of another, and no man is bound to obey a power he or his ancestors did not in some way establish or consent to. Government exists for the good of the governed, not for the private benefit of the governor. Its powers are therefore limited by the purpose for which it exists. And when a ruler breaks those limits — when he governs against the law, against the good of the people, for himself alone — he becomes a tyrant, and the people who established the government retain the right to resist him.

This is the doctrine that cost Sidney his life, and the crown understood it precisely. A theory that grounds a king’s authority in the consent and the good of his people is also, unavoidably, a theory about when that authority may be withdrawn. Filmer’s patriarchal king can never be lawfully resisted, any more than a child may lawfully depose his father. Sidney’s answerable magistrate can be. The whole question of the age — whether there was any lawful limit to what a king could do, and any lawful remedy when he exceeded it — turned on exactly this point. Sidney answered that there was a limit and a remedy, and he wrote it down, and the writing was used to kill him.

It is worth being careful about what Sidney was and was not arguing. He was not a democrat in any modern sense, and it would flatter him falsely to make him one. His republic was one of virtuous, propertied, public-spirited men; his admiration ran to the aristocratic republics of antiquity, not to anything resembling universal suffrage. The “people” in whom he located the ultimate authority were not the whole population. What Sidney established, and established with a rigor and a courage that made him a martyr, was the principle underneath the franchise question: that under God and the natural law, particular governments are established by human beings for their common good, hold their power on behalf of the governed, and remain answerable to the communities that authorized them — rather than descending by a divine hereditary title to a sovereign who answers to no one. Who counts as the governed was a question later generations would press further than Sidney ever did. That the governed, whoever they are, are the source rather than the subjects of legitimate power — that was Sidney’s enduring contribution, and he sealed it with his death.

Locke: The Systematic Case

The other man writing against Filmer in those same years worked in secret and lived to see his argument triumph.

John Locke was a physician, philosopher, and adviser to the Earl of Shaftesbury, the leader of the movement to exclude the Catholic heir from the throne. When that movement collapsed and its leaders faced arrest, Locke fled to the Dutch Republic — the same republic whose long struggle for liberty this series traced several articles ago — and waited. His great work of political theory, the Two Treatises of Government, was published anonymously in 1689, after the Glorious Revolution had already driven the last Stuart king from the throne. For a long time it was read as a justification written after the fact, a defense of a revolution already won.

Modern scholarship, beginning with Peter Laslett’s landmark edition of 1960, has corrected that picture, and the correction matters for understanding what kind of book this was. The Two Treatises was not composed as a comfortable justification of a victory already achieved. Most of it was written years earlier — substantially during the Exclusion Crisis and its immediate aftermath, probably between roughly 1679 and 1682 — written, that is, as a revolutionary argument in a losing cause, at a time when making it openly could have put its author on the same scaffold as Sidney.⁵ Locke published it only when it was safe to do so, and even then without his name. The systematic calm of the prose conceals the danger of its composition. This was a manuscript written in the same peril that killed Sidney, by a man who escaped into exile where Sidney’s papers fell into the government’s hands.

The First Treatise is a direct, patient demolition of Filmer, working through Patriarcha almost line by line and taking apart the descent of authority from Adam. But it is the Second Treatise that built the structure the future would inhabit, and it is worth laying out its argument in order, because much of the natural-rights and consent-based vocabulary the American revolutionaries would later use is contained in it.

Locke begins where Filmer said no one could begin: with human beings as they are by nature, prior to any government. In this state of nature, men are free and equal — not free to do anything they wish, but bound by a law of nature, which is reason, and which teaches, in Locke’s words, that being all equal and independent, no one ought to harm another “in his life, health, liberty, or possessions.”⁶ Rights are not the gift of government. They exist before government, in the moral structure of the human person. Government does not create them; it is created to protect them.

From this root Locke derived the theory of property that would prove one of his most consequential and most contested legacies. Every man, Locke wrote, “has a property in his own person: this no body has any right to but himself.”⁷ That claim supplies the starting point. From it, property in things follows: because a man owns the labor of his own body, when he applies that labor to something originally given to humankind in common — clearing a field, gathering the harvest, drawing water — he joins something of himself to it and makes it his own.⁸ Locke’s premise here was not that the world lay ownerless, but that God had given the earth to human beings in common; individual property arises when labor is mixed with that common stock. Later thinkers would develop the property-in-one’s-person into a fuller doctrine of self-ownership, though Locke himself set a limit on a person’s dominion over himself, holding that human beings are ultimately the workmanship and property of their Maker and so may not, for instance, destroy or wholly enslave themselves. Property, in Locke’s account, is not a grant from the sovereign that the sovereign may therefore revoke. It arises from labor, before and independent of government, and it sets a limit on what any government may rightly do. A ruler who takes his subjects’ property at will is not exercising a legitimate power; he is committing the very theft that government exists to prevent. Locke did attach a condition — that a man may appropriate from the common store only where there is, as he put it, “enough, and as good, left in common for others.”⁹ We will return to the difficulty hidden in that condition when we come to the reckoning.

Because rights precede government, government can rest only on one legitimate foundation: the consent of those who are to be governed. Men leave the state of nature and form a political society for a definite and limited purpose — the better protection of the lives, liberties, and property they already possess. They hand to government only the powers needed for that purpose. Government therefore holds its authority in trust. It is not a master but a fiduciary, entrusted with power for the people’s benefit and bounded by the terms of the trust.

And from the idea of trust follows the conclusion that made the book revolutionary in fact and not only in theory. When a government breaks the trust — when it makes itself arbitrary, seizes the property it was established to protect, and places itself in a state of war with its own people — then power reverts to the people who conferred it, and they may alter or abolish that government and provide for their own safety anew. Locke hedged the right of revolution with cautions. It is not triggered by every grievance or maladministration; people do not and should not overturn their governments over small or occasional faults. But a long train of abuses aimed at reducing a people under absolute power — that dissolves the trust and returns to the people the authority they had lent. Set that sentence beside a document written on the other side of an ocean nearly a century later, and the debt is unmistakable. But the debt is a matter for the transmission section; first the reckoning, because these two men and their ideas carried shadows that honesty will not let us leave in the dark.

The Honest Reckoning

Two very different reckonings are owed here, one for each man, and the second is among the hardest this series has had to write.

Sidney first, because his is the simpler case. The martyr was not a saint. For all the nobility of his death and the rigor of his book, Sidney accepted secret money from the French ambassador — two payments of five hundred guineas, in 1678 and 1679 — while cooperating with French policy against the English court, and he had sought French support for republican action in his earlier exile as well.¹⁰ The very absolutist monarch whose model of kingship stood as the great threat to English liberty was thus, at moments, the republican hero’s paymaster, and when this became known it did lasting damage to his reputation, as well it might. The defense that can be offered is real but partial: subsidies flowed in many directions in the diplomacy of the era, and taking French money to advance ends one already held is not the same as selling one’s convictions. But it does not dissolve the tension. A man who wrote with such force against arbitrary power took coin from its most powerful European exemplar, and the account must hold both the courage of the Discourses and the compromise of the payments without letting either cancel the other.

Locke’s reckoning is deeper, and it cuts closer to the heart of what he wrote. The philosopher who grounded all legitimate government in the natural freedom and equality of every person was personally and materially entangled in the enslavement of human beings. Locke held shares in the Royal African Company, the chartered corporation centrally involved in England’s trade in enslaved Africans, and in a Bahama Adventurers venture beside it; recent manuscript research indicates that these shares were transferred to him, probably as compensation for colonial administrative work, rather than bought as an ordinary personal investment — a distinction that refines the picture without erasing the connection.¹¹ As secretary to the Lords Proprietors of Carolina, he copied, revised, and helped administer versions of the Fundamental Constitutions of Carolina, a proposed foundational constitution for that colony, which declared that every freeman of Carolina should have “absolute power and authority over his negro slaves.”¹² The man who wrote that no one may harm another in his life, liberty, or possessions was directly involved in preparing and administering a colonial constitution that entrenched slaveholding.

The gap between the philosophy and the conduct is not a small hypocrisy to be noted and set aside. It is a wound at the center of the liberal tradition, and it will not be honestly dressed by pretending it is smaller than it is. The words Locke wrote — natural freedom, equality, the rights that precede all government — are the words that antislavery writers would later turn against slavery with force, even as defenders of slavery selectively enlisted Locke too; the language proved usable against the very order Locke had helped build.¹³ That the principles proved larger than the man who stated them is the redemptive fact, and it is a real one. But it does not come first. What comes first is that a philosopher of universal freedom held shares in human bondage and was directly involved in preparing a slaveholders’ constitution, and any account that reaches for the redemption before it has sat with the offense has cheated.

Two further points belong here, in the interest of stating the dispute honestly rather than scoring it. The first is that the degree of Locke’s personal responsibility for the Carolina slavery clauses is genuinely contested among historians: some read him as an active architect of the colony’s slave order, others as a secretary implementing the settled will of the proprietors who employed him, working from charters and models that predated and outlasted his involvement. The evidence does not resolve cleanly, and this article will not pretend it does. The second is the harder interpretive question — whether Locke’s political philosophy itself was written to rationalize colonial slavery and dispossession, or whether his entanglement was a personal failing at odds with a theory whose own logic condemns it. That, too, is genuinely disputed. What can be said without dispute is that the entanglement was real, that it was grave, and that the theory’s universal language was in permanent tension with its author’s particular conduct. The tension is the honest place to stand.

There is a related difficulty in the theory itself, and it connects back to that quiet condition on property. Locke justified private appropriation so long as there was “enough, and as good, left in common for others” — and he repeatedly described America as a vast, underused common, land lying waste for want of the labor that would make it property. That description, whatever Locke intended by it, supplied a ready argument for treating the lands of Native peoples as empty and available, their existing ways of using the land not counting as the kind of labor that established ownership. Whether Locke meant his theory to license colonial dispossession, or whether later readers turned it to that use, is once again disputed. That the argument was available for that use, and was used that way, is not.¹⁴

The Skeptic’s Case

Against the account offered here, a serious reader can raise several objections, and each deserves its full strength before any reply.

The Straight Line to Jefferson Is Too Straight

The first objection targets the transmission claim before it is even made. The familiar story — Locke wrote it, Jefferson read it, the Declaration echoes it, therefore American liberty is Lockean liberty — is too clean by half. A generation of scholars has argued that the intellectual world of the American founders was far more crowded than the Locke-to-Jefferson line suggests: that classical republicanism, the tradition of civic virtue running from the ancient historians through the Renaissance to the English commonwealthmen, shaped the revolutionary generation at least as much as Lockean natural rights; that Scottish moral philosophy, common-law constitutionalism, and dissenting Protestant thought all fed the stream; that plucking Locke out of that crowd and crowning him the single father of American liberty is a retrospective simplification that tells us more about later admirers than about the founders themselves. On this account, to make Locke and Sidney the twin pillars of 1776 is to build a tidy genealogy where the truth was a tangle.

This objection is right about the tangle, and the reply is not to deny it but to be precise about what is claimed. The founders were not simple Lockeans, and this series has taken pains from its first article to present the American synthesis as exactly that — a synthesis, braiding classical, common-law, Protestant, and natural-rights strands, no one of which stands alone. Locke and Sidney are not the whole of it. What can be said, and what the evidence firmly supports, is that they were prominent and documented strands, named as such by the founders in their own words. When Thomas Jefferson, late in life, set down the sources of the Declaration’s authority, he did not claim originality; he said the document was meant to be an expression of the American mind, drawn from “the elementary books of public right, as Aristotle, Cicero, Locke, Sidney.”¹⁵ When the Board of Visitors of the University of Virginia, with Jefferson as rector and Madison present, resolved which books should teach the principles of government to the new republic’s students, they named the doctrines of Locke’s Second Treatise and Sidney’s Discourses as expressing principles the board described as “generally approved” — “the general principles of liberty and the rights of man in nature and in society.”¹⁶ That is not a genealogy imposed by later admirers. It is the founders identifying their own sources, and putting Locke and Sidney at the center of them without making them the whole. The strand is documented, named, and central. It is simply not solitary, and this article does not claim that it is.

Sidney Was a Factional Martyr, Not a Philosopher of Liberty

The second objection presses on Sidney. His martyrdom, it says, was real but partly self-made, and his cause was a faction’s cause, not liberty’s. He was an aristocrat defending the prerogatives of his class against the crown, a man mixed up in the murky plotting of the Exclusion Crisis, funded by a foreign king, whose canonization as a hero of liberty was the work of later Whig propaganda that needed a martyr and found a convenient one. To read the Discourses as a monument of freedom, on this view, is to accept a partisan legend at face value.

The facts beneath this objection are largely conceded in the reckoning above: Sidney was an aristocrat, was entangled in faction, did take French money, and was indeed elevated into a symbol by admirers with their own purposes. But the concession does not reach the argument, and it is the argument that matters. Whatever the mixture of Sidney’s motives and the impurities of his cause, the Discourses makes a case that stands or falls on its own reasoning, not on the character of its author — and the case, that authority derives from the governed and that tyranny may be lawfully resisted, is not a factional convenience but a general principle. Bad men and mixed men can articulate true and important things; the truth of a proposition does not depend on the purity of the person advancing it. And the manner of Sidney’s death gave the principle a force that no treatise alone could have carried. A government that kills a man for an unpublished book demonstrates his thesis about arbitrary power more vividly than any argument he could have written.

Locke’s Liberty Was a Property-Holder’s Liberty

The third objection is the sharpest, and it grows directly from the reckoning. Locke’s natural rights, it holds, were in practice the rights of propertied European men, and his philosophy functioned to protect and expand their holdings — including holdings in land taken from Native peoples and in human beings taken from Africa. His labor theory of property reads, on this account, less like a charter of universal freedom than like a rationalization of accumulation and dispossession, dressed in the language of nature and reason. The universalism was a facade; the function was the protection of a particular class’s particular interests.

This is the objection to respect most, because the reckoning has already conceded the facts that give it force. Locke was entangled in slavery and colonialism; his theory of property was available as a justification for dispossession; the universal language coexisted with a decidedly non-universal practice. What the objection asserts beyond those facts, however — that the universalism was mere facade, that the function exhausts the meaning — is precisely what the subsequent history refuses to confirm. If Locke’s language of natural freedom and equality had really been nothing but a property-holder’s charter, it could not have done the work it went on to do: it was taken up by antislavery and reform movements, and by people the exclusions had shut out, who turned Locke’s own premises against those exclusions. A facade cannot be used to tear down the building it was meant to decorate. That Locke’s principles could be, and were, turned against Locke’s own conduct and his era’s injustices is the strongest evidence that they were not merely a rationalization of those injustices. The words meant more than their author lived up to. That is not a defense of the author. It is a claim about the words, and the history of what was done with them bears it out.

The Books That Crossed the Ocean

Sidney died in 1683. His Discourses was published fifteen years later, in 1698, and went through edition after edition in the century that followed. Locke’s Two Treatises appeared in 1689 and became, over the next several generations, one of the most quietly influential books in the English-speaking world. Both men had written in danger and in the shadow of defeat. Both were read, in the fullness of time, by people they could never have imagined, in a country that did not yet exist.

By the middle of the eighteenth century, Sidney and Locke were fixtures in the libraries and the arguments of educated colonial Americans. When the quarrel with Britain drove the colonists to search for the principles on which to ground their resistance, these were among the books they reached for — and, crucially, they said so. The American founders were not shy about their sources, and they explicitly named both men when describing the intellectual foundations of the Declaration and, later, the curriculum of republican government. Jefferson placed Locke and Sidney among the handful of elementary books of public right from which the Declaration drew the common sense of the subject. He praised Sidney’s Discourses as probably the best book of its kind on the principles of government founded in natural right ever published. Late in his life, helping to build a university for the new republic, he and the Board of Visitors wrote into its curriculum the doctrines of Locke’s Second Treatise and Sidney’s Discourses as statements of principles they described as generally approved by their fellow citizens.

The transmission here is not a matter of resemblance noticed after the fact, as it partly was with the Levellers of the previous article. It is documented in the founders’ own words. The reservation entered above still holds — Locke and Sidney were prominent, documented strands and not the whole cloth, and the American synthesis braided them with much else. But within that synthesis their thread is bright, traceable, and acknowledged by the men who wove it. The argument that authority comes from the consent of the governed, that rights precede government, that property is founded in labor and not in the sovereign’s grant, that a government which breaks its trust may be replaced — this argument, refined in danger by a philosopher who escaped into exile and a republican who died, crossed the ocean and became part of the working vocabulary of a revolution.

The Road Continues

The martyr and the philosopher had answered Filmer’s hard question. When did you consent? Where is the agreement? Their answer was not to produce a signed contract from the dawn of history but to reground the whole question: authority is legitimate only where it serves the governed and rests, however imperfectly, on their consent, and it forfeits its claim when it turns against them. Sidney sealed that answer with his death; Locke built it into a system that a later age would quarry for a century. The argument from nature and consent that the Levellers had raised in the streets and the barracks now had its rigorous, enduring statement — two statements, written independently against the same enemy, in the same years, at the same risk.

But an argument on paper, however rigorous, is not yet a change in the world. Sidney was executed; Locke fled; the immediate cause for which both wrote appeared, in 1683, to have failed utterly. What neither man could have predicted from the scaffold or the exile was how quickly the wheel would turn. Within five years the king for whom Sidney died would be dead, his Catholic brother would sit briefly on the throne, and that brother would be driven from the English throne with comparatively little fighting in England — though the wider revolution brought armed conflict to Scotland and a full war to Ireland. The settlement that followed did not enact Sidney’s or Locke’s systems wholesale; it placed new statutory and political restraints on royal power and secured inherited constitutional rights. But it created an order in which the arguments that had been treason in 1683 could circulate with far greater safety and force. The theory was about to meet its moment. To the revolution that placed fresh limits on the crown and set down a bill of rights, and to the constitutional settlement that Locke lived to see and to defend, the next article turns.

This is the road to 1776, and we are still walking it.

Self-Reflection Prompts

1. Filmer asked the consent theorists a hard question: no one is born free, everyone enters life under authority they never chose, so where is this original consent that supposedly grounds government? Sidney and Locke answered by regrounding the question rather than producing a signed contract. Do you find their answer satisfying? When you obey the laws of the country you were born into, in what sense, if any, have you consented to them — and does it matter whether you have?

2. Locke argued that rights exist before government, in the moral structure of the person, and that government is created to protect rights it did not create and may not violate. The rival view is that rights are whatever a society grants and can therefore withdraw. Which account do you hold, and what follows from it? If rights come before government, what is the remedy when a government violates them; if they come from government, what protects them from it?

3. Locke made a person’s property in his own person central to his account of labor and appropriation, while holding that human beings ultimately belong to their Maker and so possess no unlimited dominion over themselves. How far does the idea of owning oneself extend? If you have a property in your own person, what may a government legitimately require of you, and where does that ownership set a boundary that no law may cross — and does the theological limit Locke placed on it change your answer? Consider a hard case where the answer is not obvious.

4. The reckoning with Locke is among the hardest in this series: a philosopher of universal freedom who was materially entangled in slavery and directly involved in preparing a slaveholders’ constitution. How should we hold a thinker whose principles were larger than his conduct? Does the entanglement discredit the philosophy, or does the philosophy stand as an indictment of the entanglement — and who gets to decide which?

5. The Liberty Test. Sidney and Locke grounded legitimate authority in the consent of the governed and the protection of rights that precede government, and concluded that a government which breaks that trust may be resisted or replaced. Measured against the question this series always asks — did it leave people more free, or more governed? — consider a law or policy in your own country today. Does it rest on powers the governed could actually have consented to delegate, protecting rights they already held? Or does it claim an authority over them that no free person would have handed over — the very kind of arbitrary power Sidney and Locke wrote, and one of them died, against?

Endnotes

1. Algernon Sidney, The Very Copy of a Paper Delivered to the Sheriffs, upon the Scaffold on Tower-Hill, on Friday December 7. 1683 (London, 1683). The paper is reprinted in later editions of Sidney’s Discourses Concerning Government; see Algernon Sidney, Discourses Concerning Government, ed. Thomas G. West (Indianapolis: Liberty Fund, 1996), appendix. Spelling modernized. Sidney’s exact scaffold conduct and the delivery of the paper are described in note 2.

2. John Evelyn, The Diary of John Evelyn, ed. E. S. de Beer (Oxford: Clarendon Press, 1955), entry for 7 December 1683. Evelyn records that Sidney “came not thither to talk but to die,” delivered a paper to the sheriffs, said a short prayer, and submitted to the executioner. The account here follows Evelyn’s; the physical blocking beyond what Evelyn records is left general. Sidney was born 15 January 1623 and was therefore aged sixty at his death.

3. On the trial (7 November 1683) before Lord Chief Justice George Jeffreys, the reliance on the unpublished Discourses manuscript as the second witness required by the Treason Act, and the ruling “scribere est agere,” see The Trial of Algernon Sidney, in A Complete Collection of State Trials, ed. T. B. Howell, vol. 9 (London, 1816), cols. 817–902; and Jonathan Scott, Algernon Sidney and the Restoration Crisis, 1677–1683 (Cambridge: Cambridge University Press, 1991), chaps. 12–13. The sole living witness was William Howard, 3rd Baron Howard of Escrick. The manuscript did not literally become a second witness in the ordinary sense: Jeffreys allowed proof of the Discourses and of Sidney’s authorship to serve as evidence of a separate overt act of compassing the king’s death, circumventing the practical protection of the two-witness rule — “the manuscript as second witness” is conventional shorthand for that maneuver. Sidney’s attainder was reversed by Parliament in 1689 as wrongful and unjust.

4. Heneage Finch, Solicitor General, characterized the Discourses as an argument for the people to rise in arms against the king; see The Trial of Algernon Sidney, in State Trials, ed. Howell, vol. 9, cols. 817–902. Sidney’s rejoinder that quotation out of context could convict any author, including the writers of Scripture, is recorded in the same account.

5. On the composition of the Two Treatises during the Exclusion Crisis and its immediate aftermath — substantially before the Revolution of 1688, probably between roughly 1679 and 1682, rather than as a post hoc justification of 1688 — see Peter Laslett’s introduction to John Locke, Two Treatises of Government, ed. Peter Laslett (Cambridge: Cambridge University Press, 1960), which established the earlier dating, together with the addendum in later printings acknowledging that the precise reconstruction has been disputed; and Richard Ashcraft, Revolutionary Politics and Locke’s “Two Treatises of Government” (Princeton: Princeton University Press, 1986), placing composition approximately in 1680–82. The work was published anonymously in 1689 (title page 1690).

6. John Locke, Two Treatises of Government, ed. Peter Laslett (Cambridge: Cambridge University Press, 1988), Second Treatise, sec. 6, 271: in the state of nature, the law of nature teaches “that being all equal and independent, no one ought to harm another in his life, health, liberty, or possessions.” On the purposes of political society and the ends of government, see also Second Treatise, secs. 123–31.

7. Locke, Two Treatises, ed. Laslett, Second Treatise, sec. 27, 287–88: “every man has a property in his own person: this no body has any right to but himself.”

8. Locke, Two Treatises, ed. Laslett, Second Treatise, sec. 27, 288: on mixing one’s labor with what nature has provided and thereby making it one’s property.

9. Locke, Two Treatises, ed. Laslett, Second Treatise, sec. 27, 288: appropriation is legitimate “at least where there is enough, and as good, left in common for others.” The proviso is discussed in the reckoning below. On government as a trust and the people’s appeal against its violation, see Second Treatise, secs. 149, 221–22, and 240–43.

10. On Sidney’s dealings with the French ambassador Paul Barillon, including payments reported at five hundred guineas in 1678 and again in 1679, and his earlier efforts to obtain French assistance for republican action during his exile, see Jonathan Scott, Algernon Sidney and the Restoration Crisis, 1677–1683 (Cambridge: Cambridge University Press, 1991), and the chronology in the same author’s edition; these dealings are the source of Sidney’s later reputation as a pensioner of France. Taking foreign subsidy to advance ends one already held was common in the diplomacy of the period; it is recorded here as a genuine compromise, not offered as exculpation.

11. Locke held shares in the Royal African Company and in a Bahama Adventurers venture. Recent manuscript research finds that all the shares he came to own were transferred to him from third parties — recorded in his personal ledger from February 1672, payments made on his behalf by Thomas Stringer, Ashley Cooper’s steward — probably as compensation for his colonial administrative work, rather than acquired by ordinary personal purchase; Locke later divested all of them, and there is no evidence that his income was funded by company profits (the Company was not producing profits during the relevant period). See Brian Smith, “John Locke’s Royal African Company and Bahamas Adventurer Slave Stock,” History of Political Thought 46, no. 2 (2025): 259–84, correcting the earlier account in Maurice Cranston, John Locke: A Biography (London: Longmans, Green, 1957). The distinction refines, but does not erase, Locke’s material connection to the enterprise.

12. The Fundamental Constitutions of Carolina (1669), art. 110 (art. 101 in the 1669 scheme): “Every freeman of Carolina shall have absolute power and authority over his negro slaves, of what opinion or religion soever.” Text in The Federal and State Constitutions, ed. Francis Newton Thorpe (Washington, DC: Government Printing Office, 1909), vol. 5; and at the Avalon Project, Yale Law School. As secretary to the Lords Proprietors, Locke copied, revised, and helped administer versions of the document, which went through several schemes and was only partially implemented. His personal responsibility for composing the slavery provisions is contested: David Armitage, “John Locke, Carolina, and the Two Treatises of Government,” Political Theory 32, no. 5 (2004): 602–27, reads Locke as actively endorsing the colony’s slave order; Holly Brewer, “Whose Fundamental Constitutions? Locke, Slavery, and Manuscript Evidence,” Locke Studies 24 (2024): 1–57, argues from the manuscript evidence that the slavery provisions cannot be securely attributed to Locke’s authorship and point rather to the Lords Proprietors and the crown. See also Brad Hinshelwood, “The Carolinian Context of John Locke’s Theory of Slavery,” Political Theory 41, no. 4 (2013): 562–90; and James Farr, “’Absolute Power and Authority’: John Locke and the Revisions of the Fundamental Constitutions of Carolina,” Locke Studies 20 (2020): 1–49.

13. On the reception of Locke’s language in the slavery debates, where antislavery writers drew on his premises of natural liberty, self-ownership, and express consent while pro-slavery apologists also enlisted him selectively before turning against him in the nineteenth century, see Brian Smith, “John Locke, Abolitionism, and the Reactionary Enlightenment,” Journal of Modern Philosophy 6, no. 2 (2024): 1–24.

14. On Locke’s account of America as underused common land and its availability as a justification for colonial dispossession — whether by Locke’s intent or in the use later readers made of it — see Barbara Arneil, John Locke and America: The Defence of English Colonialism (Oxford: Clarendon Press, 1996); and Barbara Arneil, “John Locke, Natural Law and Colonialism,” History of Political Thought 13, no. 4 (1992): 587–603.

15. Thomas Jefferson to Henry Lee, 8 May 1825, in The Writings of Thomas Jefferson, ed. Paul Leicester Ford, vol. 10 (New York: G. P. Putnam’s Sons, 1899), 343: the Declaration was “intended to be an expression of the American mind,” drawn from “the elementary books of public right, as Aristotle, Cicero, Locke, Sidney, &c.”

16. Minutes of the Board of Visitors of the University of Virginia, 4 March 1825 (Thomas Jefferson, Rector; James Madison present), in The Papers of Thomas Jefferson: Retirement Series, or as reproduced by the Founders Online project, National Archives: resolving that “as to the general principles of liberty and the rights of man in nature and in society, the doctrines of Locke, in his ‘Essay concerning the true original extent and end of civil government,’ and of Sidney in his ‘Discourses on government,’ may be considered as those generally approved by our fellow-citizens.” Jefferson’s separate praise of the Discourses as “probably the best elementary book of the principles of government, as founded in natural right, which has ever been published in any language” appears in Thomas Jefferson to Mason Locke Weems, 13 December 1804 (Library of Congress; Jefferson’s own copy of the Discourses is catalogued in E. Millicent Sowerby, Catalogue of the Library of Thomas Jefferson, vol. 3, no. J6).

Sources and Further Reading

Primary Sources

• Algernon Sidney, Discourses Concerning Government, ed. Thomas G. West (Indianapolis: Liberty Fund, 1996). Based on the 1698 first edition; includes the scaffold paper.

• Algernon Sidney, The Very Copy of a Paper Delivered to the Sheriffs, upon the Scaffold on Tower-Hill (London, 1683).

• John Locke, Two Treatises of Government, ed. Peter Laslett (Cambridge: Cambridge University Press, 1988). The standard critical edition, with Laslett’s landmark introduction on dating.

• John Locke, A Letter Concerning Toleration, ed. James Tully (Indianapolis: Hackett, 1983).

• Sir Robert Filmer, Patriarcha and Other Writings, ed. Johann P. Sommerville (Cambridge: Cambridge University Press, 1991).

• The Fundamental Constitutions of Carolina (1669). In The Federal and State Constitutions, ed. Francis Newton Thorpe (Washington, DC: Government Printing Office, 1909), vol. 5.

• A Complete Collection of State Trials, ed. T. B. Howell, vol. 9 (London, 1816). Contains the report of Sidney’s 1683 trial.

• Thomas Jefferson to Henry Lee, 8 May 1825, and the Minutes of the Board of Visitors of the University of Virginia, 4 March 1825, both in Founders Online, National Archives.

Secondary Works

• Jonathan Scott, Algernon Sidney and the Restoration Crisis, 1677–1683 (Cambridge: Cambridge University Press, 1991). The standard modern study of Sidney’s thought and trial.

• Peter Laslett, introduction to Locke, Two Treatises of Government (Cambridge University Press, 1960). Established the Exclusion-Crisis dating of the Two Treatises.

• Richard Ashcraft, Revolutionary Politics and Locke’s “Two Treatises of Government” (Princeton: Princeton University Press, 1986). On the radical political context of Locke’s composition.

• John Dunn, The Political Thought of John Locke (Cambridge: Cambridge University Press, 1969). On the intellectual origins and character of Locke’s argument.

• David Armitage, “John Locke, Carolina, and the Two Treatises of Government,” Political Theory 32, no. 5 (2004): 602–27. On Locke’s colonial entanglements and their relation to the text.

• Brad Hinshelwood, “The Carolinian Context of John Locke’s Theory of Slavery,” Political Theory 41, no. 4 (2013): 562–90.

• Holly Brewer, “Whose Fundamental Constitutions? Locke, Slavery, and Manuscript Evidence,” Locke Studies 24 (2024): 1–57. Reassesses, against Armitage, the manuscript evidence for Locke’s authorship of the Carolina slavery provisions.

• Brian Smith, “John Locke’s Royal African Company and Bahamas Adventurer Slave Stock,” History of Political Thought 46, no. 2 (2025): 259–84. On how Locke came to hold his slave-trading company shares.

• Brian Smith, “John Locke, Abolitionism, and the Reactionary Enlightenment,” Journal of Modern Philosophy 6, no. 2 (2024): 1–24. On the contested use of Locke by both abolitionists and pro-slavery writers.

• Barbara Arneil, John Locke and America: The Defence of English Colonialism (Oxford: Clarendon Press, 1996). On Locke’s theory of property and colonial dispossession.

• Bernard Bailyn, The Ideological Origins of the American Revolution, enl. ed. (Cambridge, MA: Belknap Press, 1992). On the classical-republican and commonwealth strands in founding-era thought.

• J. G. A. Pocock, The Machiavellian Moment: Florentine Political Thought and the Atlantic Republican Tradition (Princeton: Princeton University Press, 1975). The major statement of the republican-synthesis reading.

• Caroline Robbins, The Eighteenth-Century Commonwealthman (Cambridge, MA: Harvard University Press, 1959). On the transmission of Sidney, Locke, and the commonwealth tradition to America.

• Michael P. Zuckert, Natural Rights and the New Republicanism (Princeton: Princeton University Press, 1994). On the natural-rights and republican strands and their synthesis.

  
  

Next: Article 11 — “The Glorious Revolution”