Introduction

There are books that describe the world, and there are books that change it. John Locke’s Second Treatise of Government belongs unmistakably to the second category. Written in the turbulent final decades of the seventeenth century and published anonymously in 1689, this slim but extraordinarily potent work of political philosophy did nothing less than supply the intellectual scaffolding upon which much of the modern political order would later be built. Its arguments about consent, natural rights, the limits of authority, and the right of a people to resist tyranny have echoed through revolutions, constitutions, and declarations across continents and centuries. When Thomas Jefferson sat down to draft the American Declaration of Independence, the cadences and convictions of Locke were unmistakably present. When later generations argued for the rule of law over the rule of kings, for government accountable to the governed, for the sanctity of individual liberty, they were—knowingly or not—drawing from the well that Locke had dug.

Yet for all its monumental influence, the Second Treatise is not a remote or forbidding text. At its heart it asks questions that any thoughtful person, in any age, has reason to ask: Where does political power come from? What gives one human being the right to command another? What do we owe to those who govern us, and what do they owe to us? When, if ever, is it justified to resist authority? These are not antique curiosities. They are living questions, as urgent in the twenty-first century as they were in the seventeenth. To read Locke is to be invited into a conversation about the foundations of freedom itself—a conversation that has never truly ended.

This edition, adapted as a modern translation for the contemporary reader, exists precisely to make that invitation easier to accept. Locke wrote in the dense, elaborate prose of his era, with long winding sentences, archaic constructions, and a style of argument that assumed familiarity with debates and texts that few readers today encounter. The aim of the present adaptation is to clear away those obstacles without sacrificing the substance, the logic, or the force of Locke’s reasoning. What remains is the argument in its full power, rendered in language that flows naturally for a modern audience. The hope is that readers who might once have been deterred by seventeenth-century English will now be able to follow Locke’s thought as clearly as his original readers did—and perhaps more clearly, since they will not have to pause every few lines to decode unfamiliar phrasing.

To appreciate why this work matters so much, it helps to understand the world from which it emerged. Locke lived through one of the most convulsive periods in English history. He was born in 1632, came of age during the English Civil War, witnessed the execution of a king and the brief experiment of a republic under Oliver Cromwell, and then saw the monarchy restored. The central question of his lifetime was the question of legitimate authority. Could a king rule by divine right, answerable to no one but God? Or did political power rest on some other, more human foundation? The dominant theory of the age, articulated most forcefully by writers like Sir Robert Filmer, held that kings inherited their authority from Adam himself, in an unbroken line of patriarchal succession ordained by God. On this view, subjects owed absolute obedience to their monarch, and to resist the king was to resist the will of heaven.

Locke found this idea not merely mistaken but dangerous, and the Second Treatise is in large part his answer to it. Where Filmer grounded authority in inheritance and divine command, Locke grounded it in something altogether different: the consent of free and equal individuals. This was a revolutionary inversion. Instead of asking what the king was owed, Locke asked what the people were owed. Instead of treating obedience as the default, he treated freedom as the default and obedience as something that required justification. The implications of this reversal were seismic, and we are still living inside them.

The work appeared in the immediate aftermath of the so-called Glorious Revolution of 1688, when the English Parliament effectively deposed King James II and installed William and Mary on the throne under conditions that limited royal power. For a long time, the Second Treatise was read as a justification written after the fact for that revolution. Modern scholarship, however, has revealed that Locke composed much of it earlier, during a period of intense political crisis and conspiracy when those who opposed the absolutist tendencies of the Stuart monarchy faced genuine peril. This matters because it tells us that the Second Treatise was not a comfortable, retrospective endorsement of a settled order. It was a daring and even dangerous argument, written in a climate where defending the right of resistance could cost a person dearly. There is real courage in its pages, and a sense of stakes that the smooth surface of its reasoning sometimes conceals.

To read this book well, it helps to have a map of the terrain Locke covers, for though his argument unfolds step by step, it builds toward conclusions that may not be obvious from the opening chapters. Locke begins not with kings or parliaments but with a thought experiment: imagine human beings before any government existed at all. What would their condition be? This is what he calls the “state of nature,” and it is one of the most important and frequently misunderstood ideas in the entire work.

For Locke, the state of nature is not a condition of chaos or savagery, as some other thinkers imagined it. It is a state of freedom and equality, governed by what he calls the “law of nature”—a moral order accessible to human reason. In this original condition, no one is naturally the ruler of anyone else. Every person is free to act as they see fit and to dispose of their possessions and persons as they wish, within the bounds of the natural law, which teaches that “no one ought to harm another in his life, health, liberty, or possessions.” This is a profound starting point, because it means that any subordination of one person to another, any authority that some hold over others, must be explained. It cannot simply be assumed. Freedom comes first; restraint must be justified.

From this foundation, Locke develops his account of why people would ever choose to leave such a state of natural freedom and submit themselves to government. The answer lies in the inconveniences of the state of nature. Although people in this condition possess natural rights, they have no impartial judge to settle disputes, no established and known law that everyone agrees upon, and no reliable power to enforce justice. Each person must be the judge in their own case, which inevitably leads to conflict, partiality, and insecurity. To remedy these defects, individuals agree to come together and form a political society, surrendering some of their natural freedom in exchange for the protection of an impartial authority that can make laws, judge disputes, and enforce the rules. Crucially, this surrender is partial and conditional. People do not hand over everything; they retain their fundamental rights, and they grant power to government only for specific purposes—chiefly the preservation of their lives, liberties, and property.

This brings us to one of Locke’s most celebrated and consequential contributions: his theory of property. Long before modern debates about ownership and economic rights, Locke offered a striking argument for how legitimate private property arises. In the state of nature, he reasons, the earth and its resources are given to all humanity in common. So how does anything become the rightful possession of a single individual? Locke’s answer is that each person owns their own body and, by extension, their own labor. When a person mixes their labor with something from the common store—when they till the soil, gather the fruit, or shape the raw material—they make it their own. Property, on this view, is rooted in work and in the natural right each person has over themselves. This argument has been enormously influential, shaping debates about economics, ownership, and individual rights right down to the present day. It is also one of the more contested parts of Locke’s thought, and reading it carefully repays the effort, for it reveals both the power and the limits of his vision.

The reader should pay particular attention to the way Locke distinguishes between different kinds of power and the careful limits he places on each. He separates the power a father has over his children, the power a master has within a household, and the political power that government exercises over citizens. These are not the same, he insists, and conflating them—as the defenders of absolute monarchy did—leads to grave errors. Political power, for Locke, is uniquely a public trust. It exists for the good of those who are governed, and it is held conditionally, on the understanding that it will be used for its proper ends. This is the heart of what makes his theory so radical and so enduring.

Equally important is Locke’s treatment of the structure of government itself. He argues for what we would now recognize as a separation of powers, distinguishing the legislative power that makes laws from the executive power that enforces them. The legislative power, for Locke, is supreme, because it expresses the collective will of the society, but even it is not unlimited. It is bound by the natural law, by the requirement to govern through established and public rules rather than arbitrary decrees, and by the obligation to serve the common good. No legitimate authority, in Locke’s scheme, can rule by whim, seize property without consent, or place itself above the law it administers. These principles—government by law, accountability of rulers, limits on power—form the backbone of constitutional thought as we know it.

And then there is the conclusion toward which the whole argument drives: the right of resistance. This is the most dangerous and the most exhilarating part of the Second Treatise. If government exists to protect the rights of the governed, and if it is a trust held on their behalf, then what happens when rulers betray that trust? What happens when they turn their power against the very people they were meant to serve, when they govern arbitrarily, seize property, or place themselves above the law? Locke’s answer is unflinching. When government becomes tyranny—when it ceases to serve its purpose and instead makes war upon the people—it dissolves the bonds of obligation. The people, who are the original source of political authority, may then resume that authority and establish a new government. This is not a license for casual rebellion; Locke is careful to argue that people will tolerate a great deal before they rise up, and that resistance is justified only against a long train of abuses, not against ordinary errors or single missteps. But the principle is unmistakable: ultimate authority resides not in the ruler but in the people, and a government that violates its trust forfeits its claim to obedience.

It is worth pausing to appreciate just how electrifying this conclusion was, and how far its consequences would travel. The idea that the people are the source of political power, that government is accountable to them, and that they retain the right to alter or abolish a government that turns tyrannical—this idea would later be carved into the founding documents of nations and proclaimed in the streets of revolutionary cities. When we read in the American Declaration of Independence that governments derive “their just powers from the consent of the governed,” and that whenever a government becomes destructive of the ends for which it was established, “it is the right of the people to alter or to abolish it,” we are reading the distilled essence of the Second Treatise. Locke gave a philosophical vocabulary to the longing for self-government, and that vocabulary has never gone out of use.