Consider what the state actually does to you. It takes a portion of your earnings without asking your individual consent. It makes rules you must follow on pain of punishment. It claims, alone among all the actors in society, the right to use force legitimately — to fine you, to arrest you, in the last resort to lock you up. If anyone else behaved this way we would call it extortion and kidnapping. When the state does it, we call it government, and most of us obey without a second thought.
Why? What gives the state the right? This is not an idle question for seminar rooms. It is the deepest question in political philosophy, the one beneath all the others, because every argument about taxes, liberty, justice and law eventually traces back to it. If we cannot say why the state is legitimate, we cannot say what it may rightfully do. The thinkers who have wrestled with this question have left us not a single answer but a set of rival, illuminating attempts — and each still shapes the way we argue about politics today.
The social contract: government by agreement
The most influential answer is the idea of the social contract. Imagine, the contract theorists ask, a world before government — a “state of nature” with no laws, no police, no courts, no state at all. What would life be like? And would rational people, looking at that condition, choose to create a state? If they would, then the state is justified not by force or tradition but by something like consent.
Thomas Hobbes, writing amid the chaos of the English Civil War, gave the bleakest picture. Without a common power to keep everyone in awe, he argued, life would collapse into a “war of all against all,” and human existence would be “solitary, poor, nasty, brutish, and short.” To escape this terror, people would rationally surrender their freedoms to a sovereign with near-absolute power. Any government, however harsh, was better than the anarchy it prevented. For Hobbes, the state was legitimate because it delivered the one thing we cannot do without: order.
John Locke offered a gentler version that has proved more enduring. His state of nature was not a war but an inconvenience: people had natural rights to life, liberty and property, but no impartial authority to protect them. So they agreed to form a government — and here is the crucial move — only to secure those rights. Government, for Locke, is a trust. Its authority is conditional on protecting the rights it was created to protect. If it instead tramples them, it breaks the contract, and the people may rightfully resist. This idea, that legitimate power rests on consent and serves the governed, runs straight into the bloodstream of modern liberal democracy.
The social contract reframes obedience: we obey not because we must, but because, on reflection, rational people would agree to a state like this.
Jean-Jacques Rousseau pushed the idea further still, arguing that true legitimacy comes only when citizens collectively govern themselves according to the “general will” — the common good they share as a community. Freedom, for Rousseau, was not the absence of rules but obedience to laws we give ourselves.
The contract is a powerful device, but it has an obvious weakness. You never actually signed anything. No one alive consented to the state they were born into. Theorists answer with notions of tacit consent — by living here, using the roads, enjoying protection, you implicitly accept the deal — but the question of whether that really counts as agreement has never been fully laid to rest.
Liberty and the harm principle: where does the state stop?
Grant that the state is legitimate. A second great question immediately follows: how far may it reach into our lives? Even a justified state can become tyrannical if it controls too much. Where is the line between the authority of society and the freedom of the individual?
The most famous answer belongs to John Stuart Mill, in his essay On Liberty. Mill proposed a single, sharp test, the harm principle:
The only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others.
The implications are radical. Over your own body and mind, over choices that affect only yourself, you are sovereign. The state — and society more broadly — may stop you from harming others, but may not coerce you for your own good, however foolish your choices seem. Mill was fiercely opposed to paternalism and to the “tyranny of the majority,” the pressure of public opinion that can crush dissent and eccentricity as surely as any law. His defence of free thought and free speech rests on the idea that even mistaken opinions are valuable, because they sharpen the truth.
The harm principle sounds clean but turns slippery in practice. What counts as “harm to others”? Does offence count? What about harms that are indirect, or harms we do to ourselves that burden others? Debates about everything from seatbelt laws to drug policy to free expression are, at heart, arguments about where Mill’s line falls. That a single sentence from the 1850s still frames these disputes is a measure of its power.
Theories of justice: Rawls and Nozick
The third great question is perhaps the most pressing: not whether the state is legitimate, nor how far it may reach, but what a just society would actually look like. How should the benefits and burdens of social life — wealth, opportunity, rights — be distributed? Here two twentieth-century philosophers laid out positions so opposed, and so carefully argued, that much of modern political debate plays out between them.
John Rawls asked us to imagine designing the rules of society from behind a veil of ignorance. Suppose you had to choose the principles of justice without knowing who you would be in that society — rich or poor, talented or not, healthy or sick, born to advantage or disadvantage. Stripped of self-interest, Rawls argued, rational people would choose principles that were fair to everyone, because any of them might end up at the bottom.
From this thought experiment Rawls derived two principles. First, each person should have the most extensive basic liberties compatible with the same for others. Second — his famous difference principle — inequalities are justified only if they work to the benefit of the least advantaged members of society. A just society, on this view, is not one of perfect equality, but one whose inequalities can be justified to those who have the least. Rawls gave modern liberal and social-democratic thought its most rigorous philosophical foundation.
Robert Nozick replied with a forceful libertarian challenge. Justice, he argued in Anarchy, State, and Utopia, is not about the pattern of who has what, but about the history of how they came to have it. If you acquired your holdings justly — through legitimate work, voluntary exchange or gift, without force or fraud — then they are rightfully yours, and no one, including the state, may redistribute them to fit some preferred pattern. To tax the fruits of someone’s labour in order to give to others is, on Nozick’s account, to treat that person as a means to others’ ends, a violation of their rights. He argued for a minimal state, limited to protecting people against force, theft and fraud, and enforcing contracts — and nothing more.
The clash between Rawls and Nozick is not a quarrel about details. It is a fundamental disagreement about what justice is. Is it about fair outcomes, judged from an impartial standpoint? Or about respecting individual rights and the history of fair exchange, whatever outcomes result? Almost every argument about tax, welfare, public services and the proper size of the state is, underneath, a contest between these two visions.
Questions without final answers
What is striking about all of this is that the questions have never been settled — and perhaps cannot be. We still do not agree on why the state is legitimate, how far its reach should extend, or what a just distribution looks like. These are not failures of philosophy. They are the permanent tensions of living together: between order and freedom, between the individual and the collective, between fairness and rights.
The value of the great political philosophers is not that they hand us answers to memorise. It is that they hand us better questions, and the conceptual tools to argue about them well. When you next hear a debate about a tax, a freedom or a law, listen for the older arguments humming underneath. Someone is appealing to consent, someone to harm, someone to fairness, someone to rights. The seminar never really ended. It simply moved into the world, where we are all, whether we notice it or not, still answering the oldest political question of all: why should anyone obey the state?