Rawls' Theory of Justice

A thought experiment — design society without knowing who you will be in it — reshaped political philosophy in a single move.

Political philosophy in the middle of the twentieth century was, by most accounts, quiet. Utilitarianism dominated the English-speaking world, but almost by default: not because it had won any deep argument, but because its rivals had gone silent. Then in 1971 a Harvard professor named John Rawls published a six-hundred-page book called A Theory of Justice, and the field woke up. The book asked a very old question — what makes a society fair? — and answered it with a single, disarming move: imagine you have to design the rules before you know who you will be.

“Each person possesses an inviolability founded on justice that even the welfare of society as a whole cannot override.”

That opening sentence tells you what Rawls is doing. He is refusing, from the first line, the utilitarian move of trading one person's misery for another's happiness. Justice, on his account, is what a group of free and equal people would agree to as the ground rules for living together — and the trick is to set up the negotiation so no one can rig it.

The original position and the veil of ignorance

Rawls' central image is a thought experiment. Imagine the founders of a society sitting down to write the rules that will govern its basic structure: its constitution, the shape of its economy, how offices and opportunities are allocated. Now impose a strange constraint. Each founder is placed behind a veil of ignorance. They know general facts about human beings — that people have interests, that societies produce goods, that talents differ — but they do not know anything about themselves in particular:

You do not know your race, your sex, your class, your natural talents, your conception of the good life, your religion, or even which generation you belong to. You will be somebody in the resulting society — but the veil hides who. This is what Rawls calls the original position. It is a device, not a historical claim; nobody actually sits behind such a veil. But the constraint models something we already reach for in ordinary moral reasoning: fairness is what you would agree to if you did not know which side you would end up on. It is why we cut the cake and let the other person choose the slice.

Rawls' bet is that from behind this veil, rational self-interested people would not gamble on landing at the top. They would reason cautiously about the worst position they might occupy, because that position might be theirs. And on that basis, he argues, they would converge on two principles.

The two principles of justice

The first principle is about liberty. Each person is to have an equal right to the most extensive system of basic liberties compatible with the same for all — freedom of conscience, of speech, of association, the right to vote and hold office, physical integrity, the rule of law. Rawls holds that from behind the veil, no one would trade these away for money, since no one knows whether they will be part of the minority whose liberty gets sold. Liberties are equal, and they have priority: they cannot be traded for economic gains, even large ones.

The second principle governs social and economic inequalities, and it is where Rawls is most original. Inequalities are permitted only if:

(a) the positions attached to them are open to all under conditions of fair equality of opportunity, and (b) they work to the greatest expected benefit of the least advantaged members of society. Clause (b) is the famous difference principle. It says a society may have unequal outcomes — some doctors paid more than others, some entrepreneurs richer than most — but only when the inequality lifts the floor. Not when it merely raises the average.

Notice what this rules out. It rules out any argument of the form “yes, some people are worse off, but the total is larger.” It rules out any policy that sacrifices the bottom to lift the middle or the top. It does not rule out inequality — Rawls is not an egalitarian in the strict sense — but it makes the worst-off the moral centre of gravity, the group whose situation any deviation from equality must be justified to.

Objections and legacy

The book set off half a century of argument. Robert Nozick, three years later, replied with Anarchy, State, and Utopia. Justice, he said, is about how things came to be held, not how they are distributed at a snapshot. If your holdings arose from voluntary exchanges starting from a just baseline, they are just, whatever pattern they add up to; imposing a distribution requires continually interfering with people's free choices. Rawls' picture, on this view, treats human talents and effort as if they were a common pool.

Amartya Sen pressed a different objection. Even if we accept Rawls' framework, why measure the worst-off by their bundle of primary goods — income, rights, opportunities — rather than by what they can actually do? A person in a wheelchair and a person able-bodied might have the same income and still be very unequally free. Sen's capability approach grew out of that objection. Communitarian critics — Sandel, MacIntyre, Taylor — argued that Rawls' original position abstracts too much: real people are constituted by attachments, traditions, histories, and a philosophy that pretends they can step behind a veil to negotiate first principles is not describing agents anyone has actually met.

None of these objections finished Rawls off. He revised, replied, and in 1993 published Political Liberalism, softening the metaphysical claims and reframing the theory as a way for a pluralistic society to reach agreement despite deep disagreement about the good life. What survives, and what is now everywhere in political thought, is the basic apparatus: the veil of ignorance as a test for fairness, the maximin instinct that a society is judged by how it treats its worst-off, and the idea that inequality does not justify itself. When a politician says a policy is unjust because it burdens the poorest, or when a journalist asks whether a tax cut lifts the bottom or merely the top, that is Rawls talking, decades after the fact, from behind a veil.